August Krogh

The most direct evidence of the wonderful plasticity and elasticity of red corpuscles is obtained when they are watched in a current, where they can be caught against a projecting edge and bent by the pressure of the current flowing past them.

Flexibility is crucial to my fitness. Incorporating a good warm-up and cool-down into every session decreases my chances of injury. I use both dynamic and static stretching in my training. I've starting doing a few yoga sessions which incorporates muscle strength and flexibility.