Back-to-School News Distributed 07/11/08
High heat and humidity during preseason football practice pose a significant danger for heat illnesses and heat stroke. Athletes need adequate fluids for their best performance, according to LSU AgCenter nutritionist Dr. Beth Reames.
The risks of dehydration and heat injury increase dramatically in hot, humid weather.
Dehydration causes cramps, weakness and headaches.
“Dehydration can lead to higher body core temperature, which increases strain on the cardiovascular system and may lead to heat stroke, heat injury and even death,” Reames said.
Adequate fluid replacement helps maintain hydration and, therefore, promotes the health and safety of athletes, according to the American College of Sports Medicine. Experts recommend athletes hydrate with fluids before, during and after activity or competition to help regulate body temperature and replace body fluids lost through sweat.
Dehydration of just 1 to 2 percent of body weight (only 1 1/2 to 3 pounds for a 150-pound athlete) can negatively influence performance. Dehydration of greater than 3 percent of body weight increases an athlete’s risk of heat illness, which includes heat cramps, heat exhaustion and heat stroke.
According to the 2005 Consensus Statement on Youth Football: Heat Stress and Injury Risk in the Journal of the American College of Sports Medicine, fluid replacement should be encouraged by providing chilled fluids that are easily accessible with adequate time to drink them. This strategy will promote sufficient fluid intake to lessen progressive dehydration on the field.
Reames offers these tips for proper hydration:
– Drink before, during and after practices and games.
– Drink early; by the time you’re thirsty, you’re already dehydrated.
– Include liquids with the pre-competition meal.
– Drink fluids based on the amount of sweat and urine loss during the activity.
– Drink cool fluids.
– Replace fluids lost in sweat and urine after the competition.
The nutritionist recommends water for most types of exercise of one hour or less under moderate temperature conditions. For intense exercise lasting longer than one hour, she recommends sports drinks or diluted juices containing carbohydrates in concentrations of 4 to 8 percent. Carbohydrates provide energy. She adds that these beverages are also suitable for exercise events lasting less than 1 hour.
Since sports drinks are flavored beverages, athletes often prefer them over plain water.
Reames explains that sports drinks replace electrolytes such as sodium (which is lost in sweat). Foods eaten after the event, however, are usually sufficient to replace sodium.
The American Dietetic Association recommends that athletes should drink about 2 cups of fluid about two hours before exercise or competition. During exercise, they should start drinking early and drink regularly, such as one-half to 1 cup of fluid every 15 to 20 minutes. After exercising, they should drink at least 2 cups of fluid per pound of body weight lost during exercise.
“If athletes compete under hot, humid weather, take every precaution to assure they are well-hydrated, have ample access to fluids and are monitored for heat-related illness,” Reames said.
For related information, click on the Food and Health link on the LSU AgCenter home page at www.lsuagcenter.com. For local information and educational programs, contact an extension agent in your parish LSU AgCenter office.