August Krogh

It is no doubt technically possible to study metabolism and respiration of fishes during swimming at a constant rate, and of certain insects and birds during flight, and to obtain information similar to that obtained on man during work on a bicycle ergometer or a treadmill.

The circulatory system of man and the vertebrate animals can be considered as made up of a small number of organs or subordinate systems, which are easy to recognize anatomically, and the functions of which are on the whole quite distinct.

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.