WO2023250432A1

WO2023250432A1 - Fitness machines with adjustable shock absorption and methods of adjusting shock absorption for fitness machines

Info

Publication number: WO2023250432A1
Application number: PCT/US2023/068899
Authority: WO
Inventors: Kyle SPOO; Matt BRENNAND; Peter Kanakaris; Zhi Lu; Cory H. LAZAR; Juliette C. DALY
Original assignee: Life Fitness LLC
Current assignee: Life Fitness LLC
Priority date: 2022-06-24
Filing date: 2023-06-22
Publication date: 2023-12-28
Anticipated expiration: 2024-12-24

Abstract

A fitness machine providing shock absorption for a user operating the fitness machine. The fitness machine includes a base, at least one member engageable by the user and moveable relative to the base during operation of the fitness machine, and a resilient body that resists movement of the at least one member towards the base so as to provide shock absorption for the user, wherein the resistance provided by the resilient body is adjustable. The fitness machine further includes a control system configured to receive from the user a shock setting corresponding to how much shock absorption is desired, and to receive other than from the user a secondary input, wherein the control system is further configured to adjust the resistance provided by the resilient body based on the shock setting and the secondary input.

Description

FITNESS MACHINES WITH ADJUSTABLE SHOCK ABSORPTION AND

METHODS OF ADJUSTING SHOCK ABSORPTION FOR FITNESS MACHINES

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Patent Application No. 18/337,773, filed June 20, 2023, which claims the benefit and priority to U.S. Provisional Patent Application No. 63/355,147, filed June 24, 2022, which is incorporated herein by reference in its entirety.

FIELD

[0002] The present disclosure generally relates to fitness machines with adjustable shock absorption and methods for adjusting the stiffness of fitness machines.

BACKGROUND

[0003] The following U.S. Patents provide background information and are incorporated herein by reference in entirety.

[0004] U.S. Patent No. 11,458,356 discloses a fitness machine providing shock absorption for a user operating the fitness machine. The fitness machine includes a base and a member engageable by the user and moveable relative to the base during operation of the fitness machine. A resilient body resists movement of the member towards the base in a height direction. The resilient body has first and second ends defining a length therebetween, the length being defined in a length direction perpendicular to the height direction. A stop wall is engageable by the resilient body. The length of the resilient body increases when the member moves towards the base until the second end engages with the stop wall. The resilient body provides shock absorption for the user.

[0005] U.S. Patent No. 8,118,888 discloses a method to support a deck of an exercise treadmill one or more arcuate leaf springs are used in a deck support structure. The leaf springs can be made of a single member of elastomeric material. An adjustment mechanism can be used to change the radius of the leaf springs to vary spring rates of the leaf springs. Where different leaf springs are used, the adjustment mechanism can be used to adjust the spring rates of different springs independently. [0006] U.S. Patent No. 5,382,207 discloses a method to improve tracking, whereby an exercise treadmill is provided with a frame including molded plastic pulleys, having an integral gear belt sprocket, an endless belt extending around the pulleys and a motor operatively connected to the rear pulley to drive the belt. The pulleys are molded out of plastic and have a diameter of approximately nine inches. A mold and method for producing large diameter treadmill pulleys having an integrally molded sprocket are also disclosed. A deck underneath the running surface of the belt is supported by resilient members. A positive lateral belt tracking mechanism is used to correct the lateral position of the belt. A belt position sensor mechanism is used in combination with a front pulley pivoting mechanism to maintain the belt in the desired lateral position on the pulleys. The exercise treadmill also includes a lift mechanism with an internally threaded sleeve engaged to vertically aligned nonrotating screws. A user display of foot impact force on the belt is also provided.

[0007] U.S. Patent No. 7,628,733 discloses a method to provide variable resilient support for the deck of an exercise treadmill via one or more resilient members are secured to the deck and a moveable support member is used to selectively engage the resilient members to provide support for the deck. A user operated adjustment mechanism can be used to move the support member or support members longitudinally along the treadmill thus effectively changing the number of resilient support members supporting the deck.

[0008] U.S. Patent No. 6,572,512 discloses an exercise treadmill which includes various features to enhance user operation and to reduce maintenance costs. Sound and vibration are reduced in a treadmill by mounting the treadmill belt drive motor on motor isolation mounts that include resilient members. A further feature is a double-sided waxed deck where one side of the deck is covered by a protective tape.

[0009] U.S. Patent No. 6,783,482 discloses a microprocessor-based exercise treadmill control system which includes various features to enhance user operation. These features include programs operative to: permit a set of user controls to cause the treadmill to initially operate at predetermined speeds; permit the user to design custom workouts; permit the user to switch between workout programs while the treadmill is in operation; and perform an automatic cooldown program where the duration of the cooldown is a function of the duration of the workout or the user's heart rate. The features also include a stop program responsive to a detector for automatically stopping the treadmill when a user is no longer on the treadmill and a frame tag module attached to the treadmill frame having a non-volatile memory for storing treadmill configuration, and operational and maintenance data. Another included feature is the ability to display the amount of time a user spends in a heart rate zone.

SUMMARY

[0010] This Summary is provided to introduce a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

[0011] One aspect of the present disclosure generally relates to a fitness machine providing shock absorption for a user operating the fitness machine. The fitness machine includes a base, at least one member engageable by the user and moveable relative to the base during operation of the fitness machine, and a resilient body that resists movement of the at least one member towards the base so as to provide shock absorption for the user, wherein the resistance provided by the resilient body is adjustable. The fitness machine further includes a control system configured to receive from the user a shock setting corresponding to how much shock absorption is desired, and to receive other than from the user a secondary input, wherein the control system is further configured to adjust the resistance provided by the resilient body based on the shock setting and the secondary input.

[0012] In certain examples, the secondary input is based at least in part on a target muscle group for the user when operating the fitness machine.

[0013] In certain examples, the secondary input is based at least in part on a metabolic response of the user when operating the fitness machine.

[0014] In certain examples, the secondary input is based at least in part on historical adjustments of the resilient member from previous operation of the fitness machine.

[0015] In certain examples, the secondary input is based on a program for operating the fitness machine over a period of time. In further examples, the program includes simulated terrains that change over the period of time for operating the fitness machine, and wherein the secondary input is based at least in part on the simulated terrains. In further examples, the program includes random adjustments for the resistance provided by the resilient member over time, and wherein the secondary input is based at least in part on the random adjustments in the program. [0016] Certain examples further include a sensor that measures the movement of the at least one member towards the base during operation of the fitness machine, wherein the control system is further configured to generate a trend in the movement measured by the sensor over time, wherein the secondary input is based at least in part on the trend generated from the movement measured by the sensor.

[0017] Certain examples further include a sensor that measures the movement of the at least one member towards the base during operation of the fitness machine, wherein the control system is further configured to determine a position of a foot of the user on the at least one member engageable by the user, and wherein the secondary input is based at least in part on the position of the foot determined by the control system. In further examples, the position includes both a takeoff position and a landing position for the foot.

[0018] In certain examples, the resilient body is two or more resilient bodies that each resist movement of the at least one member towards the base, and wherein the control system is configured to adjust the resistances provided by two or more resilient bodies independently of each other based on the shock setting and the secondary input. In further examples, the fitness machine further includes a sensor that measures the movement of the at least one member towards the base during operation of the fitness machine, wherein the control system is further configured to determine a position of a foot of the user on the at least one member engageable by the user, and wherein the secondary input for independently adjusting the two or more resilient bodies is based at least in part on the position of the foot determined by the control system.

[0019] Another aspect of the present disclosure generally relates to a method for making a fitness machine providing shock absorption for a user operating the fitness machine. The method includes providing a base and at least one member engageable by the user and moveable relative to the base during operation of the fitness machine, and providing a resilient body that resists movement of the at least one member towards the base so as to provide shock absorption for the user, wherein the resistance provided by the resilient body is adjustable. The method further includes configuring a control system to receive from the user a shock setting corresponding to how much shock absorption is desired, and to receive other than from the user a secondary input. The method further includes adjusting the resistance provided by the resilient body based on the shock setting and the secondary input. [0020] In certain examples, the method further includes adjusting the resistance based on at least one of a target muscle group for the user and a metabolic response of the user when operating the fitness machine.

[0021] In certain examples, the method further includes adjusting the resistance based at least in part on historical adjustments of the resilient member from previous operation of the fitness machine. In further examples, the method further includes adjusting the resistance based at least in part on a program for operating the fitness machine over a period of time.

[0022] In certain examples, the method further includes measuring a movement of the at least one member towards the base during operation of the fitness machine, generating a trend of the movement over time, and adjusting the resistance based at least in part on the trend.

[0023] In certain examples, the resilient body is two or more resilient bodies that each resist movement of the at least one member towards the base, and wherein the resistances of the two or more resilient bodies are adjusted independently based on the shock setting and the secondary input. In further examples, the method further includes determining a position of a foot of the user on the at least one member engageable by the user, wherein the secondary input is based at least in part on the position of the foot determined by the control system.

[0024] Another aspect of the present disclosure generally relates to a method for making a fitness machine providing shock absorption for a user operating the fitness machine. The method includes providing a base and at least one member engageable by the user and moveable relative to the base during operation of the fitness machine, providing a resilient body that resists movement of the at least one member towards the base to provide shock absorption for the user, and adjusting the resistance provided by the resilient body based on a previous resistance from a previous operation of the fitness machine. The method further includes measuring the movement of the at least one member during operation of the fitness machine, determining whether the movement of the at least one member is beyond a threshold, and further adjusting the resistance provided by the resilient body when the movement is determined to be beyond the threshold. In certain examples, the method further includes storing the resistance provided by the resilient body as the previous resistance for future operation of the fitness machine.

