I'm hoping someone can answer a question to which I've never heard a really satisfactory answer: Why does human health benefit from exercise whereas any kind of simple machine wears out with exercise? For example, doing a hundred stretches per day improves my health whereas stretching an elastic band 100 times per day will cause it to lose elasticity and soon destroy it. So what's the low-level mechanism by which exercise improves health in people but not in simple machines?
I'm hoping someone can answer a question to which I've never heard a really satisfactory answer: Why does human health benefit from exercise whereas any kind of simple machine wears out with exercise? For example, doing a hundred stretches per day improves my health whereas stretching an elastic band 100 times per day will cause it to lose elasticity and soon destroy it. So what's the low-level mechanism by which exercise improves health in people but not in simple machines?