Note: I had planned on writing an awesome post on creatine for today. But on Tuesday I made the soul crushing discovery that I have misplaced the USB that has all of my research and documents from 2007 to the present, including all of the reports I’ve done on creatine. So, for now, enjoy this post about hydration, and stay tuned for said awesome post on creatine next week, when I either find my USB or have enough time to re-do all my research.
It’s been hot this summer. While we’re flirting with fall weather this week, the weatherman tells me the heat and humidity will be back by the weekend. Dehydration - when your body does not have enough fluid to function normally – happens when you lose more fluid, usually from sweating, than you are able to take in. You are considered to be in a state of dehydration when you lose 2-3% of your body weight in fluid. At a loss over 3% of your body weight – which for a 150 lb person is 4.5 lbs – you can begin to see impairment in motor function and mental ability – meaning you will start to feel confused, uncoordinated, and fatigued.
How much water do you need? On average you need about 30 milliliters (ml) of fluid per kilogram (kg) of body weight to maintain hydration. For most people this is around 2 liters, or the commonly suggested “8 glasses a day”. However there are many factors that can increase the amount of fluid you need. These include:
- Weight - People who weigh more need more water. So while a 120-pound athlete needs just under 7 glasses of water per day, his or her 180 pound coach would need a little over 10 glasses to stay well hydrated.
- Climate - Dehydration can occur in all types of weather. When it is hot you lose more water to sweat, and in colder weather you may not sweat as much but you will lose more fluid during breathing. Yes, you can lose fluid this way! The average person loses about 500 ml, or 2 cups, of water per day simply breathing. And according to one study, you can lose 42% more water, or almost a cup, when you breathe through your mouth instead of your nose.
- Altitude also increases fluid needs, and experts recommend those exercising at higher altitudes drink 3-4 liters of water per day.
Hydration for Athletes
The number you just found is the amount of water you need before accounting for exercise. During exercise, you will need to drink some extra water. For optimal hydration, and give your body time to get rid of any excess fluid, drink 2-3 ml per pound of body weight 4 hours before exercise. Try to drink 8 ounces of water 15 minutes beforehand, and then continue to drink during the workout. A good rule is to drink enough water so that you feel energized and avoid thirst, but don’t drink so much that you feel full. This usually adds up to around 8-16 ounces per 30-60 minutes of exercise. After training you will have lost some fluid and need to replace it. Generally, the recommendation is to weigh yourself before and after practice, and drink 24 ounces of water for every pound you lost. After a few practices you will get an idea of how much you normally lose, and won’t have to do this very often.
Electrolytes also play an important role in hydration. The most common electrolytes are:
Sodium regulates the total amount of water in the body and maintains the proper function of nervous, muscular, and other systems.
Chloride helps maintain a normal balance of body fluid.
Potassium is responsible for regulating heartbeat and muscle function and is important in neuron function. Extreme high or low potassium levels can cause irregular heartbeat, which can be fatal.
Bicarbonate maintains the right amount of acidity in the blood and bodily fluids. *This is important because muscle cramping is most often related to an accumulation of acid in the muscles.
When you sweat, you lose electrolytes in addition to fluid. Gatorade, and most other recovery drinks, have 100-120 mg of sodium, and the following foods have at least that much, if not more, in a common serving size: salted nuts and seeds, trail mix, deli meat, eggs, most dairy products, canned tuna, humus, olives, pickles, and raw or cooked spinach. Most sports drinks contain about 30-90 mg of potassium, but this electrolyte can be replaced by eating foods such as raw nuts, yogurt, milk (or chocolate milk), fish, sweet potatoes, tomatoes, beans, peaches, and melons. Most of the time, unless you are training for an extended period (greater than 90 minutes) or in very hot or humid weather, sports drinks are generally not needed to maintain hydration and electrolyte balance.
But…don’t overdo it! While it is important to maintain fluid balance and avoid dehydration, it is possible to become over hydrated. This happens when you drink significantly more water than is lost with sweat, causing sodium levels to drop. Your body likes things to be in a nice, balanced place, and when things get too high or too low your body will tell you. Low sodium levels usually mimic heat stroke symptoms, and let you know something is up with dizziness, headaches, nausea, irritability, and confusion. Over hydration happens primarily with endurance athletes (marathon runners or cyclists, for example) and as a power athlete your risk for this is not as high. But it is important to keep in mind, especially if you’ve been hydrating well in hot weather and still feel like you might have heat illness. If this happens to you, stop training, and have a sports drink or eat something salty.