[0025] It should be recognized that the different aspects described throughout this disclosure may be combined in different manners, including those than expressly disclosed in the provided examples, while still constituting an invention accord to the present disclosure. [0026] Various other features, objects and advantages of the disclosure will be made apparent from the following description taken together with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present disclosure is described with reference to the following drawing.

[0028] FIG. 1 is a perspective view of a fitness machine incorporating an exemplary adjustable shock absorption system according to the present disclosure;

[0029] FIG. 2 is a section view of a lower portion of the fitness machine of FIG. 1;

[0030] FIG. 3 is a close-up section view of the embodiment similar to that of FIG. 2;

[0031] FIG. 4 is a top-down view of the lower portion of the fitness machine of FIG. 1;

[0032] FIG. 5 is an exploded perspective view depicting a system similar to that of FIG. 2;

[0033] FIG. 6 is a close-up view of the system of FIG. 5;

[0034] FIG. 7 is a perspective view of an exemplary resilient body such as may be incorporated within an adjustable shock absorbing system according to the present disclosure;

[0035] FIG. 8 depicts exemplary data for adjustable shock absorption systems according to the present disclosure, particularly the stiffness versus gap size between a resilient body and an end stop;

[0036] FIGS. 9A-9D depict further exemplary data for testing adjustable shock absorption systems according to the present disclosure;

[0037] FIG. 10 depicts an exemplary control system for operating adjustable shock absorption systems according to the present disclosure;

[0038] FIG. 11 depicts a sensor for measuring movement during operation of the fitness machine;

[0039] FIG. 12 depicts the sensor of FIG. 11 installed on the fitness machine of FIG. 2;

[0040] FIG. 13 is a flow chart of one method for adjusting shock absorption according to the present disclosure;

[0041] FIGS. 14 and 15 depict examples of terrains within a program used for adjusting shock absorption according to the present disclosure;

[0042] FIGS. 16 - 24 are flow charts each depicting examples of methods for adjusting shock absorption according to the present disclosure; [0043] FTG. 25 is a schematic view of another example of a fitness machine according to the present disclosure in which four resilient bodies arc independently adjustable for adjusting shock absorption.

[0044] FIG. 26 is graph of example data for determining a location of a user’s engagement with a fitness machine.

DETAILED DISCLOSURE

[0045] The present disclosure generally relates to fitness machines with adjustable shock absorption and methods for providing adjustable shock absorption for fitness machines, including systems in which the amount of shock absorption is adjustable. Through experimentation and development, the present inventors have identified new methods for controlling stiffness or shock absorption adjustments for fitness machines, along with new fitness machines configured to operate in this manner. One mechanism for effectuating adjustments to the shock absorption of a fitness machine according to the present disclosure is described in U.S. Patent No. 11,458,356. However, it should be recognized that the present disclosure also contemplates effectuating the adjustments to shock absorption using other mechanisms. Unless stated to the contrary, the terms “shock absorption” and “stiffness” may be interpreted interchangeably.

[0046] FIG. 1 depicts an exemplary embodiment of a fitness machine 1 incorporating an adjustable shock absorption system 40 according to the present disclosure. In the illustrated embodiment, the fitness machine 1 is a treadmill having a belt 2 that is rotated such that a user may run or walk on the belt 2. FIGS. 1 and 2 show the belt 2 having a running upper strand 3 and a returning lower strand 4 that continuously cycle about belt rollers 6 in a conventional manner. While the present disclosure principally discusses embodiments in which the fitness machine 1 is a treadmill having a motor that rotates the belt 2, it should be recognized that the present disclosure equally applies to treadmills in which forces by the user rotate the belt 2, as well as to fitness machines 1 other than treadmills (e.g., stair climbers).

[0047] The fitness machine 1 of FIGS. 1 and 2 is supported on a base 20 having a front 21 and rear 22, left 23 and right 24, and top 25 and bottom 26. Operation of the fitness machine 1 is controlled by a console 10 in a manner known in the art, which for example controls the speed of the belt 2, an incline of the belt 2 relative to a horizontal plane (e.g., via a height adjustment system 30 in a manner known in the art), resistance levels (for example with bicycles, rowers, elliptical trainers, and/or treadmills in which the user rotates the belt), and/or other functions customary for operating fitness machines 1, as known in the art. The base 20 of the fitness machine 1 is supported on feet 14 and casters 12.

[0048] Fitness machines presently known in the art typically have a fixed or minimally adjustable "stiffness”. In the case of treadmills, this may mean the stiffness of the running surface, for example. Stiffness settings may be adjusted as a matter of personal preference, and/or for uses that require an especially “soft” stiffness.

[0049] In view of this, the fitness machine 1 of FIG. 1 also includes manual controls 116 for adjusting the stiffness of the fitness machine. The manual controls 116 may be moveable by the user in a manner similar to systems known in the art (e.g., here, selectable among 4 stiffness or shock absorption settings). Stiffness settings may also or alternatively be effectuated (e.g., via actuators or other mechanisms discussed below) in response to user inputs received by the console. User inputs directly relating to shock absorption are also referred to as first inputs or shock settings, such as user selections on a scale between “hard” and “soft” or selecting “concrete” versus “grass”. [0050] FIGS. 2-3 depict two exemplary systems 40 for providing shock absorption according to the presently disclosure, and specifically systems 40 in which the shock absorption is adjustable to provide a range of stiffness selections. The fitness machine 1 includes a base 20 and at least one member 42 that is engageable by the user, which consequently moves relative to the base 20 during operation of the fitness machine 1. The member 42 shown is a running deck that supports the belt 2 in a conventional manner, which moves up and down relative to the base 20 from the impact of the user running or walking thereon.

[0051] The systems 40 include one or more resilient bodies, shown here as leaf springs 50, that resist movement of the member 42 towards the base 20, particularly in a height direction HD. In certain embodiments, the leaf spring 50 is made of an elastomeric material, such as rubber, polyurethane, and/or other polymers.

[0052] The embodiments shown in FIGS. 2-4 each include four distinct and separate leaf springs 50 that work independently. These leaf springs 50 are each configured to function in the same or in a similar manner as the others. Thus, for simplicity, the leaf spring 50 and corresponding function are presently discussed singularly. Likewise, the leaf spring 50 described herein may be used in combination with one or more other shock absorbing devices presently known in the art. [0053] FTG. 7 depicts a close-up view an exemplary leaf spring 50 as incorporated within the system 40 of FIGS. 2-4. The leaf spring 50 is a resilient body that extends between a first end 51 and second end 52. A length L is defined between the first end 51 and the second end 52 in a length direction LD that is perpendicular to the height direction HD. The leaf spring 50 has a parabolic shape that opens downwardly and supports the member 42 at or near a vertex 54 of the parabolic shape. In the example shown, the member 42 rests on the leaf spring 50 without being coupled to the member 42.

[0054] A first pin hole 55 extends transversely through the leaf spring 50 at the first end 51 , and in certain embodiments a second pin hole 57 also extends transversely through the leaf spring at the second end 52. The first pin hole 55 (and second pin hole 57 when present) are each configured to receive a pin such as first pin 66 therethrough, as discussed below. The first end 51 and second end 52 have a substantially circular side profile that is thicker in the height direction HD than the resilient body therebetween for added strength. The first pin hole 55 and second pin hole 57 each also have substantially circular side profiles that are approximately centered within the circular profiles of the first end 51 and the second end 52. However, this is merely an exemplary configuration for the leaf spring 50, which may be configured to have differing side profiles between the first end 51 and the second end 52 to alter the characteristics of the shock absorption provided by the leaf spring 50, for example.

[0055] FIGS. 3 and 5-6 depict how these leaf springs 50 may be coupled between the base 20 and the member 42, shown here for an adjustable shock absorption system 40 similar to that of FIG. 2. The first end 51 of the leaf spring 50 is pivotally coupled to the base 20 via a bracket 60. The bracket 60 includes a plate 62 with a bottom segment 197 extending perpendicularly away from the plate 62. The plate 62 is coupled to the inside of the base 20, for example via welding, fasteners (e.g., nuts and bolts), or other methods presently known in the art. Two ears 195 extend upwardly from the bottom segment 197 and are substantially parallel to the plate 62. A first pin hole 53 extends through each of the ears 195, the interiors of the first pin holes 53 being smooth or threaded depending on the first pin 66 to be received. The first pin holes 53 are configured to receive a first pin 66, where the first pin 66 is also being received through the first pin hole 55 in the first end 51 of the leaf spring 50 to pivotally couple the leaf spring 50 to the bracket 60. [0056] Returning to FIG. 7, an exemplary first pin 66 is shown extending between a head 143 and tip 141 with a smooth shaft therebetween. An opening 145 is defined near the tip 141 for receiving a cotter pin 147 after the first pin 66 has been received through the bracket 60 (and through the first end 51 of the leaf spring 50). It should be recognized that the bracket 60 depicted in FIG. 7 is shown as only a partial view so as to not obscure the first pin hole 55, omitting the ears 195, for example. Other types of fasteners known in the art may also or alternatively be used as the first pin 66, including those with set screws, threads (e.g., engaging with a nut 67 as shown in FIG. 3), or press fits, those integrated with the leaf spring 50 (e.g., via over-molding), those welded to the bracket 60, and/or those used in conjunction with ears 195 of the bracket 60 that prevent lateral translation of the first pin 66, for example. These same examples for the first pin 66 also apply to a second pin 82 for the second end 52 of the leaf spring 50, which is discussed below. [0057] In this manner, the leaf spring 50 is permitted to freely rotate about the first pin 66, but the first end 51 is prevented from translating in the length direction LD or in the height direction HD relative to the base 20.

