Originally Posted by
sprince
Mostly true. But stretching is critical if you want to increase power, and increased power will allow creating more tension in the muscles, which can help to increase muscle size. And cycling, just like sitting all day at a desk, shortens the hamstrings which can cause other problems. I think the real magic of stretching is that it increases strength through the entire range of motion which has benefits for both strength and endurance. Also note that increased flexibility reduces the amount of work required to overcome inflexibility. So for cycling that means the quads don't have to work as hard to overcome hamstring tension.
There is nothing you can do sitting on a bike that amounts to effective stretching.
Stretching doesn't increase flexibility in a muscle. Innervating a muscle adds flexibility to a muscle. It's best to do correct weight lifting movements if you want to gain more flexibility in a muscle. The only power to be gained is to be able to utilize more muscle tissue. There is a reflex associated with stretching that some try to utilize while lifting to maximize the contraction, but the point of that is that the body has a natural stop with that reflex response. Too many people think they can get a benefit from no work, and just try to over-extend their joints or tear muscles and tendons and ligaments. It's all unnecessary and doesn't provide real results in a way that makes sense or achieves progressive results on an ongoing basis.