Exercise device

Abstract

An exercise device comprising a stretchable elongated element comprising a pair of coaxial stretchable elongated elements, including an inner stretchable elongated element and an outer stretchable elongated element. The outer stretchable elongated element comprising a stretchable elongated tube having a length and defining a channel extending substantially along the entire length of the stretchable elongated tube. The inner stretchable elongated element is received by the channel and extends substantially along the entire length of the stretchable elongated tube The inner stretchable elongated element may also comprise a stretchable elongated tube. The outer stretchable elongated element and the inner stretchable elongated element may have different tensile strengths and may have different moduli of elasticity.

Description

BACKGROUND

Resistance exercise devices compromising a stretchable elongated tube for providing resistance exercise and building muscle tone are known in the art. For example, U.S. Pat. No. 5,800,322, which is incorporated herein by reference, discloses such a resistance exercise device that also includes a handle on each end of the stretchable elongated tube. A user of the device grasps the handles and repeatedly pulls or stretches the stretchable elongated tube and then slowly releases the stretchable elongated tube to provide resistance exercise. There are other known exercise devices that include one or more stretchable elongated tubes and many different forms of resistance exercise.

SUMMMARY

The present disclosure relates to an exercise device comprising a stretchable elongated member comprising a pair of coaxial stretchable elongated, including an inner stretchable elongated element and an outer stretchable elongated element. The exercise device may further include an exercise engaging structure, such as, for example, one or more handles, grips, body engaging members or the like. The outer stretchable elongated element comprises a stretchable elongated tube having a length and defining a channel extending substantially along the entire length of the stretchable elongated tube. The inner stretchable elongated element is received by the channel and extends substantially along the entire length of the stretchable elongated tube. The inner stretchable elongated element may also comprise a stretchable elongated tube. The outer stretchable elongated element and the inner stretchable elongated element may have different tensile strengths and may have different moduli of elasticity.

Features and advantages of the disclosure will be set forth in part in the description which follows and the accompanying drawings described below, wherein an embodiment of the disclosure is described and shown, and in part will become apparent upon examination of the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention and the advantages thereof will become more apparent upon consideration of the following detailed description when taken in conjunction with the accompanying drawings:

FIG. 1 is a perspective view of an exercise device in accordance with an embodiment of the present disclosure, including a cut-away portion to illustrate the inner stretchable elongated element coaxial to the outer stretchable elongated element;

FIG. 2 is a cross section taken along the lines 2-2 of FIG. 1;

FIG. 3 is a perspective view of an exercise device in accordance with another embodiment of the present disclosure, including a cut-away portion to illustrate the inner stretchable elongated elements coaxial to the outer stretchable elongated element;

FIG. 4 is a perspective view of an exercise device in accordance with another embodiment of the present disclosure, including a cut-away portion to illustrate the inner stretchable elongated elements coaxial to the outer stretchable elongated element;

FIG. 5 is a cross section and partial view of a pair of coaxial stretchable elongated elements in accordance with another embodiment of the present disclosure.

FIG. 6A is a simplified illustration of an embodiment of an exercise device in accordance with the present disclosure.

FIGS. 6B-6F are simplified perspective cross section partial illustrations of further configurations of exercise devices in accordance with the present disclosure.

DETAILED DESCRIPTION

FIGS. 1-2 provide an example of an exercise device 10 in accordance with an illustrated embodiment of the present disclosure. The illustrated exercise device 10 comprises a stretchable elongated member 12 including multiple stretchable elongated elements and exercise engaging structure including a pair of handles 18. As will be more fully described below, numerous configurations or arrangements of the multiple stretchable elongated elements are contemplated. In the embodiment illustrated in FIGS. 1-2, the multiple stretchable elongated elements are in the form of an outer stretchable elongated tube 14 and an inner stretchable elongated tube 16 extending the entire length of the outer stretchable elongated tube. The outer stretchable elongated tube 14 is disposed about the inner stretchable elongated tube 16. In an embodiment, the outer stretchable elongated tube 14 is formed on an outer surface of the inner stretchable elongated tube 16. The outer and the inner stretchable elongated tubes 14 and 16 define respective channels 24 and 26 along their respective lengths. The inner stretchable elongated tube 16 is received by the channel 24 of the outer stretchable elongated tube 14 along the length of the outer stretchable elongated tube. The outer and inner stretchable elongated tubes 14 and 16 each define a pair of open ends 30 and 32, respectively, and together define a pair of joint open ends 34. The handles 18 are secured to the joint ends 34. The outer and inner stretchable elongated tubes 14 and 16 each may be in the form of commercially-available rubber latex tubing that also has been referred to as exercise tubing, fitness tubing, surgical tubing, dipped tubing, gum rubber tubing, etc. Such tubing is typically available in different diameters, depending upon the desired resistance.