[0058] As shown in FIGS. 5-6, the systems 40 further include end stops 70 that are fixable relative to the base 20, in the present embodiment in an adjustable manner. A separate end stop 70 is shown provided for each leaf spring 50 in a similar manner as the brackets 60. However, other configurations are also contemplated. For simplicity, the end stops 70 are principally discussed singularly. In the embodiment of FIGS. 5-6, each end stop 70 extends from a top 156 to bottom 158 with a vertical segment 162 therebetween. Holes 160 are provided through the bottom 158 of the end stop 70 for mounting the end stop 70 to the base 20, specifically via a frame 100 to be discussed further below. The holes 160 receive threaded studs 166 that extend upwardly from the frame 100, in this example four threaded studs 166 for each end stop 70. Nuts 168 engage the threaded studs 166 to retain the end stops 70 on the frame 100. It should be recognized that other methods may be used for coupling the end stops 70 to the frame 100, including welding, other types of fasteners, and/or the like.

[0059] For each end stop 70, a floor 164 extends perpendicularly from the vertical segment 162, which intersects at a front end to a stop wall 80 connecting the floor 164 to the top 156. In the embodiment of FIGS. 5-6, the stop wall 80 is concaved such that a lip 154 extends rearwardly from the top 156 where the top 156 meets the stop wall 80. The contour of the stop wall 80 is configured in this manner to correspond with the contour of the second end 52 of the leaf spring 50, for example having a same approximate diameter. The second end 52 of the leaf spring 50 can thus slide forwardly along the floor 164 of the end stop 70 in the length direction LD until it engages the stop wall 80. The lip 154 that extends rearwardly from the top 156 is thus configured to prevent the second end 52 of the leaf spring 50 from moving upwardly in the height direction HD upon contacting the stop wall 80. It should be recognized that the lip 154 is not required and other forces such as the weight of the member 42 and the user also act to prevent movement of the second end 52 upwardly in the height direction HD. Likewise, the leaf spring may be configured such that the second end 52 moves via roller bearings or other mechanisms rather than sliding along the floor 164.

[0060] Certain embodiments of systems 40 provide that the position each end stop 70 is adjustable in the length direction LD relative to the base 20, which as will become apparent provides adjustability of the stiffness for the fitness machine 1. As shown in FIGS. 3 and 7, a gap G exists between the second end 52 of the leaf spring 50 (or in certain embodiments discussed below, a second pin 82 extending therethrough) and the stop wall 80 of the end stop 70. This gap G is greater when the user is not generating any force on the member 42, for example when the user is mid-air while running on a treadmill. Since the stop wall 80 limits the forward translation of the second end 52 of the leaf spring 50, the gap G between the second end 52 and the stop wall 80 can be adjusted to modify the amount and/or characteristics of shock absorption being provided by the leaf spring 50.

[0061] The position of the stop wall 80 for an end stop 70 is adjustable by moving the support frame 100 to which the end stop 70 is coupled, as described above. As shown in FIGS. 4-5, the support frame 100 includes cross members 104 extending between a first end 125 and a second end 127 that run perpendicular to the length direction LD, as well as side members 102 extending between a first end 121 and second end 123 and a mid-support 103 extending between a first end 131 and second end 133 that all run parallel to the length direction LD. The cross members 104, side members 102, and mid-support 103 may vary in number from that shown and may be coupled together and/or integrally formed, for example. The end stops 70 are coupled to the support frame 100 such that when multiple leaf springs 50 are provided, one or more leaf springs 50 (and therefore the gaps G associated therewith) are adjustable together.

[0062] With reference to FIGS. 4-6, the support frame 100 is translatable relative to the base 20 in the length direction LD via engagement within a track system 90. In this embodiment, support beams 196 extend inwardly from the base 20, each of which having a hole 198 in the height direction HD. A base 188 rests on the top of the support beam 196. In the example shown, the base 188 includes a plate 190 that rests on the top of the support beam 196, and wall 192 extending perpendicularly downwardly from the plate 190. The wall 192 engages with an inside edge of the support beam 196 to prevent rotation of the base 188 relative to the support beam 196. [0063] An elongated hole 194 is provided through the plate 190 of base 188. An elongated standoff 184 having an exterior shape substantially matching the interior shape of the elongated hole 194 is received in part within the elongated hole 194. A hole 186 is defined through the elongated standoff 184 in the height direction HD, which in the present example has a circular cross section. As shown in FIG. 6, the elongated standoff 184 is also received in part within a slot 170 defined within the support frame 100, specifically through the side members 102 in close proximity to the mounting location of each end stop 70. The exterior shape of the elongated standoff 184 is also configured to have a width 187 corresponding to a width of the slot 170 in the support frame 100. In the example shown, a top of the elongated standoff 184 is substantially flush with a top for the side member 102 of the support frame 100 when assembled.

[0064] A flanged coupler 172 has a flange top 176 with a barrel 174 extending downwardly therefrom. A hole 178 is defined through the flanged coupler 172. The barrel 174 is configured to have an outer diameter corresponding to the interior diameter of the hole 186 in the elongated standoff 184 such that the barrel 174 is received therein. When assembled, the underside of the flange top 176 is approximately flush with the top of the side member 102, preventing movement in the height direction HD. A fastener 180 (e.g., a bolt) having a head 182 is received through the flanged coupler 172, the elongated standoff 184, the base 188, and the hole 198 in the support beam 196 and threadingly engages a nut 183 on the opposite side of the support beam 196. It should be recognized that alternate methods of fastening known in the art may also be used. Once coupled together in this manner, the support frame 100 is translatable in the length direction LD by the elongated standoff 184 sliding within the slot 170, but prevented from rotating (i.e., due to like-engagement between the support frame 100 and other support beams 196 of the base 20), moving transversely, or moving in the height direction HD.

[0065] It should be recognized other embodiments may incorporate multiple, separate support frames 100 and corresponding actuators (discussed below) for changing the positions of one or more leaf spring 50 separately from other leaf springs 50. For example, leaf springs 50 could be adjusted independently, all together, or in subgroups. Tn certain embodiments, two support frames 100 may be provided to enable separate adjustment between front and rear pairs of leaf springs 50. This separation of adjustability enables one set of leaf springs 50 to travel a greater distance than another set of leaf springs 50. In another embodiments (see e.g., FIG. 25), the fitness machine 1 has four leaf springs 50 generally corresponding to the front-left, front-right, back-left, and back-right regions of the member 42 that is engageable by the user (e.g., a running deck), allowing independent adjustment of the resistance provided by the leaf springs 50 both front to back and left to right.

[0066] The support frame 100 and particularly its position in the length direction LD may be moved and locked in place using various forms of hardware known in the art. For example, a manual adjustment mechanism may be provided, such as a threaded hand crank or fasteners coupling the support frame 100 to discrete openings within the base 20 (e.g., the manual controls 116 of FIG. 1 in a manner known in the art). Alternatively, cam locks as presently known in the art may be used to lock the support frame 100 to the base 20 once in the desired position, for example. The locking hardware may be electrically actuated, including electrically actuated cams.

[0067] With reference to FIG. 3-5, the support frame 100 is moveable via an actuator 110, which may be operated via electrical momentary switches, a control system 200 as discussed below (including via the console 10), or other methods known in the art. The actuator may be an electrical, pneumatic, and/or hydraulically actuator known in the art. For example, a mechanism similar to a conventional height adjustment system 30 (see FIG. 1) for a treadmill could be employed to move the support frame 100. One such commercially available height adjustment mechanism is Treadmill incline motor lift actuator 0K65-01192-0002 / CMC-778, produced by P-Tech USA. The actuator 110 may also itself provide the locking function for the positioning of the support frame 100. It should be recognized that while the present disclosure principally focuses on actuators 110 that make adjustments in the length direction LD, other configurations are also contemplated.

[0068] The actuator 110 is coupled between the base 20 and a front end 101 of the support frame 100 to translate the support frame 100 relative to the base 20 in the length direction LD. Specifically, a first end of the actuator 110 is coupled to a cross member 126 of the base 20 with brackets 119 and fasteners 117, such as bolts, pins, and/or the like. An opposite end of the actuator 110 is coupled to the support frame 100, also via a bracket 1 19 and fastener 117 in a conventional manner, which may be the same bracket 119 and/or fastener 117 provided between the actuator 110 and the cross member 126 as described above. It should be recognized that the actuator 110 may be coupled between the base 20 and support frame 100 in alternate positions as well. Likewise, other types of actuators 110, including scissor-type actuators, rack and pinion actuators, and/or other configurations known in the art may also be used. It should be recognized that multiple types of actuators 110 may also be used to adjust the shock absorption provided by one or more leaf springs 50.

