Yeah, sometimes novel phenomena are stumbled upon. Where they are deliberately stumbled upon I would call it <i>exploration</i> rather than science.<p>I don't think that exercise falls into that category. There is nothing surprising about exercise per se.<p>Popper once challenged an audience to go out and 'observe'; I think the point of his joke was that without knowing what you're trying to observe and why then the instruction is absurd.<p>In order to claim that 'more exercise is good' you need to start by guessing why <i>some</i> exercise might be good, whilst being open to the possibility that it may not be, and then start testing the best guesses. Otherwise you literally won't be able to interpret your 'more exercise' data, even if it is relevant.