Can You Handle the Heat? Exercise Tips for Warm TemperaturesMarch 15, 2016
As winter winds to a close and temperatures begin to rise, we all will be heading outside to exercise and enjoy the sun with our family and friends. However, as our thermometers rise, we must be aware of how the heat is impacting our bodies. When we exercise in warm environments, heat cannot always be released at the rate it is being produced, which raises our internal body temperature. This excessive heat storage can lead to heat stress, dehydration, excessive strain on the heart and decreased athletic performance. Listed below are some important things to consider and practical ways to keep yourself performing at your peak as you venture outside to exercise this spring and summer.
Your body heavily relies on its ability to sweat in order to cool your internal system and manage your core temperature during physical activity. However, when you sweat, your blood loses volume, which excessively increases your heart rate and decreases your maximum exercise intensity. It’s important that you replace this sweat loss with fluids throughout activity to offset these changes in your system and avoid dehydration. Along with increased heart rate, dehydration can also cause decreased pacing ability, and reduced muscular strength, power, and high intensity endurance.
Individual sweat rates vary based on multiple factors such as age, exercise tolerance, sex, and fitness status so fluid replacement should be based on individual needs.
- Drink about 20-24 oz of water about 2-3 hours before exercise, than another 7-10 oz. about 10 to 20 min before exercise
- Drink 7 to 10 oz of water every 10 to 20 min
- Drink beyond your thirst. If you are feeling thirsty, you are already dehydrated.
- Weigh yourself before and after activity to get accurate estimate of fluid loss
- Weight loss >1% can negatively affect athletic performance
- Weight loss >3% after activity greatly increases the risk of heat illnesses such as heat cramps, heat exhaustion, or even heat stroke
- Individuals should drink approximately 20-24 oz of fluid per pound of weight loss within two hours of exercise
- Assess urine color to determine hydration status
- Properly hydrated individuals have urine that is clearer in color – it should look more like lemonade than apple juice
- Clear urine may indicate over-hydration
- Water is recommended for shorter (<75 minutes) bouts of exercise
- Sports drinks containing electrolytes, such as sodium or potassium, may be necessary after prolonged (>75 minutes) bouts of exercise. Limit their use in short duration activities because they often have high sugar content.
2. Body Cooling
Pre-cooling before physical activity creates a lower internal body temperature and enhances central blood volume return at the beginning of exercise. This allows for longer duration of activity before reaching a performance limiting body temperature. This technique is an inexpensive and efficient way to manage your body temperature before, during and after activity, and between multiple bouts of exercise. Colder items (towels, water, frozen water bottles, etc) encourage faster cooling, so the colder the better!
- Use ice water towels, frozen water bottles, and ice slurry drinks (mixture of small ice particles and water) to cool your system down
- Applying the cold towel or frozen water bottle to your armpits, neck and groin will cool you down faster due to the important arteries that run through these areas
- Ice water immersion (ice water baths) provides the fastest cooling rate
- Misting fans are optimal to enhance evaporative cooling in hot, dry conditions
3. Heat Acclimazation
Acclimatization refers to your body’s adaptations to the heat through reduced strain and improved heat release. This process takes approximately 10–14 days to fully occur. However, differences in personal fitness and geographic location can alter this timeframe. The physiological improvements from acclimatization include decreased heart rate, increased blood flow to the skin, improved vascular response, heightened sweat sensitivity and better water balance. Once these changes take place, you are better able to delay muscular fatigue in the heat due to an increased output by your heart. If you do not maintain consistent activity in the heat, the benefits of acclimatization begin to diminish after approximately 6 days of inactivity.
- Schedule outdoor exercise at the coolest time of day, either early morning or after sunset
- For individuals who work out in a heated room, begin exercise at approximately 50% workload for 1 hour and increase time and intensity slowly for 14 days
- If exercising outside, begin with short 15-20 minute bouts of activity and increase your exercise time slowly (increase outside exposure time 5-10 minutes per day)
- Utilize shaded areas when they are available, and don’t forget your sunscreen!
- Athletes who can integrate sport-specific drills (shuttle runs, agility drills and short sprints) in the heat twice a week for 30-45 minute will see improved performance and heat tolerance
Heavy or thick clothing can trap heat and decrease airflow to the skin, which decreases heat release and increases internal temperatures. Thin, loose-fitting, cotton clothing increases sweat evaporation rate and airflow to the skin. Once this takes place, you’ll notice decreased skin temperature and improved thermal comfort. Light colored clothing decreases heat absorption during activity much better than darker colored clothing.
- Wear loose fitting, cotton, and light colored clothing to increase air flow and reduce heat storage in the body
- Tight-fitting wicking material such as thin compression shirts/shorts can improve heat release
- Wear as little clothing as required during exercise
Utilizing these simple tips will not only ensure safety while you are exercising outside, but will keep you performing at your peak levels! Now go out there and enjoy the sun!