in exercise, is it really true that "no pain, no gain"?

<p>I’m on a meal plan lol … one thing my dining halls don’t have too often is fish (except tuna salad), which would be one of the foods with the highest protein-per-calorie ratios, I suppose?</p>

<p>And I really dislike running, though I like walking – it’s just the impact against the tarmac that bothers me. But swimming is like wheeeeeee!</p>