i think it mostly comes down to what your body is already used to. ie: if you are used to a sport it should be fine, but dont take up anything new that is strenuous. also, with things like tennis, i think the fact that your ligaments are stretching, can mean you can twist your ankle more easily. just take it easy and make sure you dont overheat. overall, i think there seems to be a lot of varied messages about this, just listen to your body,

Linda