[0069] The exemplary actuator 110 of FIGS. 4-5 includes a motor 112 that rotatably engages with a gearbox 113. Rotation of the motor 112 extends or retracts a rod 114 relative to a housing 115 of the gearbox 113 in the length direction LD. Specifically, rotation of the motor 112 in a first direction causes rotation of the rod 114 through the gearbox 113, where a threaded engagement between the outer diameter of the rod 114 and the interior of the housing 115 causes the rod 114 to extend or retract in the length direction LD relative to the housing 115 as the motor 112 rotates. In contrast, rotation of the motor 112 in an opposite direction causes retraction of the rod 114 in the opposite manner. It should be recognized that either the rod 114 or the housing 115 may be coupled to the support frame 100 (with the other to the base 20), depending on the configuration of the actuator 110. In this manner, operating the actuator 110 causes movement of the support frame 100 relative to the base 20. This movement of the support frame 100 consequently adjusts the gap G between the leaf springs 50 and the stop walls 80 of the corresponding end stops 70, as discussed above. In the example shown, all leaf springs 50 are adjusted simultaneously and equivalently (i.e., a same distance in the length direction LD).

[0070] With reference to FIGS. 3-4, it should be recognized that the length L between the first end 51 and the second end 52 of the leaf spring 50 is caused to increase when the member 42 moves towards the base 20 during operation of the fitness machine 1. In other words, the parabolic shape of the leaf spring 50 is caused to flatten during use. However, the length L of the leaf spring 50 may be constrained by engagement between the second end 52 and the stop wall 80 of the end stop 70. Once the length L can no longer increase, the leaf spring 50 may further resist movement of the member 42 towards the base 20, but now through a different mechanism, namely, compression of its resilient material. Therefore, adjusting the gap G between the leaf spring 50 and the stop wall 80 of the end stop 70 adjusts the allowable length L of the leaf spring 50, and thus the profile of resistance provided by the system 40, which consequently adjusts the stiffness of the fitness machine 1.

[0071] The resistance provided by the system 40 varies depending upon whether the second end 52 of the leaf spring 50 is engaging the stop wall 80, creating two or more distinct phases. In an initial phase referred to as first phase Pl (discussed further below and shown in FIG. 6), the resistance provided by the leaf spring 50 against movement between the member 42 and the base 20 is primarily provided via bending deformation of the leaf spring 50. In other words, the length L of the leaf spring 50 may change, increasing as the member 42 moves towards the base 20. However, once the second end 52 engages with the stop wall 80 of the end stop 70 (or second pin 82 extending therethough for an embodiment discussed further below), which is been fixed relative to the base 20, a second phase P2 begins in which a length L of the leaf spring 50 can no longer change. At this stage, further movement of the member 42 towards the base 20 is resisted by the leaf spring 50 primarily by compressing the leaf spring 50, rather than by bending the leaf spring 50 as provide during phase 1 Pl. In other words, the parabolic shape can no longer get wider longer, and thus the leaf spring 50 starts to compress. In certain embodiments, the term “primarily” with respect to the basis for resistance means the basis has a greater contribution than any other basis (i.e., bending contributing to the resistance more than compressing contributes to the resistance). In certain embodiments, the basis having the greatest contribution provides more than 50% of the total resistance. In certain configurations, approximately 50%, 70%, 80%, 90%, 95%, or other portions of the stiffness is provided in phase 2 P2.

[0072] As shown in FIGS. 8 and 9A-9D, the resistance provided by the leaf spring 50, also referred to as spring stiffness, is thereby provided as a function of whether the resistance is in phase one Pl or phase two P2. Likewise, the selection of when a transition T from phase one Pl to phase two P2 occurs (i.e., the position of the member 42 relative to the base 20) is based upon the gap G provided between the second end 52 of the leaf spring 50 and the stop wall 80. In certain embodiments, the leaf spring 50 is selected such that the resistance provided in phase one Pl is substantially lower than the resistance provided in phase two P2. For example, in certain cases the spring stiffness in phase one Pl is no more than 50 percent of the spring stiffness in phase two P2. In further examples, the spring stiffness in phase one Pl is no more than 10 percent of the spring stiffness in phase two P2, or one order lower. [0073] It should be recognized that while the leaf spring 50 is shown providing a resi tance in each of the phases, here phase one Pl and phase two P2, the resistance may also be considered generally as a resistance profile. For example, the resistance need not be constant, nor linear within a given phase (such as in phase two P2 of FIG. 8). It should also be recognized that the larger the gap G between the second end 52 of the leaf spring 50 and the stop wall 80, the greater the deflection of the member 42 relative to the base 20 before phase 2 P2 is entered. In other words, a larger gap G provides for more deflection within the softer stiffness of phase one Pl. As discussed above, this allow the user to fully configure the stiffness of the shock absorption for the fitness machine 1, and specifically when this greater resistance of phase two P2 is felt by the user.

[0074] It should be recognized that additional phases may also be provided by the system 40 according to the present disclosure. For example, instead of pivotally fixing the first end 51 of the leaf springs 50 to the bracket 60, the first end 51 may also be translatable in the length direction LD in a similar or same manner as the second end 52. An example of this configuration is shown in FIG. 3, specifically for the forward-most bracket 60 shown. A stop wall 81 is integral with or coupled to the bracket 60, which provides a limit for the first end 51 of the leaf spring 50 moving rearwardly. The stop wall 81 thus prevents translation of the first end 51 of the leaf spring 50 without the use of a first pin 66. Other features may also be included to restrict movement of the first end 51 in the height direction HD, for example, such as the slot 74 discussed for the end stop 70 discussed above. In this embodiment, the first end 51 has a gap G2 of travel before being constrained by stop wall 81, thereby changing the overall resistance profile for the system 40 relative to the pivoting embodiment of the rear-most bracket 60 shown. Additional phases or impacts to the overall resistance profile may be provided by controlling one or more leaf springs 50 separately from others, such as having a gap G (and/or gap G2) that is greater for rear leaf springs 50 relative to forward leaf springs 50, for example.

[0075] It will also be understood that the leaf spring 50 need not be shaped as shown in the figures, which may also or alternatively vary in number and/or position relative to the base 20 and member 42 of the fitness machine 1. The positions of the leaf springs 50 relative to the base 20 may also be adjustable in ways other than adjusting the gap G between the leaf spring 50 and the stop wall 80 (and/or gap G2 for stop wall 81). Similarly, the end stops 70 may be adjustable in the height direction HD in addition to, or in the alternative to in the length direction LD, further modifying the manner in which the adjustments change the resistance profiles of the leaf springs 50. [0076] Additional testing results for a fitness machine 1 and system 40 as shown in Figs 2-4 arc provided in FIGS. 9A-9D, which were tested on a hydraulic MTS® test system in which the leaf springs 50 were compressed for 0.45 inches in the height direction HD in 2 Hz and 5 Hz sinusoidal motion-controlled mode. In the plots, the horizontal axes represent the amount of compression (the same for the four plots), while the vertical axes represent the applied forces to reach the corresponding deformations. The scale of the vertical axes is kip, or 1000 Ibf.

[0077] The curves demonstrate that there was little difference between responses under the two tested frequencies. FIG. 9D depicts the results when the leaf spring 50 was constrained at the original length L (no gap G to the stop wall 80), whereby the resultant force reached about 500 Ibf at 0.45 inch vertical travel. FIG. 9C was tested with 25% gap G (the percentage compared to the maximum gap, or equivalently the gap G needed to let the leaf spring 50 free bend into a straight beam. In this case, 25% was about 2.8 mm, where the peak loading reached about 400 Ibf. FIG. 9B was tested at 50% gap G (about 5.6 mm), where about 250 Ibf was needed to compress the spring down by 0.45 inch. FIG. 9 A was tested at 75% gap G, with maximum force of about 120 Ibf. Collectively these results demonstrate how the stiffness of the fitness machine 1 can be effectively controlled using the system 40 presently disclosed.

[0078] FIGS. 2-3 depict an alternative configuration for an end stop 70, which may be used alone or in conjunction with the end stop 70 discussed above for the system 40 of FIGS. 5-6. In this embodiment, the stop wall 80 is formed at the end or termination of a slot 74 defined within the sides of the end stop 70. Specifically, the end stop 70 has a top 71 with two arms 73 that extend rearwardly from a front 76 to fingertips 77. In the example shown, the fingertips 77 extend from the front 76 of the end stop 70 approximately the same distance as do base tips 79 such that a slot 74 is formed between the fingertip 77 and base tip 79 on each side of the end stop 70. As shown in the top-down review of FIG. 4, providing two arms 73 for each end stop 70 allows the leaf spring 50 to be positioned between the arms 73, which retains the leaf spring 50 in position relative to the left 23 and right 24 of the fitness machine 1.

[0079] This embodiment of end stop 70 is configured such that a second pin 82 extending through the second pin hole 57 in the second end 52 of the leaf spring 50 is translatable in the length direction LD within the slot 74. The second pin 82 is insertable into the slot 74 at least via the open end 75 opposite a stop wall 80 and front 76. The clearance C of the slot 74 is selected based on the diameter of the second pin 82 such that no movement is permitted in the height direction HD. Forward translation of the second end 52 of the leaf spring 50 may thus be prevented by engagement between the stop wall 80 and the second pin 82 extending through the second end 52, and/or engagement between the stop wall 80 and the second end 52 itself.

[0080] With continued reference to FIGS. 2-3, the second pin 82 may be the same or similar to the first pin 66, or be formed of other hardware known in the art. In certain examples, the second pin 82 and/or first pin 66 are rods retained in place via cotter pins and/or the like. In another example, the second pin 82 and/or first pin 66 are over-molded to be retained on the leaf spring 50 to extend outwardly therefrom, for example. Whether or not first pins 66 and/or second pins 82 are used, the leaf spring 50 may also or alternatively be coupled to the member 42, for example at the vertex 54.

