Note to Reporters: The following column was written by Melissa Wdowik, an assistant professor at Colorado State University in the Department of Food Science and Human Nutrition, and director of the Kendall Anderson Nutrition Center.
With students heading back to school, fall sports are in full swing. In addition to training, eating right, and getting enough sleep, a significant key to health and performance is staying hydrated. However, the recent tragic death of a teenage athlete is an important reminder that you can get too much of a good thing.
Hydration means having adequate fluids in the body to be able to sweat, circulate blood, lubricate joints, and transport oxygen and nutrients throughout the body.
Overhydration, or water intoxication, means the body has taken in too much water. Also called hyponatremia (low sodium in the bloodstream), overhydration occurs when someone drinks too much water in a short period of time, so that other nutrients, especially sodium, become too diluted to function properly. It may lead to muscle spasms, stomach and leg cramps, nausea, vomiting, weakness, confusion, and even death.
Dehydration is more common than overhydration. Dehydration means the body is losing more fluids than it is taking in, and often leads to muscle fatigue, loss of coordination, excessive body temperature, cramps, and decreased performance. Athletes are more likely to become dehydrated if they drink coffee, soda or energy drinks throughout the day.
The trick for both teens and adults is to take in the right amount of fluids to avoid dehydration but without going overboard. Limit fluid intake to 1 quart per hour (or 1 liter per hour) and follow these tips for optimal hydration for both teen and adult athletes.
Drink throughout the day. Start exercise already adequately hydrated by drinking, on average, 8 cups of water every day. Thirst is not a good indicator of how hydrated you are; instead, drink before you are thirsty. It helps to have a goal of drinking one water bottle (for example, 24 ounces) by lunchtime and another by the final school bell. A good way to make sure the body is hydrated is by paying attention to urine, which should be a pale yellow color.
Before exercise, drink 8-12 ounces 15 minutes before your activity. This may be water or a sports drink. If this is a new habit and causes an upset stomach, start with just 2 ounces 15 minutes before exercise and gradually add 1 ounce to this intake every 2-3 days until you reach 8 ounces.
During exercise, sports and exercise experts recommend 3-8 ounces every 15-20 minutes. If you are exercising less than 60 minutes, this should just be water. If you are exercising more than 60 minutes, this should be a sports drink. In truth, many athletes either do not want to drink every 15-20 minutes, do not want to carry fluids with them, or are not given the opportunity. If this is the case, it is even more important to start your exercise session already hydrated.
After exercise, athletes need to drink 20-24 ounces of water or sports drink for every pound lost. If you do not want to weigh, a good rule of thumb is to drink that 20-24 ounces, then continue to hydrate for the next 24 hours by maintaining pale urine.
Everyone has different sweat rates and sweat electrolyte contents, so experiment to figure out what works best for you. With common sense and a hydration plan, athletes can achieve their optimal performance and stay healthy at the same time.
Melissa Wdowik, PhD, RDN is an assistant professor at Colorado State University in the Department of Food Science and Human Nutrition, and director of the Kendall Anderson Nutrition Center.