's easy to lose track of your water intake and if you're in a hot climate you'll be sweating even when you're doing nothing. Stay hydrated, and conserve your energy and glycogen stores by drinking fluids that contain electrolytes and natural sugars

but it can also cause lack of energy and motivation, dehydration, interrupted sleep, digestion problems, disrupted bowel activity, headaches, irritability, irrational anger, loss of concentration, lack of alertness and disorientation - not what you want a few

, respiratory, muscular, nervous systems and energy metabolism, all of which are promoted by a rise in temperature. It's probably no surprise to learn that a study of 25 experienced swimmers confirmed the effects of fluctuating body temperatures. The swimmers