[0081] The support frame 100 may be translatably moveable relative to the base 20 in the length direction LD via other configurations and mechanisms. FIG. 3 depicts an embodiment of a system 40 providing this adjustment via engagement via a different track system 90 than discussed above. This track system 90 includes a sliding track 92 that is coupled to the base 20 via track mounts 91. Specifically, a track riding bracket 94 is coupled to the support frame 100, for example on the side members 102. The track riding bracket 94 slidably engages with the sliding track 92, which may function similarly to a conventional drawer slide having roller bearings, incorporate a rack and pinion engagement, and/or other sliding mechanisms known in the art. The support frame 100 may then be locked relative to the base 20 in a manner known in the art and as discussed above.

[0082] FIG. 10 depicts an exemplary control system 200 for adjusting the stiffness for a fitness machine 1, which may be manually operated by the user and/or automatically selected or modified according to a given program controlled by the console 10. The control system 200 in certain embodiments automatically modifies the stiffness according to a changing program or other factors such as user’s body weight or fitness levels. For example, the stiffness may be automatically modified when a program for the fitness machine 1, such as a treadmill, transitions from simulating running on a trail versus running on a road (here, transitioning from soft to firm stiffnesses. In another example, each stiffness setting has an associated range of allowable deck deflection. If the actual deck deflection is outside the range for the chosen stiffness setting (e.g., a selection of “firm”), the stiffness may be automatically adjusted to bring the actual deck deflection within the allowable range. In some examples, the adjusted stiffness setting may be stored in memory for subsequent use, subsequent use with the same user (e.g., in the case of a user logging in to operate the fitness machine), and/or subsequent use with users of a similar weight. Similarly, there may be an allowable or preferred range of deck deflection for a given weight of the user, whereby adjustments are made to offset any deck deflections outside this range (i.e., by comparison to the user’s inputted weight). Any of the aforementioned adjustments can be made automatically in use of the treadmill, and/or during calibration or field testing by a technician.

[0083] Certain aspects of the present disclosure are described or depicted as functional and/or logical block components or processing steps, which may be performed by any number of hardware, software, and/or firmware components configured to perform the specified functions. For example, certain embodiments employ integrated circuit components, such as memory elements, digital signal processing elements, logic elements, look-up tables, or the like, configured to carry out a variety of functions under the control of one or more processors or other control devices. The connections between functional and logical block components are merely exemplary, which may be direct or indirect, and may follow alternate pathways.

[0084] In certain examples, such as shown in FIG. 10, the control system 200 communicates with each of the one or more components of the system 40 via a communication link CL, which can be any wired or wireless link. The control system 200 is capable of receiving information and/or controlling one or more operational characteristics of the system 40 and its various sub-systems by sending and receiving control signals via the communication links CL. In one example, the communication link CL is a controller area network (CAN) bus; however, other types of links could be used. It will be recognized that the extent of connections and the communication links CL may in fact be one or more shared connections, or links, among some or all of the components in the fitness machine 1. Moreover, the communication link CL lines are meant only to demonstrate that the various control elements are capable of communicating with one another, and do not represent actual wiring connections between the various elements, nor do they represent the only paths of communication between the elements. Additionally, the system 40 may incorporate various types of communication devices and systems, and thus the illustrated communication links CL may in fact represent various different types of wireless and/or wired data communication systems.

[0085] The control system 200 may be a computing system that includes a processing system 210, memory system 220, and input/output (I/O) system 230 for communicating with other devices, such as input devices 199 (e.g., a console and/or other user interfaces, sensors measuring movement of one or more members that arc cngagcablc by the user, such as a running deck) and output devices 201 (e.g., actuators, a motor to rotate a belt, etc.), either of which may also or alternatively be stored in a cloud 202. The processing system 210 loads and executes an executable program 222 from the memory system 220, accesses data 224 stored within the memory system 220, and directs the system 40 to operate as described in further detail below.

[0086] The processing system 210 may be implemented as a single microprocessor or other circuitry, or be distributed across multiple processing devices or sub-systems that cooperate to execute the executable program 222 from the memory system 220. Non-limiting examples of the processing system include general purpose central processing units, application specific processors, and logic devices.

[0087] The memory system 220 may comprise any storage media readable by the processing system 210 and capable of storing the executable program 222 and/or data 224. The memory system 220 may be implemented as a single storage device, or be distributed across multiple storage devices or sub-systems that cooperate to store computer readable instructions, data structures, program modules, or other data. The memory system 220 may include volatile and/or non-volatile systems, and may include removable and/or non-removable media implemented in any method or technology for storage of information. The storage media may include non-transitory and/or transitory storage media, including random access memory, read only memory, magnetic discs, optical discs, flash memory, virtual memory, and non-virtual memory, magnetic storage devices, or any other medium which can be used to store information and be accessed by an instruction execution system, for example.

[0088] The present inventors have identified new opportunities for controlling the stiffness or shock absorption of fitness machines in addition to, or as an alternative to, adjustments based on inputs relating directly to shock absorption (also referred to as first inputs). In particular, the present inventors have recognized that it would be advantageous to control the shock absorption of the fitness machine as a function of other inputs that do not directly relate to stiffness or shock absorption, such as a speed and/or an incline at which the fitness machine is being operated, a weight of the user, a program being executed (e.g., a particular running trail), and other factors discussed further below. These additional inputs are also referred to as secondary inputs to distinguish from the shock settings that relate directly to shock absorption. [0089] As is discussed further below, certain additional inputs are provided at least in part on sensors positioned on the fitness machine 1. FIG. 11 shows one sensor assembly 250 configured to detect motion of the member 42 as the user operates the fitness machine 1. The sensor assembly 250 is an arc sensor, such as the 100° Arc Sensor (Part No. 013-0047) produced by CambridgelC. The sensor assembly 250 includes an arc-shaped sensor 252 that extends in an arc between a first end 254 and a second end 256. The sensor assembly 250 is shown to be a 100° arc sensor, meaning that the first end 254 and the second end 256 are positioned so as to detect movement of up to 100° therebetween. The arc-shaped sensor 252 is coupled to the inside of a housing 260 and includes a chipset 262.

[0090] The sensor assembly 250 also includes an arm 270 that extends between a first end 272 and a second end 274. The arm 270 is pivotally coupled to the housing 260 (e.g., via a fastener such as a nut and bolt) so as to pivot about a pivot axis 276. A coil spring 279 is positioned between the arm 270 and the housing 260. The spring 279 biases the arm 270 so as to rotate the first end 272 of the arm 270 upwardly.

[0091] A finger 278 extends perpendicularly from the first end 272 of the arm 270. In certain embodiments, the finger 278 is a roller rotatable about an axis perpendicular to the first end 272 of the arm 270. A resonant inductive target, also referred to as a target 280, is provided at or near the second end 274 of the arm 270. The sensor assembly 250 is configured such that the arc-shaped sensor 252 detects the position of the target 280 between the first end 254 and the second end 256, in this case via inductance between the target 280 and the arc-shaped sensor 252. In this manner, the sensor assembly 250 detects movement of the first end 272 of the arm 270 by measuring the position of the target 280, which is communicated via the chipset 262 to the control system 200 discussed above via a cable 282.

[0092] The present disclosure also contemplates the use of other types of sensors for detecting movement, including by not limited to piezoelectric sensors, linear transducers (e.g., a linear Cambridge IC sensor with the target mounted on the edge of the deck and the PCG mounted on the frame adjacent to the target), inertial measurement units, a Hall-effect sensor, and/or optical sensors. By monitoring the deck deflection for a given user and a given shock absorption setting, the fitness machine 1 may be used detect characteristics of the user’s gait, such as running flatfooted, landing on toe, or landing on heel. This information can then be used to train the user to alter their running style, such as to prevent injury, improve left-right symmetry, or improve efficiency.

[0093] FIG. 12 shows the sensor assembly 250 of FIG. 11 installed on a fitness machine 1, here a treadmill. In particular, the sensor assembly 250 is coupled to the base 20 of the fitness machine 1 such that the finger 278 on the arm 270 of the sensor assembly 250 is in contact with the underside of the member 42. Contact is maintained between the member 42 and the finger 278 by the biasing provided by the spring 279 (i.e., biases the first end 272 of the arm 270 upwardly). [0094] As the user operates the fitness machine 1, it should be recognized that the member 42 moves up and down in the height direction HD in response to the impact of the user running on the member 42. The movement of the member 42 corresponding moves the first end 272 of the arm 270 of the sensor assembly 250, which is detected and communicated to the control system 200 via the cable 282 as discussed above. In this manner, the sensor assembly 250 detects movement of the member 42 in real-time during use of the fitness machine 1.

[0095] Other types of sensors may provide data to be used as additional inputs for the control system 200. For example, weight sensors (e.g., piezoelectric sensors) may be used to measure the weight of the user, speed sensors may be used to measure a rotational weight of a treadmill belt or bicycle cranks, and/or incline sensors or encoders may be used to measure an incline of a fitness machine 1 during use (e.g., the incline angle of a treadmill deck relative to the floor).

[0096] As discussed above, the present inventors have recognized that these additional inputs may be used to automatically adjust the shock absorption of the fitness machine 1, alone or in combination with inputs from the user directly relating to shock absorption (e.g., shock settings received from the user). FIG. 13 shows one embodiment of a method 300 for making a fitness machine providing shock absorption according to the present disclosure. Step 302 includes providing a base and at least one member engageable by the user and moveable relative to the base during operation of the fitness machine, as discussed above. In the case of a treadmill, the member is the deck supporting the belt. Step 304 also proceeds as discussed above, providing a resilient body that resists movement of the member towards the base so as to provide shock absorption for user. In Step 306, the control system 200 is configured to receive inputs for use in adjusting the shock absorption for the fitness machine. [0097] The inputs include first inputs (also referred to as shock settings) that relate to the shock absorption directly, for example how much shock absorption is desired by the user. As discussed above, this may be a selection among such options as “hard” versus “soft,” “beach” versus “concrete” or “boardwalk”, or a numeric value between 0 and 10 or 0% and 100%, for example. The first inputs may be received as stiffness selections provided via the console 10 discussed above (e.g., via a stiffness up arrow and a stiffness down arrow displayed on the screen), or as a preference saved in the memory system for a given user.

