August 1, 2019

Staying safe in the heat for high school athletes

Many high school athletes have already returned to sports camps in preparation for the fall season. The challenge is that during July, August and even September, we can experience some of the hottest days of the year.

With the high temps, athletes need to be aware of how environmental factors like heat and humidity can affect their health and athletic performance.

How heat affects the body

As heat and humidity rise our body has to work harder to cool off. Our bodies cool primarily through the evaporation of sweat. When temperatures rise, we produce more sweat to cool the body. As the humidity rises, it becomes more difficult for the sweat to evaporate hampering the ability of the body to cool off. It is one reason why it is important for athletes to drink fluids during the day and at practice to stay adequately hydrated, and to modify practice routines based on weather conditions.

Recommendations for exercise in the summer

Even before the temperatures start to soar, there are ways you can help get your body ready for practicing in the heat and staying safe when you do.

Acclimatization (getting used to the temps)

Acclimating the body to exercising in the heat is important for staying safe. Hopefully by now youth athletes have been actively playing outside even before camps began. If jobs or activities have prevented it, try to start at least two weeks before camp. Begin by doing a small amount of exercise outdoors in the heat and humidity and gradually increase the amount and intensity of the exercise over the two weeks until reaching the level of activity that will be taking place during camp. Remember, even when we are used to working out in the heat, we still require an increased level of water to stay hydrated but our bodies will be better able to tolerate the heat.

Pay attention to the heat

While the thermometer may read 80 degrees, the combination of heat and humidity can mean it feels much warmer out. While many are familiar with the heat index, which measures the combination of temperature and humidity, what many may not realize is that it is based on temperatures in the shade — meaning the temperature is even hotter in the direct sun. Because many activities take place in direct sunlight — certain outside jobs, military activities and of course sports activities - another type of temperature measurement known as the WetBulb Globe Temperature (WBGT) may be used. WBGT takes into account more than just the humidity, and includes wind speed, cloud cover and sun angle. The American College of Sports Medicine and the National Athletic Trainers Association (NATA) recommend WBGT for determining when to modify activity on hot days.

Modify activity

As the temperature increases, outdoor activities should be modified to prevent heat-related illnesses. NATA recommends the following:

  • Under 82°F: Normal activities with 3 separate rest breaks — a minimum of 3 minutes each — for every hour of workout.

  • 82°F-86.9°F: Use discretion and watch players closely. Maintain 3 separate rest breaks, but they should be a minimum of 4 minutes each.

  • 87°F-89.9°F: Practice time should not exceed 2 hours. All protective equipment must be removed for conditioning activities and there should be 4 rest breaks per hour each at least 4 minutes long.

  • 90°F-92°F: Practice time should not exceed 1 hour. No protective equipment should be worn during practice and no conditioning activities. A minimum of 20 minutes of rest breaks should be provided during the hour of practice.

  • 92°F or above: No outdoor workouts and exercise should be cancelled. Outdoor practices should be delayed until WBGT temperatures are cooler.

Stay hydrated

Staying hydrated is critical, especially when the temps start to soar. Athletes should begin practices or games already well hydrated, and during exercise aim to consume the same amount of water that is lost through sweat. While everyone's body is different and the demands vary by sport or activity, a general guideline to follow is:

  • 17-20 ounces of fluid within 2 hours before exercise

  • 7-10 ounces every 10-20 minutes during exercise

  • 16-24 ounces per pound of body weight lost during exercise

Urine can be one sign of dehydration, although certain foods or food additives can affect the color. Generally speaking, clear to pale yellow generally means well hydrated, while yellow to light honey color means the body needs more water. Urine that is more orange in color can be a sign of serious dehydration or health problem and may require medical care.

For training sessions or games lasting over an hour, a carbohydrate and/or electrolyte beverage (sports drink) is generally recommended to help restore the body. As the season progresses, the heat and humidity will become less of an issue. But, with proper planning athletes can stay healthy and safe when on the practice field and during those early fall games.