Because of its multiple element construction, the stretchable elongated member 12 provides several advantages. For example, if the outer stretchable elongated tube 14 breaks, the inner stretchable elongated tube 16 keeps the exercise device 10 intact; or, conversely, if the inner stretchable elongated tube 16 breaks, the outer stretchable elongated tube 14 keeps the exercise device 10 intact. Additionally, the outer stretchable elongated tube 14 protects the inner stretchable elongated tube 16 from conditions that might otherwise cause breakage or other failure of the inner stretchable elongated tube. For example, depending upon the form of exercise, the outer stretchable elongated tube 14 may come in contact with an abrasive or sharp surface, including for example, a rail, bar, support shoe or other surface. Under such circumstances, the outer stretchable elongated tube 14 protects the inner stretchable elongated tube 16 from contact with such surface and thereby reduces the chances that the inner stretchable elongated tube will break or otherwise fail. The outer stretchable elongated tube 14 also protects the inner stretchable elongated tube 16 from any other environment conditions.

The outer and inner stretchable elongated tubes 14 and 16 may also have different tensile strengths or may have different moduli of elasticity, providing further advantages depending upon the construction of the stretchable elongated member 12. For example, the outer and inner diameters of the outer stretchable elongated tube 14 are greater than the outer and inner diameters of the inner stretchable elongated tube and the cross sectional surface area of the outer stretchable elongated tube 14 therefore may be greater than the cross sectional surface area of the inner stretchable elongated tube 16. As a result, assuming that the outer and inner stretchable flexible tubes 14 and 16 are constructed of the same material, the tensile strengths and moduli of elasticity of the inner and outer stretchable elongated tubes 14 and 16 are different. Further, the tensile strength and modulus of elasticity can be modified by using a different outer stretchable elongated tube 14 or a different inner stretchable elongated tube 16 having different outer and inner diameters. The magnitudes of the tensile strengths and moduli of elasticity for each of the outer and inner stretchable elongated tubes 14 and 16 may be consistent with that of the commercially-available rubber latex tubing or may have any other suitable magnitudes. Further, because the choice of material of each of the outer and inner stretchable elongated tubes 14 and 16 affects the tensile strength and modulus of elasticity of each tube, the relative tensile strength and moduli of elasticity of each of the outer stretchable elongated tube 14 and the inner stretchable elongated tube 16 can be modified by using an outer or inner stretchable elongated tube constructed of any other material.

If the tensile strengths of the outer and inner stretchable elongated tubes 14 and 16 are different, and assuming the outer and inner stretchable elongated tubes 14 and 16 are otherwise in good condition, the tube 14 or 16 having the weaker tensile strength will break first in response to a tensile force of sufficient magnitude. Thus, upon failure or breakage of one of the outer or inner stretchable elongated tubes 14 or 16, the other tube will sustain the tensile load without failure or breakage and keep the exercise device 10 intact. Further, if the moduli of elasticity of the outer and inner stretchable elongated tubes 14 and 16 are different, the resistance of the stretchable elongated member 12 will be based on the tube having the lower modulus of elasticity.

The handles 18 of the exercise device 10 illustrated in FIGS. 1-2 may be secured to the stretchable elongated member as described in U.S. Pat. No. 5,800,322, which is incorporated herein by reference, and may be constructed as described in U.S. Pat. No. 5,800,322. Thus, the exercise device 10 may further include a pair of plugs 40 and a pair of sleeves 42 for securing the handles 18 to the stretchable elongated member 12 adjacent respective joint open ends 34 of the stretchable elongated member. The exercise device 10 may further include a grommet 48 on each handle 18 and a hand grip 50 disposed about each handle 18. The handles 18 may be secured to the stretchable elongated member 12 in any other manner and may be constructed in any other manner in accordance with other embodiments of the present disclosure.

The exercise device 10 in accordance with the present disclosure may instead be in any other suitable form that includes a stretchable elongated tube or other member.

The exercise device may, for example, be in the form of the exercise attachments described in U.S. patent application Ser. No. 11/342,935, which is incorporated herein by reference.

The stretchable elongated member in accordance with the present disclosure can also be incorporated in any commercially-available resistance exercise product.

