Each one pound lost during a workout should be replaced with 2 cups of fluid. If the water you lose through sweat is not replaced, blood volume decreases. In the milder forms of heat illness, dizziness or fainting may occur. If you continue to exercise unaware of the symptoms, the sweating mechanism can shut down. If this happens, normal body temperature will rise.
Heat stroke can follow.
S Myths about drinking water during training or competition are rampant. It has been proven that consuming fluid, even in large amounts, prior to and during activity, has NO adverse effects upon performance and can actually improve performance. S Water is the life-blood of an athlete. Keep it flowing for the best performance. The importance of water cannot be overstated.