August 2001 "High Temperatures and Exercise"

Injury rates increase during summer workouts whether athletes are in peak physical condition or not. In fact, many athletes don't even make their starting lineup because of injuries incurred during pre-season workouts. Here are some tips to help ensure athletes stay at their best and prevent heat related injuries:

  • Begin conditioning before two-a-day workouts.
  • Begin conditioning in the heat two weeks before official practice begins. This allows the body to cool more efficiently by increasing sweat production sooner than when they are not acclimated to the heat.
  • Avoid workouts during unusually hot conditions. Practice sessions during unusually hot and humid conditions should be limited to very moderate workouts, postponed until cooler times of the day or moved inside to avoid the heat.
  • Make fluids part of the play book. Before, during and after competition, be sure to consume adequate amounts of fluid. Athletes can make sure they are properly hydrated by checking their urine color: lighter urine color indicates athletes are better hydrated. The longer the workout session, the more frequently fluids need to be replaced. Research shows that a sports drink containing a 6% carbohydrate solution, like Gatorade, can be absorbed as rapidly as water. But unlike water, a sports drink can provide energy, delay fatigue and improve performance.

Signs of Dehydration and Heat Illness

Dehydration can seriously compromise athletic performance and increase the risk of heat injury. That's why it's important to recognize the warning signs: thirst, irritability, headache, weakness, dizziness, cramps, nausea and decreased performance. Follow these general guidelines:

  • Use the Shade. Before practice, warm up in the shade and be sure to rest in the shade during breaks. Even during rest, exposure to heat can raise the body temperature, increase fluid loss and decrease blood available to the muscles during workouts.
  • Wear Loose Fitting Clothing. Cotton blend, loose fitting clothing can help promote heat loss. The rule is the less clothing, the better.
  • Be Prepared for an Emergency. Always have a cell phone on hand and be familiar with emergency numbers. Also keep ice and ice towels on hand in case of heat-related emergencies.

Fluid Guidelines for Exercise

Proper hydration is the best safeguard against heat illness. Remember to have athletes drink before, during and after training and competition. General guidelines for fluid use are as follows:

  • Before Exercise: 2 to 3 hours before exercise drink at least 17 to 20 oz of water or a sports drink. 10 to 20 minutes before exercise drink another 7 to 10 oz of water or a sports drink.
  • During Exercise: Drink early-Even minimal dehydration compromises performance. In general, every 10 to 20 minutes drink at least 7 to 10 oz of water or a sports drink. To maintain hydration, remember to drink beyond thirst. Optimally, drink fluids based on amount of sweat and urine loss. Athletes benefit in many situations from drinking a sports drink containing carbohydrates. If exercise lasts more than 45 to 50 minutes or is intense, a sports drink should be provided during the session. The carbohydrate concentration in the ideal fluid replacement solution should be in the range of 6% to 8% (14 to 18 grams per 8 oz). Fluids with salt (sodium chloride) are beneficial to increasing thirst and voluntary fluid intake as well as offsetting the amount in lost sweat. Cool beverages at temperatures of 50 to 59 F are recommended. Don't drink fruit juices, carbohydrate gels, sodas and those sports drinks that have carbohydrate levels greater than 8%. Beverages containing caffeine, alcohol and carbonation are discouraged during exercise because they can dehydrate the body by stimulating excess urine production, or decreasing voluntary fluid intake.
  • After Exercise: Immediately after training or competition is the key time to replace fluids. Weigh athletes before and after exercise. Research indicates that for every pound of weight lost athletes should drink at least 20 oz of fluid to optimize re-hydration. Sports beverages are an excellent choice.

Managing Two-A-Days

  • Stay Cool
  • Get in shape and acclimate
  • Know the warning signs of dehydration and heat illness
  • Don't rely on thirst to drink
  • Drink throughout the day
  • Monitor body weight
  • Watch urine color and caffeine intake
  • Key on meals as an opportunity to increase fluid intake
  • Stay cool when you can
  • Stay healthy
  • Minimize the stresses of life
  • Eat a well-balanced diet
  • Avoid overtraining
  • Sleep well
  • Avoid rapid weight loss
  • Avoid people with colds
  • Keep hands away from nose and mouth
  • Stay hydrated and ingest carbohydrates during exercise
  • Drink at least 17 to 20 oz of fluid 2 to 3 hours before a practice or game
  • Drink an additional 7 to 10 oz of fluid 10 to 20 minutes before competition
  • Drink 28 to 40 oz of fluid per hour of play (at least 7 to 10 oz every 10 to 15 minutes) to replace sweat loss during exercise
  • Drink at least 20 oz per pound of weight loss within two hours of finishing training or competition