Monitor athlete’s hydration before, during, and after exercise. An appropriate hydration strategy involves athletes beginning exercise hydrated, minimizing fluid losses during exercise, and replacing fluid losses after exercise. Calculate an athlete’s sweat rate in order to replace fluid losses that occur during exercise:
1. Calculate sweat rate in a hydrated state. Light colored urine.
2. Take a nude body weight before the workout
3. Exercise for one hour (at an intensity similar to the conditions
in which knowledge of sweat rate is needed).
4. During the one-hour workout refrain from drinking fluids. If water is consumed, weigh the water before and after to include this in the calculation.
5. Once the workout is complete, take another nude body weight. Calculate the difference between pre and post exercise body weight. If water is consumed, subtract it from the post exercise body weight.
6. Every 2.2 pounds a person loses equates to 1 liter of fluid loss (sweat loss). For example, if someone loses 5 pounds in 1 hour their sweat rate is 5/2.2 = 2.27 liters/hour.
7. A person’s sweat rate is the amount of fluid they should aim to replace during exercise.Fluid losses greater than 2% can negatively impact performance and increase the risk of EHI.
Exercise in the heat while in a hypohydrated state (a steady- state condition of decreased total body water) can put an athlete at risk for EHI. The body relies on evaporative heat loss to dissipate the heat produced during exercise. Skin blow flow increases to dissipate heat, this leads to a competition between the skin, working muscles, and cardiovascular system for blood. This can decrease cardiac output and ultimately decrease performance, because of an increase in heart rate and a decrease in plasma volume. Influence of hydration and intense exercise in the heat.
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