| 摘要 |
<p>A variable resistance device and an abdominal exercise apparatus. The device includes at least first and second resilient stages to provide a combined resistance effect. The first resilient stage has a lower coefficient of elasticity than the second resilient stage. In this way, when a user lies on the base of the apparatus and pulls on the yoke a first resistance is experienced by virtue of thin cords until a strap reaches its full length and a second resistance is experienced by virtue of thick cords.</p> |
