The importance of proper hydration for optimal functioning of the body can never be overstated. However, fluid and electrolyte replacement is a complicated subject! There are many factors that must be taken into account to achieve optimal hydration and electrolyte status. It’s not always as easy as simply downing a sports drink when you’re spending time in the heat, or post-training or competition; sometimes simply water or a mixture of water and electrolytes (like sodium, magnesium and potassium) is a better option.
The most important thing for someone exposed to high heat is to know that dehydration and electrolyte depletion will negatively impact how you feel, perform, recover, and your overall health.
Even a slight dehydration of 1-2 percent of body weight can compromise your health status and performance.
When you spend time in the heat with any excessive fluid loss, your health status can be compromised….for example, when an athlete sweats excessively during intense training or competition, a loss of electrolytes also becomes a compromising factor. Any further fluid loss increases the risk of heat cramps, heat exhaustion and heat stroke.
Prior to exercise or exposure to hot temperatures, most people should focus on hydrating with water to adequately prepare for the sweat loss ahead.
A good rule of thumb is to drink 16-20 ounces of fluid two to three hours prior to activity, and then another 8- 10 ounces of fluid 10-20 minutes before exposure. During training or competition, athletes are encouraged to ingest 8-10 ounces of fluid every 15-20 minutes of intense exercise or at whatever rate maintains less than 2% body weight reduction by sweat loss.
These recommendations are applicable to an athlete participating in any sport or for a person completing routine exercise.
After completion of intense or prolonged activity, the goal is to re-hydrate and recover any fluid loss within two hours. I suggest ingesting a drink containing water, carbohydrates and electrolytes (See a graph of popular drinks below).
“The sodium in sports drinks can be helpful in warding off a condition called ‘hyponatremia’ in extreme athletes who sustain physical activity for more than four hours at a time,” said W. Larry Kenny, professor of Physiology and Kinesiology at Penn State. He suggests that any person participating in intense activity for longer than 45 minutes choose a sports drink over plain water. This also applies to anyone who naturally has a higher than normal sweat rate.
However, athletes who engage in less intense, shorter duration or stop-and-start activities should be mindful that their sports are less apt to create the physical need for large amounts of sports drinks.
Robert Rogbergs, an exercise physiologist at the University of New Mexico, states that unless someone is exercising or competing in a sporting event for longer than 90 minutes, there is no reason to drink something like Gatorade with excess sugar and electrolytes. These supplements can actually lead to GI distress, further impairment of fluid balance or salt-induced cramps. In addition, excess electrolytes like potassium can lead to adverse health effects. A solution for those who must have their sports drinks is to simply dilute them with water to half strength, and add glycerol, which helps the body absorb and retain water. This will help increase sweating during exercise to maintain a constant body temperature.
Proper hydration is a necessary part of pre and post exercise and those exposed to high heat, both in training and daily activities. However, because of the many variables involved, you must be mindful of and address your specific needs, particularly when it comes to post-event hydration and re-fueling. Finding the right individual formula is imperative in proper recovery and thus preparation for further events!
