| 摘要 |
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.
|
