When you exercise, you may sweat more than usual to regulate your body temperature. Sweat is mostly water, and because water is heavy, you may lose some of your body weight as you exercise. If you weigh yourself before and after you exercise, you may have lost several pounds, but this water weight loss is only temporary. Talk to your doctor before starting a new exercise program if you have health conditions or injuries.
Sweating After Exercise
It's natural to lose water weight when you exercise or you're exposed to hot temperatures. Weighing yourself immediately after you exercise does not provide an accurate number. The scale will say you lost weight, but it is really water weight. When you drink liquids after your workout, your body absorbs the water and you return to your normal weight.
Some fad diet programs recommend wearing trash bags or layers of sweatshirts while exercising to lose more water weight. The body will get hotter than it usually does, which will make you sweat more than usual. Not only is this weight-loss method ineffective, but it could also be dangerous. Excessive sweating may cause dehydration, which in turn may cause dizziness, headache and confusion -- and it could be fatal if it's left untreated.
Why Rehydration Is Essential
After you exercise, it is imperative that you replenish the water and electrolytes that you lost by sweating. Although this means you gain the weight back that you lost, it helps your muscles heal and prevents dehydration. Water may also suppress the appetite and keep your body from retaining excess water. Drinking at least eight glasses of water per day may help you achieve sustainable, healthy weight loss -- instead of eliminating water from your body by sweating.
Even if you've been drinking water to rehydrate your body while you exercise, you could still become dehydrated. Ideally, you should drink 2 cups of water for every pound of weight you have lost after exercising, notes the University of Arizona Campus Health Service. If you are unable to eat a small snack after working out, drink a sports drink that contains carbohydrates to raise your blood sugar and replenish the electrolytes you lost due to sweating. If you have a headache, feel lightheaded or feel extremely thirsty, see a doctor as soon as possible.