FIG. 3, for example, shows an exercise device 110 having a stretchable elongated member 112 in accordance with another embodiment of the present disclosure. The stretchable elongated member 112 forms a loop and includes an outer stretchable elongated tube 114 and a coaxial inner stretchable elongated tube 116 extending the entire length of the outer stretchable elongated tube, and exercise engaging structure including a pair of body engaging members 118. The outer stretchable elongated tube 114 is disposed about the inner stretchable elongated tube 116. The outer stretchable elongated tube 114 defines a channel 124 along its length. The inner stretchable elongated tube 116 is received by the channel 124 of the outer stretchable elongated tube 114. The inner stretchable elongated tube 116 also defines a channel along its entire length (not shown). The body engaging members 118 may have any suitable construction and may be engaged with the stretchable elongated element 112 in any suitable manner. U.S. patent application Ser. No. 10/774,719, filed Feb. 9, 2004, which is incorporated herein by reference, provides examples of possible constructions of the body engaging members 118 and manners of engaging the body engaging member 118 with a stretchable elongated member 112.

FIG. 4 illustrated an exercise device 210 having a stretchable elongated member 212 in accordance with the present disclosure. The stretchable elongated member 212 forms a pair of loops and has a “FIG. 8” configuration. The stretchable elongated member 212 includes an outer stretchable elongated tube 214 and an inner stretchable elongated tube 216 extending the entire length of the outer stretchable elongated tube, exercise engaging structure including a pair of grips 218 disposed on each loop about the stretchable elongated member 212, and a coupling member 260. The outer stretchable elongated tube 214 is disposed about the inner stretchable elongated tube 216. The outer stretchable elongated tube 214 defines a channel 224 along its length. The inner stretchable elongated tube 216 is received by the channel 224 of the outer stretchable elongated tube 214. The inner stretchable elongated tube 216 also defines a channel along its entire length (not shown).

The exercise device in accordance with the present disclosure may be in any other form and includes the stretchable elongated member described herein and any other exercise engaging structure configured to engage any part of the limbs or body or that is configured to engage any structure. The exercise device can even be in the form of a single strip of the stretchable elongated member described herein without any associated structure.

The stretchable elongated member in accordance with the present disclosure may include more than one inner stretchable elongated element. It may, for example, include a plurality of inner stretchable elongated tubes that are coaxial to the outer stretchable elongated tube. The plurality of tubes may form a plurality of layers, wherein an outer layer is formed on an immediately radially inner layer. Further, FIG. 5 illustrates an embodiment of the present disclosure wherein the stretchable elongated member 312 includes an outer stretchable elongated tube 314 disposed about a solid core 316 (rather than an inner stretchable elongated tube) of a material of a higher or lower tensile strength and a higher or lower modulus of elasticity than the outer stretchable elongated tube 314. The solid core 316 forms a separate form of an elongated stretchable element.

The solid core 316 is coaxial to and extends substantially along the length of the outer stretchable elongated tube 314 within the channel 324 defined by the outer stretchable elongated tube. The solid core 316 substantially fills the inner channel of the outer stretchable elongated tube 314 and has a cross section that is substantially equal to the cross section of the outer stretchable elongated tube 314. Still further, any combination of tubes and the solid core may also be included in accordance with other embodiments.

Turning to FIG. 6A, in one embodiment of the present invention, the stretchable elongated member 1020, comprises elastic or rubber or otherwise flexible stretchable elongated elements in the form of bands or tubes that provide varying levels of resistance. For example, the stretchable elongated member 1020 may include latex bands, non-latex bands, rubberized bands, rubber tubing, or other types of flexible exercise bands or devices.

For example, the stretchable elongated member 1020 may include THERABAND brand products by Lifestyle Sports, Inc. or Dunkirk, N.Y. or SPRI brand products by SPRI Products, Inc. of Libertyville, Ill., or others. However, the stretchable elongated members of the disclosure are not limited to THERABAND brand or SPRI brand products and bands or tubes by other manufacturers can also be used. In addition, the present invention is not limited to elastic or rubber bands or tubes. Flexible tubes of other materials can also be used.

In one embodiment, the stretchable elongated member 1020 includes elements of a higher modulus material attached to and covered, in whole or in part, by covering of a an element having a lower modulus material, or visa-versa. The stretchable elongated member 1020 made of elongated stretchable elements of different modulus materials prevents the stretchable elongated member 1020 from separating and causing injury to an exerciser applying the load or other exercisers or bystanders in the immediate vicinity should an element of the stretchable elongated member 1020 fail.

