Exercise pretty consistently makes me feel better, except if I sprain my knee (not fun!) When I can't do anything, if I can summon even the tiniest bit of motivation, I go for a walk and I more likely to be able to get things done afterwards. I would go as far as to say that it does make me hyper, but it's a good hyper. I make it a point not to exercise before bed though, because it keeps me awake.