[0098] The inputs received by the control system 200 also include at least one secondary input that does not directly relate to shock absorption. Examples of secondary inputs include, but are not limited to the following, which are discussed further below:

• simulated terrains within a program that change over a period for time for operating the fitness machine;

• a speed at which the fitness machine is being operated;

• an incline of the at least one member during operation of the fitness machine;

• a target muscle group for the user when operating the fitness machine;

• a metabolic response of the user when operating the fitness machine;

• historic adjustments of the resilient member from previous operation of the fitness machine;

• random adjustments for the resistance provided by the resilient member over time;

• a measurement of the movement of the at least one member during operation of the fitness machine;

• a trend over time of a measurement of the movement of the at least one member towards the base during operation of the fitness machine;

• a weight of the user as provided, as stored in memory, and/or as measured;

• foot take-off position on the fitness machine;

• foot landing position on the fitness machine; and/or

• a position of the user on the fitness machine.

[0099] With continued reference to FIG. 13, Step 308 provides for adjusting the resistance provided by the resilient body (e.g., in one of the manners described above) based on both the shock setting, and on one or more secondary inputs. For example, the shock absorption may be controlled based on the user’s selection of desiring a relatively “soft” setting, but still vary between very soft and soft-medium as a program takes the user through terrain varying in this manner (e.g., starting on loose sand and ending on a wooden pier). It should be recognized that the present disclosure also contemplates methods in which only secondary inputs are used for adjusting the shock absorption for the fitness machine.

[0100] In certain embodiments, the secondary inputs are based on simulated terrains within a program that change over a period for time. By way of example, the treadmill products offered by Life Fitness, LLC of Rosemont, Illinois include Manual, Hill, and Random program selections. FIGS. 14 and 15 depict two programs 350 selectable for operating a fitness machine, respectively. The program 350 of FIG. 14 corresponds to a run along a dirt trail in a valley between mountains. The program 350 of FIG. 15 corresponds to a run on a brick and gravel path through historic portions of Germany. The display is updated over time as a function of the user’s pace in a manner known in the art (e.g., using metatags).

[0101] In addition to changing the visual display on the console as the user progresses through the programs 350 (visually simulating movement), the control system 200 automatically adjusts the shock absorption of the fitness machine based on the simulated terrain shown at any given time. For example, the program 350 of FIG. 14 may begin at a medium stiffness while the user appears to be running (i.e., the lower center of the screen is shown) on dirt 352, increasing to a medium-hard stiffness when running over stones 354, and decreasing to soft when running through the long grass 356.

[0102] Similarly, the program 350 of FIG. 15 may begin at a medium-hard stiffness when running on a first segment 358 (e.g., gravel), temporarily increasing to hard when running over the bricks of a second segment 360. It should be recognized that the control system 200 may effectuate other changes in accordance with the progress of the program, for example modifying the speed or incline, and/or varying the stiffness differently for one part of the fitness machine compared to others (e.g., the front left and rear left leaf springs becoming stiffer than the front right and rear right leaf springs when staggering mixed terrain).

[0103] Additional information is now provided for implementing the other examples of secondary inputs listed above. FIG. 16 provides a method 400 for adjusting the shock absorption based on a target muscle group for the user while operating the fitness machine, which begins upon receiving such a selection for operation in step 402. The specific muscle or muscles to be targeted are received in step 404, for example being selected from a group 406 of choices displayed on the console 10. A speed and incline are received in step 408 to begin the workout. Step 410 provides for retrieving stiffness settings (c.g., stored in the memory system 220 of FIG. 1) corresponding to the muscle group(s) selected in step 404 at the current speed and incline, such as an allowable range of deck deflection. It should be recognized that the allowable stiffness settings may be derived through other mechanisms, such as via algorithms rather than referencing data tables stored in memory. Step 412 provides for adjusting the stiffness as necessary to make the actual deck deflection fall within the allowable range as determined in step 410. This stiffness adjustment (as well as for other methods described herein) may be made automatically, in some cases by first prompting the user for confirmation (e.g., “Increase deck stiffness to target muscles of interest?”), or by prompting the user to make such an adjustment (e.g., displaying “Please increase the deck stiffness to engage the target muscles” or “Select at least a medium shock setting to engage target muscle(s)”)). A currently activated muscle group may also be displayed in text and/or as a graphic. The adjustment may also include requests or suggestion to change the speed or incline at the same time, either with or in place of deck stiffness adjustments. Any adjustments to the stiffness in step 410 may further be communicated to the user in step 414, for example via the console 10. If the user is determined in step 416 to change the speed or incline of the fitness machine, the process returns to step 410 to again retrieve or determine the corresponding deck deflection range allowable for that speed, incline, and target muscle group selection.

[0104] FIG. 17 shows a method 500 using speed for adjusting shock absorption, which begins upon receiving such a selection for operation in step 502, as well as a speed setting in step 504, in a conventional manner. Step 506 provides for retrieving or otherwise determining stiffness settings corresponding to the speed selected in step 504. Step 508 provides for adjusting the stiffness as necessary to make the actual deck deflection fall within the allowable range determined in step 506. Any adjustments to the stiffness in step 508 may further be communicated to the user in step 510, for example via the console 10. If the user is determined in step 512 to change the speed of the fitness machine, the process returns to step 506 to again retrieve or determine the corresponding deck deflection range allowable for that speed. In other examples, adjustments to the stiffness may be made without respect to actual deck deflection, such as increasing the stiffness as a function of increasing speed, increasing stiffness when the user is determined to be running versus walking (determined in a manner known in the art), or decreasing stiffness during warm up, cool down, or interval training recovery phases of a workout program. [0105] FIG. 18 shows a method 600 for using the incline of the fitness machine for adjusting shock absorption, which begins upon receiving such a selection for operation in step 602, as well as a speed and incline settings in step 604, in a conventional manner. Step 606 provides for retrieving or otherwise determining stiffness settings corresponding to the incline and speed selected in step 604. Step 608 provides for adjusting the stiffness as necessary to make the actual deck deflection fall within the allowable range determined in step 606. Any adjustments to the stiffness in step 608 may further be communicated to the user in step 610. If the user is determined in step 612 to change the speed or incline of the fitness machine, the process returns to step 606 to again retrieve or determine the corresponding deck deflection range allowable for that speed and incline.

[0106] FIG. 19 shows a method 700 for using a metabolic response of the user when operating the fitness machine for adjusting shock absorption, which begins upon receiving such a selection for operation in step 702, as well as a goal in step 704 (for example among the group 706 of choices that may include maximum calorie burning or maximum efficiency). User selections of speed and incline settings are also received in step 708 in a conventional manner. Step 710 provides for retrieving or otherwise determining stiffness settings corresponding to the selected goal from step 704 at the incline and speed selected in step 708. In certain examples, the goals may be supplemented by a measured or estimated metabolic response for the user, for example estimated by selecting among multiple models based on the user (e.g., height, weight, age, sex, calculated fitness level), the fitness machine, and the manner in which the fitness machine is being operated. The metabolic response may also or alternatively include inputs from various sensors in a manner known in the art. Step 712 provides for adjusting the stiffness as necessary to make the actual deck deflection fall within the allowable range determined in step 710. Any adjustments to the stiffness in step 712 may further be communicated to the user in step 714. If the user is determined in step 716 to change the speed or incline of the fitness machine (and/or if the measured or estimated metabolic response changes), the process returns to step 710 to again retrieve or determine the corresponding deck deflection range allowable for that speed and incline.

[0107] FIG. 20 shows a method 800 in which historic adjustments for adjusting shock absorption become learned behavior for future shock absorption adjustments. In this case, the process begins in step 802 by determining the user’s preference of stiffness settings at different speeds and inclines based on previously logged workouts. The user’s selection is received in step 804 to operate the fitness machine using these past preferred stiffness settings from step 802. The user also selects a speed and incline settings in step 804 in a conventional manner. Step 808 provides for determining the preferred stiffness settings (from step 802) corresponding to the incline and speed selected in step 806. Step 810 provides for adjusting the stiffness as necessary to make the actual deck deflection fall within the allowable range determined in step 808. Any adjustments to the stiffness in step 810 may further be communicated to the user in step 812. If the user is determined in step 814 to change the speed or incline of the fitness machine, the process returns to step 808 to again retrieve the preferred stiffness settings from step 802 corresponding to that speed and incline.