As is known in the art, when a material is subjected to an external load it becomes distorted or strained. When the load is removed, the material returns to its original dimensions (i.e., they are elastic). Within the limits of elasticity, the ratio of the linear stress to the linear strain is termed the “modulus” of elasticity. The higher a modulus of a material, the more stiff it is and the less flexible it is.

The stretchable elongated member 1020 is continuously stretched by a user providing resistance exercise to the user thereby alternatively applying a load to the stretchable elongated member 1020 and removing the load applied to the stretchable elongated member 1020.

In one embodiment, the higher modulus element or layer of material provides resistance and a pre-determined amount of elasticity for exercisers. The higher modulus element or layer of material is stiff yet does provide elasticity. The lower modulus element or layer of material is not stiff and provides about three to four times more elasticity than the higher modulus material and may provide very little resistance (i.e., little or no noticeable resistance for an exerciser).

For example, the lower modulus material may include a resistance and elasticity similar to that of a normal rubber band, while the higher modulus material may include a resistance and elasticity similar that of a bungy chord or rubber tube. However, the present invention is not limited to a lower modulus material that has three to four times the elasticity of the higher modulus material and other ratios of elasticity between the high and low modulus materials can also be used to practice the invention.

If the higher modulus material should wear out and fail (i.e., break), the lower modulus material covering will prevent the higher modulus material from separating and causing injury to the exerciser applying the load or other exercisers or bystanders in the immediate vicinity.

The stretchable elongated member 1020 with higher modulus and lower modulus materials may be solid, hollow or include plural types of coverings or elements as is explained below.

The stretchable elongated member 1020 may be manufactured via multiple (e.g., dual/triple) extrusions to create flexible bands, tubes, chords, cables, etc. for exercise.

In one exemplary embodiment, the stretchable elongated member 1020 comprises a higher modulus natural latex rubber core with a lower modulus natural latex rubber covering.

FIGS. 6B-F are simplified illustrations illustrating additional details of additional embodiments of stretchable elongated members in accordance with this disclosure.

FIG. 6B is a simplified illustrations illustrating a perspective and cross-sectional view of an stretchable elongated member 1087 with a solid core. The stretchable elongated member 1087 includes a stretchable elongated element being a solid core 1089 of a higher modulus material forming a first inner layer of material attached to and covered by another stretchable elongated element being a covering 1091 of a lower modulus material forming a second outer layer of material (or visa-versa, i.e., a lower modulus material covered by a higher modulus material, etc.).

In such an embodiment, the stretchable elongated member 1087 provides a pre-determined resistance and elasticity due to the solid core 1089 of the higher modulus material. If the solid core 1089 of the higher modulus material should fail (i.e., break), the covering 1091 of a lower modulus material prevents separation and injury. Should a failure occur with the solid core 1089 of the higher modulus material, the stretchable elongated member 1087 will go “limp” since the covering 1091 of the lower modulus material may have an elasticity three to four times higher than the solid core 1089 of the higher modulus material. A limp stretchable elongated member can then be replaced when noticed by the exerciser.

FIG. 6C is an additional simplified illustration illustrating a perspective view of another embodiment of a stretchable elongated member 1093 with a hollow core. The stretchable elongated member 1093 includes a hollow tube with plural layers, including but not limited to a first inner layer 1095 of a higher modulus material attached to and covered by a second outer layer 1097 of a lower modulus material (or visa versa).

The stretchable elongated member 1093 of FIG. 6C is illustrated with two layers of material.

However, the present invention is not limited to this embodiment and more layers can also be used to practice embodiments of the invention.

FIG. 6D is a simplified illustration illustrating a perspective view of another stretchable elongated member 1099. The stretchable elongated member 1099 includes a first portion 1101 of a higher modulus material. The stretchable elongated member 1099 includes a second portion 1103 comprising plural strands of a lower modulus material (or visa versa).

In one embodiment, the first portion 1101 is a solid band. In another embodiment, the first portion 1101 is a hollow tube (illustrated).

In one embodiment, the second portion 1103 includes plural strands attached longitudinally to the first portion at pre-determined angles (e.g., 90, 180 and 270 degree angles) with a pre-determined equal spacing (e.g., 90 degrees, etc.) around the first portions 1101. However, the present invention is not limited to the degree placement illustrated and the plural strands can be placed at other angles to practice embodiments of the invention.

In another embodiment, the second portion 1103 includes plural strands attached longitudinally to the first portion 1101 at various angles where the angles are separated by unequal spacing. In another embodiment, the second portion 1103 is applied in a spiral or corkscrew manner to the first portion 1101.

