Bicycle (Health)

Bicycles are often used by people seeking to improve their fitness and cardiovascular health. In this regard, cycling is especially helpful for those with arthritis of the lower limbs and are unable to pursue sports that cause impact to the knees and other joints. Since cycling can be used for the practical purpose of transportation, there can be less need for self-discipline to exercise. Interestingly, it has been found that despite toning the leg muscles, cycling actually causes buttocks to lose tone and muscle.

Cycling while seated is a relatively non-weight bearing exercise that, like swimming, does little to promote bone density. Cycling up and out of the saddle, on the other hand, does a better job by transferring more of the rider's body weight to the legs. However, excessive cycling while standing can cause knee damage. It used to be thought that cycling while standing was less energy efficient, but recent research has proven this not to be true. Other than air resistance, there is no wasted energy from cycling while standing if it's done well.

Cycling on a stationary cycle is frequently advocated as a suitable exercise for rehabilitation particularly for lower limb injury due to the low impact that it has on the joints. In particular cycling is commonly used within knee rehabilitation programs.

Excessive saddle height can cause posterior knee pain, while setting the saddle too low can cause pain in the anterior of the knee. An incorrectly fitted saddle may eventually lead to muscle imbalance. A 25 to 35 degree knee angle is recommended to avoid an overuse injury.

http://en.wikipedia.org/wiki/Cycling