[0108] FIG. 21 shows a method 900 for making small, minimally perceivable changes to the shock absorption during the workout, which begins upon receiving such a selection for operation in step 902. In step 904, the user selection is received for a general preference of stiffness, for example chosen from a group 906 of options that include “soft,” “medium,” “firm,” and “full range.” A user selection of speed and incline is also received in step 908 in a conventional manner. Step 910 provides for determining adjustment amounts for small or “micro” adjustments to the stiffness over time, whereby the adjustments remain within the general preference range received in step 904. The allowable range for the micro adjustments corresponding to each preference range may be stored in memory, or be within a certain absolute or relative value of a setpoint for each preference range. For example, “soft” may be assigned a deck deflection of 0.5” as the setpoint, whereby the micro adjustments are then constrained to be within ±0.1”, 0.25”, 1%, or 5% of that setpoint. The stiffness is then adjusted in step 912 according to the determination of step 910, for example changing at a periodic interval (e.g., every 1 minute) or randomly. Adjustments to the stiffness may further be communicated to the user in step 914. The process may continue until the workout is complete. The present inventors have identified that small adjustments to the shock absorption help to keep users engaged and may better correspond to running in outdoor environments where running surface stiffness can vary from one step to another. This may also serve to subtly disrupt the “repetitive” aspects of endurance gait as the exerciser makes imperceptible adjustments in response to the stiffness changes.

[0109] FIG. 22 shows a method 1000 for adjusting the shock absorption to maintain a target deck deflection, which begins upon receiving such a selection for operation in step 1002. Step 1004 provides for receiving a user selection of a preferred range of deck deflection, which may be a selection from a group 1006 of different deflection amounts. User selections of speed and incline arc also received in step 1008 in a conventional manner. Step 1010 provides for receiving sensor measurements of actual deck deflection (e.g., an average deflection over several strides) and determining whether the actual deck deflection corresponds to the preference of deflection range received in step 1004. If the actual deck deflection is determined in step 1012 to be within range, no changes are made to the stiffness. If instead the actual deck deflection is not in range in step 1012, the stiffness is correspondingly decreased (step 1016) or increased (step 1018) as needed to bring the actual deck deflection within the preferred range received in step 1002. The process may return to step 1010 on a period basis, and/or return to step 1008 if any changes are made to speed or incline.

[0110] The present inventors have recognized that adjusting shock absorption to achieve a target deck deflection (whereby this target may change based on other factors, including user selections, user weight, simulated courses, and/or other inputs described herein) may be particularly advantageous. In particular, using a target deck deflection can be used to accommodate for changes or variation in the performance of fitness machine components. For example, the resilient bodies or other components may perform differently over time (e.g., being broken in and/or the materials changing properties over time), in different climates (e.g., warmer temperatures), due to part-to-part variation, and/or due to manufacturing or maintenance variation. Likewise, wear over time may increase play between components or otherwise cause changes in the resistance provided by the resilient body at a given setting.

[0111] A similar deck deflection-based adjustment method is provided in FIG. 23, which now provides protection against exceeding a maximum deflection distance. The method 1100 begins at step 1102, whereby the fitness machine stores an expected amount of deck deflection as a function of user weight for each stiffness setting. In step 1104 a user selection of speed and incline is received in a customary manner. The method determines in step 1106 whether a softest of the stiffness setting has been selected. If the determination at step 1106 is “yes,” step 1108 provides for receiving sensor measurements of actual deck deflection (e.g., an average deflection over several strides) and determining whether the actual deck deflection exceeds a predetermined maximum deflection amount for the fitness machine stored in memory. The maximum deflection amount is chosen to prevent damage to components and/or to prevent the deck from bottoming out such that no shock absorption is provided. If the actual deck deflection is found to exceed the predetermined maximum deflection in step 1 108, the stiffness is increased in step 1 110 so as to reduce the actual deck deflection going forward. If instead the actual deck deflection docs not exceed the predetermined maximum deflection in step 1108, the stiffness is left as-is (step 1112). [0112] Returning to step 1106, if instead the softest stiffness setting has now been selected, the process continues to step 1114. In step 1114, the user’s weight is calculated based on the measured amount of actual deck deflection (see step 1108) by referencing the known relationship between deflection and body weight at a given stiffness setting as discussed above (see step 1102). If in step 1116 it is determined that the calculated body weight is at or above a body weight that would create deflection beyond the predetermined maximum deflection amount for the fitness machine is the softest stiffness setting were selected (via the logic of step 1102), the fitness machine is prevented from selecting the softest stiffness setting.

[0113] In embodiments using a measurement of the movement of the at least one member during operation of the fitness machine, discussion was provided above regarding the use of the sensor assembly 250 of FIGS. 11 and 12, as well as other types of sensors. In certain embodiments, the movement is used to calibrate the actual shock absorption being provided versus what the fitness machine expects for a given setting. In further embodiments, the movement is measured at multiple locations of the member engaged by the user (e.g., at all four comers of a treadmill deck), which are used to determine the stability of a user while running. Stability can then be improved by adjusting the stiffness at the rear and front separately (providing a combination of relative stiffness settings between landing and toe off, such as a stiff toe-off and a softer landing, and/or added support toward the rear of the running deck for a user running near the rear end of the treadmill). As discussed above, these secondary inputs may be used in conjunction with shock settings, and/or in conjunction with each other.

[0114] The system 40 may also be configured to particularly determine a position of the user or a part thereof during operation, specifically by comparing measurements of multiple sensor assemblies 250. These measurements may be deflection measurements, force measurements, imaging measurements from a vision system, or any other type of measurement by which a position of the user may be discerned. With reference to the example system 40 of FIG. 25, measurements from six sensor assemblies 250 (e.g., piezo electric sensors or deflection sensors) can be compared to determine the position in which the user’s foot contacts the member engageable between the front 21 and the back 22, and between the left 23 and the right 24 of the fitness machine 1. In other words, by comparing the measurements of the front-most, center-most, and back-most sensors, it is possible to determine whether the user is positioned between the front and center, or between the center and the back. Moreover, based on the amplitudes of these measurements, it is possible to further determine not only whether the user is positioned between the front and center, but approximately where in the length direction therebetween (e.g., twice as close to the front as to the center). The same process can be used to determine the position of the user between the left and the right, specifically using different sensors corresponding thereto. By knowing the positions of the sensors relative to the fitness machine, the overall position of the user can be determined relative to the fitness machine each time the user engages with the fitness machine, for example with every footfall.

[0115] This positional determination may be made specifically for the take-off positions of a foot, the landing positions of the foot, and/or a centered position of the user (e.g., between the take-off and landing) over time. As discussed above, the system 40 then allows for adjusting the shock adsorption independently at different regions of the member being engaged by the user, such as the running deck. For example, adjustments can then be made when the user is found to be positioned closer to the front 21 or to the back 22 than expected, or non-centered between left 23 and right 24. The system 40 not only allows adjustments to accommodate for the position of the user, but also to customize the stiffness for different phases of the exercise. In certain treadmill examples, the shock adsorption is adjusted such that the user experiences a different stiffness for taking-off than for landing, customizing the user experience for user preference, optimized performance, to minimize stress and/or prevent injuries, and/or for rehabilitation purposes.

[0116] The system 40 may also be configured to make shock absorption adjustments as the user is found to move over the course of a workout. For example, the user may initially start positioned relatively close to the front 21 of the fitness machine 1 but progressively move towards the back 22 over time, such as due to fatigue or changes in speed. In certain examples, moving averages (e.g., an average over 5 measurements or over 1 minute) and/or thresholds (e.g., aposition change of at least 6 inches) are used when comparing the user positions over time. This provides that shock absorption adjustments are not performed for transient events and/or more often than desired by the user.

[0117] In certain examples, a series of deflection sensors are provided along the deck of the treadmill, such as the sensors discussed above. The measurements provided by the deflection sensors are used by the control system to determine the deformed shape of the deck, such as by dynamically by curve fitting the deflection sensor readings and analyzing patterns in these curves. Through experimentation and development, the present inventors have recognized that a first peak is observed within the deflection measurements at the time when the first downward motion is detected in a gait cycle, which is greatest at the location of the user’s foot landing on the deck. This allows the foot fall location to be determined front to back and/or left to right, depending on the configuration of the sensors. The maximum deformation occurs at the time when the user’s foot is right under the center body mass, which is greatest at this center body mass location. This allows the centered or average location of the user to be determined. The next peak in the deck deformation curves then corresponds to the toe off location for the user, which is again greatest at the location of the toe off. In this manner, the measurements of multiple sensors can be used to identified the specific locations of engagement with the deck. This can also be monitored as an ongoing process to make dynamic adjustments to the stiffness and other parameters as discussed herein. FIG. 26 shows exemplary data collected from five deflection sensors positioned at different positions along the deck, whereby the data measured at each of the times above reveal the locations on the deck in which each engagement occurs.

[0118] FIG. 24 illustrates a further example of a method for adjusting shock absorption according to the present disclosure. As will become apparent, this method 1200 details one example for handling of stiffness adjustments autonomous. This may be particularly advantageous for users that are not sure what shock absorption selection to make and/or do not want to make such a selection. In the example shown, step 1202 provides that the user first selects an “Auto Deflection Workout” in which shock absorption will be automatically adjusted to provide a controlled amount of deck deflection, which may be provided via control of such components as those discussed above. From the perspective of the fitness machine 1, step 1202 also refers to the fitness machine receiving a selection to operate in an auto deflection workout. It should be recognized that in other embodiments, the fitness machine 1 may default to such a mode, or perform this autonomous stiffness control when a “Quick Start” exercise mode is selected. In certain examples, step 1202 further includes retrieving a stored stiffness setting that was previously used for the shock absorption, as discussed further below.