FIG. 6E is a simplified illustration illustrating a perspective view of another embodiment of a stretchable elongated member 1105. The stretchable elongated member 1105 includes a first portion 1107 of a higher modulus material and a second portion 1109 and a third portion 1111 of a lower modulus material. In one embodiment, the third portion 1111 is identical to the lower modulus material of the second portion 1109. In another embodiment, the third portion 1111 includes a lower modulus material different from the second portion 1109.

In one embodiment, the first portion 1107 is a solid band forming a solid core. In another embodiment, the first portion 1107 is a hollow tube (illustrated).

The stretchable elongated member 1105 includes a second portion 1109 with plural circumferential attachments adhered to and in contact with the first portion 1107 of the higher modulus material attached in a pre-determined pattern to the higher modulus material. The plural circumferential attachments of the second portion 1109 are attached with the third portion 1111 comprising one or more bands or tubes of a lower modulus material. The second portion 1109 and the third portion 1111 prevent separation of the first portion 1107, should the first portion 1107 break during application and removal of loads.

In one embodiment, the second portion 1109 includes plural circumferential attachments comprising natural or artificial rubbers or plastics. The third portion 1111 is a lower modulus material with the same modulus or a different modulus than the second portion 1109 comprising plural longitudinal bands. However, the present invention is not limited to such an embodiment and other materials and other orientations can also be used to practice the inventions (e.g., composite materials, etc.).

FIG. 6F is a simplified illustration illustrating a perspective view of another embodiment of a stretchable elongated member 1113 with additional attachments. The stretchable elongated member 1113 includes a first portion 1115 of a higher modulus material and a second portion 1117 comprising plural strands of a lower modulus material (or visa-versa).

In one embodiment, the first portion 1115 is a solid band. In another embodiment, the first portion 1115 is a hollow tube (illustrated).

In one embodiment, the pre-determined pattern includes plural strands of the second portion 1117 of lower modulus material attached circumferentially around the first portion 1115. However, the present invention is not limited to these embodiments and other combinations thereof can also be used to practice the invention.

However, the present invention is not limited to these embodiments and more or fewer strands or other attachments can also be used to practice the invention.

As described herein, an exerciser periodically applies and removes a load to embodiments of the stretchable elongated member. If the higher modulus material of the stretchable elongated member should wear out and fail (i.e., break), the lower modulus materials will prevent the higher modulus material from separating and causing injury to the exerciser, other exercisers or bystanders in the immediate vicinity.

While embodiments have been illustrated and described in the drawings and foregoing description, such illustrations and descriptions are considered to be exemplary and not restrictive in character, it being understood that only illustrative embodiments have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected. The description and figures are intended as illustrations of embodiments of the disclosure, and are not intended to be construed as having or implying limitation of the disclosure to those embodiments. There are a plurality of advantages of the present disclosure arising from various features set forth in the description. It will be noted that alternative embodiments of the disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations of the disclosure and associated methods, without undue experimentation, that incorporate one or more of the features of the disclosure and fall within the spirit and scope of the present disclosure and the appended claims.

Claims

1. An exercise device comprising a stretchable elongated member comprising a pair of coaxial stretchable elongated elements, including an inner stretchable elongated element and an outer stretchable elongated element, the outer stretchable elongated element comprising a first stretchable elongated tube having a length and defining a channel extending substantially along the entire length of the first stretchable elongated tube, the inner stretchable elongated element received by the channel and extending substantially along the entire length of the first stretchable elongated tube.

2. The exercise device of claim 1 wherein the inner stretchable elongated element comprises a second stretchable elongated tube.

3. The exercise device of claim 1 wherein the modulus of elasticity of the first stretchable elongated tube is different than the modulus of elasticity of the inner stretchable elongated element.

4. The exercise device of claim 1 wherein the tensile strength of the first stretchable elongated tube is different than the tensile strength of the inner stretchable elongated element.

5. The exercise device of claim 1 wherein the modulus of elasticity of the first stretchable elongated tube is greater than the modulus of elasticity of the inner stretchable elongated element.

6. The exercise device of claim 1 wherein the modulus of elasticity of the first stretchable elongated tube is less than the modulus of elasticity of the inner stretchable elongated element.

7. The exercise device of claim 1 wherein the tensile strength of the first stretchable elongated tube is greater than the tensile strength of the inner stretchable elongated element.

