[This post is written by Cliff Scarborough who is currently working as a Sport Performance Intern at Athletic Lab]

When it comes to sports performance, maintaining a healthy level of hydration is one of the key elements in the ability to produce great results. The National Athletic Trainers Association (NATA), states that improper hydration can lead to negative performance during practice as well as competition due to lack of muscle lubrication which effects muscle elasticity, strength and endurance. Evaporation is usually the primary mechanism of heat dissipation in an effort to assist the body in regulating core temperature, which rises if the body cannot adequately evaporate sweat. During this process, there is a loss of valuable fluids. Dehydration occurs when an athlete’s sweat loss exceeds fluid intake. The rate of sweat loss is determined by the intensity of exercise, environmental conditions, acclimatization state, clothing (type and color), and baseline hydration status along with individual sweat rate. The term dehydration, is defined by a 2% loss of body weight. This begins to compromise physiology and can start to have negative influences on performance. When an athlete experiences heat cramps, heat exhaustion, or heat stroke he or she is usually higher than 3% past dehydration.

Most athletes do not drink the proper amount of water; however, it is possible to improve drinking behaviors through education, increasing accessibility and optimizing palatability. It is also important to avoid over-hydrating because it can potentially compromise physical health and performance as well. It is recommended that athletes consume 17 to 20 ounces of water or sports drink 2 to 3 hours prior to exercise, another 7-10 ounces 10 to 20 minutes before starting exercise to ensure proper hydration and 7-10 ounces of fluids every 10 -20 minutes once exercise has started. For rehydration, The American College of Sports Medicine (ACSM) recommends that you gradually drink about 23 fluid ounces of fluid for every pound of weight lost during exercise.

Other general recommendations to hydrate properly are as follows:

  • Ease of access to beverages.
  • Individual containers to insure easy monitoring of intake.
  • Athletes should be checked for hydration through urine color or pre-exercise body weight before practice.
  • Rehydration should take place within two hours after exercise or practice is done. Cool water for rehydration, carbohydrates for glycogen replenishment and electrolytes to speed up rehydration.

Another factor that should be taken into consideration when monitoring an athlete’s hydration state is weather change and timing of competition or practice to ensure proper fluid intake.

To decrease the likelihood of dehydration and the negative side effects, events should be scheduled in the cooler part of the day. Light colors should be worn over darker colors and athletes should be encouraged to educate themselves on hydration protocol to ensure their own safety while exercising or competing.

Sports drinks like Gatorade that have less the eight percent carbohydrates (CHO) and sodium are recommended for consumption. These drinks are absorbed easily and are well tolerated by the body. Beverages containing more than eight percent carbohydrates (CHO), caffeine, carbonation, and alcohol should be avoided because of the high risk of dehydration associated with urine production, or decreased voluntary fluid intake.

References:

1 Sawka MN, et al. (2007). Exercise and fluid replacement. American College of Sports Medicine; . American College of Sports Medicine position stand. . Med Sci Sports Exerc ;39:377-390.

2 Jason Brumitt. (2004). NSCA’s Performance Training Journal.

3 National Federation of State High School Associations (NFHS) Sports Medicine Advisory Committee (SMAC), POSITION STATEMENT AND RECOMMENDATIONS FOR HYDRATION TO MINIMIZE THE RISK FOR DEHYDRATION AND HEAT ILLNESS. April 2008