[0119] Step 1204 provides for the exerciser selecting a speed and/or incline and a workout beginning, and thus likewise the fitness machine receiving a speed and/or incline selection and operating accordingly. The present disclosure contemplates configurations in which the speed and/or incline docs not originate with the user, for example being provided by a workout program or a trainer leading a group of exercisers. Likewise, speed and incline selections can be made by inaction, for example with the fitness machine operating with previous settings or default values. [0120] In step 1206, sensors such as those described above measure the deflection of the member engageable by the user (e.g., a running deck of a treadmill). In the example step 1206 shown, these measurements are made over several strides and then averaged, whereby the average (which may be a running average) is then compared by the control system to one or more predetermined thresholds stored in the memory system. By way of example, the threshold may be a single value, or there may be multiple thresholds, such as a lower threshold (e.g., a first deck deflection distance) and a separate upper threshold (e.g., a second deck deflection distance). In an example in which the target deflection is 10 mm, an upper threshold of 12 mm and a lower threshold of 8 mm may be provide, whereby measurements outside of these upper and lower thresholds cause the system to automatically change the stiffness and/or advise the user to change the stiffness to achieve this target deflection. A similar objective may also be achieved with a single threshold of 2 mm, whereby action is taken if the measured deflection deviates from the target deflection by more than the threshold of 2 mm. It should be recognized that the present disclosure may refer to a measurement being outside or beyond a threshold to mean that the threshold has been triggered (e.g., below a lower threshold and/or above an upper threshold).

[0121] If the measured deflection (or average thereof) is determined in step 1208 to be below the lower threshold, the shock absorption is adjusted to decrease the stiffness in step 1210 to thereby increase deck deflection. As discussed above, this may be performed by controlling an actuator that changes the shock absorption provided by a resilient body such as a leaf spring.

[0122] Alternatively, if the measured deflection is determined in step 1208 to not be below the lower threshold, the method 1200 continues to step 1212. If the measured deflection is determined in step 1212 to be above the upper threshold, the shock absorption is adjusted to increase the stiffness in step 1214 to thereby decrease deck deflection. If instead the measured deflection is not above the upper threshold in step 1212, the method 1200 continues to step 1216, whereby operation continues at the current stiffness settings (i.e. , no shock absorption adjustments are made). The stiffness settings are then recorded in step 1218 to be retrieved again in the future. These stiffness settings may be saved with the user’s profile to be later retrieved upon logging in for future exercise sessions.

[0123] The present inventors have recognized that saving the stiffness setting in step 1218 advantageously provides a starting point to expedite the process of controlling shock absorption to automatically provide the desired deck deflection in the future. This may result in fewer changes by the fitness machine 1 as the user is starting up, reducing use and wear on the actuators and other components. Moreover, this prevents the exerciser from having to begin with sub-optimal stiffness setting until measurements are made and stiffness adjustments are executed.

[0124] The method 1200 also advantageously for any changes over time that require a different stiffness setting even for the same user. For example, the resilient bodies may degrade or be replaced (impacting the resistance provided thereby), the user may gain or lose weight, the user may change their gait, or other changes in the fitness machine or user may impacting deck deflection. In these cases, not only does the method 1200 provide for automatically adjusting the shock absorption accordingly, but saving the new stiffness settings in step 1218 for future use. [0125] The present inventors have identified that by controlling the shock absorption of the fitness machine as described herein, the user has an improved experience and increase realism. Likewise, the control system 200 may use trends identified in movement data to detect changes in the system over time (e.g., the wear of parts over time, the resilient member becoming more compliant), triggering a replacement of parts, or compensation in the adjustment of shock absorption settings to provide the desired results and/or prevent damage to components over time. [0126] The functional block diagrams, operational sequences, and flow diagrams provided in the Figures are representative of exemplary architectures, environments, and methodologies for performing novel aspects of the disclosure. While, for purposes of simplicity of explanation, the methodologies included herein may be in the form of a functional diagram, operational sequence, or flow diagram, and may be described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance therewith, occur in a different order and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology can alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all acts illustrated in a methodology may be required for a novel implementation. [0127] While some of the methods described above and shown in FIGS. 16-24 are detailed from the perspective of the user or exerciser using the fitness machines 1 disclosed herein, one of ordinary skill in the art would recognize that these user-focused steps also disclose steps or actions by the fitness machine 1. For example, an exerciser selecting a workout to target muscles (step 402 of FIG. 16) must also be interpreted as disclosing a fitness machine configured to perform a step of receiving such a selection of a workout to target muscles. Additionally, the examples provided throughout this disclosure shall be interpreted as non- limiting. For example, whereas step 416 of FIG. 16 provides that the exerciser changes the speed or incline (which also thereby discloses a fitness machine performing the steps of changing the speed or incline), it should be recognized that the change to the speed or incline need not originate with the user. In certain cases, such a speed or incline change may be directed by a workout program being performed by the fitness machine, or a fitness instructor leading a group, for example.

[0128] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. Certain terms have been used for brevity, clarity, and understanding. No unnecessary limitations are to be inferred therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes only and are intended to be broadly construed. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have features or structural elements that do not differ from the literal language of the claims, or if they include equivalent features or structural elements with insubstantial differences from the literal languages of the claims.

Claims

CLAIMS What is claimed is:

1. A fitness machine providing shock absorption for a user operating the fitness machine, the fitness machine comprising: a base; at least one member engageable by the user and moveable relative to the base during operation of the fitness machine; a resilient body that resists movement of the at least one member towards the base so as to provide shock absorption for the user, wherein the resistance provided by the resilient body is adjustable; and a control system configured to receive from the user a shock setting corresponding to how much shock absorption is desired, and to receive other than from the user a secondary input, wherein the control system is further configured to adjust the resistance provided by the resilient body based on the shock setting and the secondary input.

2. The fitness machine according to claim 1, wherein the secondary input is based at least in part on a target muscle group for the user when operating the fitness machine.

3. The fitness machine according to claim 1, wherein the secondary input is based at least in part on a metabolic response of the user when operating the fitness machine.

4. The fitness machine according to claim 1, wherein the secondary input is based at least in part on historical adjustments of the resilient member from previous operation of the fitness machine.

5. The fitness machine according to claim 1, wherein the secondary input is based on a program for operating the fitness machine over a period of time.

6. The fitness machine according to claim 5, wherein the program includes simulated terrains that change over the period of time for operating the fitness machine, and wherein the secondary input is based at least in part on the simulated terrains.

7. The fitness machine according to claim 5, wherein the program includes random adjustments for the resistance provided by the resilient member over time, and wherein the secondary input is based at least in part on the random adjustments in the program.

8. The fitness machine according to claim 1, further comprising a sensor that measures the movement of the at least one member towards the base during operation of the fitness machine, wherein the control system is further configured to generate a trend in the movement measured by the sensor over time, wherein the secondary input is based at least in part on the trend generated from the movement measured by the sensor.

9. The fitness machine according to claim 1, further comprising a sensor that measures the movement of the at least one member towards the base during operation of the fitness machine, wherein the control system is further configured to determine a position of a foot of the user on the at least one member engageable by the user, and wherein the secondary input is based at least in part on the position of the foot determined by the control system.

10. The fitness machine according to claim 9, wherein the position includes both a take-off position and a landing position for the foot.

11. The fitnes s machine according to claim 1 , wherein the resilient body is two or more resilient bodies that each resist movement of the at least one member towards the base, and wherein the control system is configured to adjust the resistances provided by two or more resilient bodies independently of each other based on the shock setting and the secondary input.

12. The fitness machine according to claim 11, further comprising a sensor that measures the movement of the at least one member towards the base during operation of the fitness machine, wherein the control system is further configured to determine a position of a foot of the user on the at least one member engageable by the user, and wherein the secondary input for independently adjusting the two or more resilient bodies is based at least in part on the position of the foot determined by the control system.

13. A method for making a fitness machine providing shock absorption for a user operating the fitness machine, the method comprising: providing a base and at least one member engageable by the user and moveable relative to the base during operation of the fitness machine; providing a resilient body that resists movement of the at least one member towards the base so as to provide shock absorption for the user, wherein the resistance provided by the resilient body is adjustable; configuring a control system to receive from the user a shock setting corresponding to how much shock absorption is desired, and to receive other than from the user a secondary input; and adjusting the resistance provided by the resilient body based on the shock setting and the secondary input.

14. The method according to claim 13, further comprising adjusting the resistance based on at least one of a target muscle group for the user and a metabolic response of the user when operating the fitness machine.

15. The method according to claim 13, further comprising adjusting the resistance based at least in part on historical adjustments of the resilient member from previous operation of the fitness machine.

16. The method according to claim 13, further comprising adjusting the resistance based at least in part on a program for operating the fitness machine over a period of time.

17. The method according to claim 13, further comprising measuring a movement of the at least one member towards the base during operation of the fitness machine, generating a trend of the movement over time, and adjusting the resistance based at least in part on the trend.

18. The method according to claim 13, wherein the resilient body is two or more resilient bodies that each resist movement of the at least one member towards the base, and wherein the resistances of the two or more resilient bodies are adjusted independently based on the shock setting and the secondary input.

19. The method according to claim 18, further comprising determining a position of a foot of the user on the at least one member cngagcablc by the user, wherein the secondary input is based at least in part on the position of the foot determined by the control system.

20. A method for making a fitness machine providing shock absorption for a user operating the fitness machine, the method comprising: providing a base and at least one member engageable by the user and moveable relative to the base during operation of the fitness machine; providing a resilient body that resists movement of the at least one member towards the base to provide shock absorption for the user; adjusting the resistance provided by the resilient body based on a previous resistance from a previous operation of the fitness machine; measuring the movement of the at least one member during operation of the fitness machine; determining whether the movement of the at least one member is beyond a threshold; further adjusting the resistance provided by the resilient body when the movement is determined to be beyond the threshold; and storing the resistance provided by the resilient body as the previous resistance for future operation of the fitness machine.