8. The exercise device of claim 1 wherein the tensile strength of the first stretchable elongated tube is less than the modulus of elasticity of the inner stretchable elongated element.

9. The exercise device of claim 1 further comprising an exercise engaging structure.

10. The exercise device of claim 9 wherein the exercise engaging structure comprises a handle and wherein the first stretchable elongated tube and the stretchable elongated element have a joint end, the handle being secured to the joint end.

11. The exercise device of claim 9 wherein the exercise engaging structure comprises a pair of handles and wherein the first and second stretchable elongated tubes have a pair of joint ends, each handle secured to a respective joint end.

12. The exercise device of claim 1 wherein the stretchable elongated member forms a loop.

13. The exercise device of claim 12 further comprising an exercise engaging structure including at least one body engaging member secured to the stretchable elongated member.

14. The exercise device of claim 1 wherein the stretchable elongated member forms two loops.

15. The exercise device of claim 14 further comprising an exercise engaging structure including a pair of grips disposed about the stretchable elongated member, one grip associated with each of the loops.

16. An exercise device comprising a stretchable elongated member comprising a pair of coaxial stretchable elongated tubes, including an inner stretchable elongated tube and an outer stretchable elongated tube, the inner stretchable elongated tube having a length and a channel extending substantially along the entire length of the outer stretchable elongated tube, the inner stretchable elongated tube received by the channel and extending substantially along the entire length of the outer stretchable elongated tube.

17. The exercise device of claim 16 wherein the modulus of elasticity of the outer stretchable elongated tube is different than the modulus of elasticity of the inner stretchable elongated tube.

18. The exercise device of claim 16 wherein the tensile strength of the outer stretchable elongated tube is different than the tensile strength of the inner stretchable elongated tube.

19. The exercise device of claim 16 wherein the modulus of elasticity of the outer stretchable elongated tube is greater than the modulus of elasticity of the inner stretchable elongated tube.

20. The exercise device of claim 16 wherein the modulus of elasticity of the outer stretchable elongated tube is less than the modulus of elasticity of the inner stretchable elongated tube.

21. The exercise device of claim 16 wherein the tensile strength of the outer stretchable elongated tube is greater than the tensile strength of the inner stretchable elongated tube.

22. The exercise device of claim 16 wherein the tensile strength of the outer stretchable elongated tube is less than the modulus of elasticity of the inner stretchable elongated tube.

23. The exercise device of claim 16 further comprising a handle and wherein the first and second stretchable elongated tubes have a joint end, the handle being secured to the joint end.

24. The exercise device of claim 16 wherein the stretchable elongated member forms a loop.

25. The exercise device of claim 24 further comprising at least one body engaging member secured to the stretchable elongated member.

26. The exercise device of claim 16 wherein the stretchable elongated member forms a pair of loops in the form of a “FIG. 8”.

27. The exercise device of claim 26 further comprising a pair of grips disposed about the stretchable elongated member, one grip associated with each loop.

28. A resistance member for use in or as an exercise device comprising: a plurality of layers of material including at least a first layer of material and a second layer of material surrounding the first layer of material, the second layer of material having an inner diameter substantially equal to an outer diameter of the first layer of material; and wherein at least two of the plurality of layers of material are formed by first and second stretchable elongated elements.

29. The resistance member of claim 28, wherein the first and second layers of material are formed by the first and second stretchable elongated elements, respectively.

30. The resistance member of claim 29, wherein a second stretchable elongated element has a length and defines an internal channel extending substantially along the entire length of the second stretchable elongated element, the first stretchable elongated element being internal to the channel and extending substantially along the entire length of the second stretchable elongated element.

31. The resistance member of claim 30, wherein the first stretchable elongated element substantially fills a cross-sectional area of the channel of the second stretchable elongated element forming a substantially solid core.

32. The resistance member of claim 28, wherein the second layer of material is substantially formed on the first layer of material.

33. The resistance member of claim 28, wherein the second layer of material is interposed between the stretchable elongated elements.

34. The resistance member of claim 33, wherein the second layer of material is a third stretchable elongated element formed on an outer surface of the first stretchable elongated element, and the second stretchable elongated element is formed on an outer surface of the third stretchable elongated element.

35. The resistance member of claim 33, wherein the third layer of material is a different material than a material of the first and second stretchable elongated elements.

36. The resistance member of claim 28, wherein all of the plurality of layers of material are formed from tubing.

37. The resistance member of claim 28, wherein the first stretchable elongated element has a different modulus of elasticity than the second stretchable elongated element.