You're exercising and you know you need to stay hydrated. You see people around you drinking water and you see others around you drinking sports drinks. But which should you choose? And just how much of either should you be drinking?
Water is an essential part of keeping your body temperature normal. Exercise can speed up normal water loss from sweat. If you don't drink enough, you can become dehydrated. This can affect your performance and make you tired, cause dry mouth, headaches, light-headedness and even constipation.
If you are not properly hydrated, you may be at increased risk of developing heat-related illnesses, such as heat exhaustion or heat stroke.
How much fluid you should drink depends on several variables, including:
- Type and intensity of your exercise
- How long your exercise will last
- Your age, body size, weight and muscle mass
- How much you sweat
- Heat and humidity conditions
You should be well-hydrated when you start exercising. As a rule of thumb, drink 3 to 8 ounces of fluid for every 15 to 20 minutes of exercise, possibly more on hot days. Drink plenty after exercise, as well.
Don't wait until you're thirsty to start drinking. Thirst is a sign that your body has already been without fluids for a while.
About sports drinks
If you work out for fewer than 60 minutes, water is usually all you need. If you work out longer than 60 minutes, sports drinks do have a place. If you work out in very hot or humid weather, you may need a sports drink if you work out for less than 60 minutes, too.
When you sweat, you lose water and salts. If you don't replace them, you can become dehydrated. Sports drinks contain electrolytes like sodium, potassium, magnesium, calcium and water. This combination replaces the fluids in your body faster than water can. Sports drinks also contain carbohydrates, which give you the calories you need for fuel.
Read the label on your sports drink. Make sure it contains between 4 and 8 percent carbohydrates. More than 8 percent can cause cramping, diarrhea and nausea.
Can you drink too much water?
Though rare, it is possible to drink too much water. Hyponatremia can be life-threatening and usually happens either when someone drinks too much water or when a person sweats heavily for a long period of time and doesn't replace the lost sodium. This condition is mainly seen in endurance athletes, like marathon runners.
Talk to your doctor if you have any concerns about exercise and hydration.
Created on 01/04/2007
Updated on 02/23/2013
- American College of Sports Medicine. ACSM information on ... selecting and effectively using hydration for fitness.
- American Academy of Nutrition and Dietetics. Hydrate right.
- UpToDate. Exercise-associated hyponatremia.
- American College of Sports Medicine. ACSM information on ... selecting and effectively using sports drinks, carbohydrate gels and energy bars.