Courtesy of Megan Moran & the physical therapy/sports medicine team at MedStar NRH Rehabilitation Network, Marymount – Arlington, VA

Warmer weather is upon us and therefore it is a good time to review the importance of hydration during exercise.

Sweating is an important process that helps with temperature regulation of the body. The evaporation of sweat helps to cool the body’s temperature, but sweating leads to the loss of valuable fluids. Dehydration is the loss of too much of the body’s fluids and leads to negative effects on body functions. Dehydration with loss of 1-2 percent of the body’s weight may have a negative impact on sports performance and lead to an increase in heart rate, changes in mental function, decrease in muscle strength and endurance and a decrease in aerobic capacity. 

Even greater dehydration, greater than 3 percent loss of body weight, can lead to more severe conditions such as heat creams, heat exhaustion, or heat stroke.  Signs of dehydration include thirst, irritability, headache, weakness, dizziness, cramps, chills, vomiting, nausea, and decreased performance. Those who have a history of heat-related conditions such as heat cramps are at greater risk to experience another heat-related illness. 

What can be done to prevent the negative effects of fluid loss during exercise? 

• It is important to hydrate properly everyday, throughout the entire day. 
• Two to three hours prior to exercise, consume 17-20 ounces of water and another 7-10 ounces 20 minutes before exercise. 
• After exercise, rehydration should be completed within two hours.
• Water is great to rehydrate for short bouts of exercise, but for longer episodes (greater than 45 minutes) fluids with electrolytes and carbohydrates are beneficial. 

Carbohydrates replace lost glycogen and the electrolytes increase the speed of hydration. Although weight change is the best way to assess fluid loss during exercise, urine color can be used for a quick and inexpensive estimate. Be sure to speak with a sports medicine specialist if you have specific questions or concerns. 

For more on our MedStar NRH Rehabilitation Network, Marymount site click here – http://www.medstarnrh.org/our-network/locations/marymount/

Their address/contact info is below:

Marymount
4040 N. Fairfax Dr., Suite 120
Arlington, VA 22203
703.292.4060
[email protected]

*Source: Casa DJ, Armstrong LE, Hillman SK, et al. National Athletic Trainers’ Association Position Statement: Fluid Replacement for Athletes. J Athl Train. 2000;35(2):212-224.