When the weather warms up, it is important to take a few precautions when running outside in the heat. Here are some tips to help you keep safe during your hot weather runs.
Drink water and electrolyte drinks. Dehydration occurs when the body loses fluid. As you sweat when running, your body loses both water and electrolytes. This mean that it is important to drink a sports drink containing electrolytes as well as water, especially if you plan to be out longer than an hours. You should aim to drink between 4 and 8 oz. of water and/or sports drink every 15 to 20 minutes.
Take time to acclimate. It takes roughly two weeks of consistent running in the eat and humidity to acclimate to the warmer conditions. If you travel to someplace that is hotter or more humid than the place where you live, don't plan on running at the same speed, intensity, or length without acclimating first.
Wear sunscreen. Apply sunscreen of at least SPF 15. Also, make sure you use a non-drip formula so it does not drip into your eyes as you sweat.
Wear sunglasses and a hat/visor. Your sunglasses should filter both UVA and UVB rays. Also, choose a hat or a visor that breathes and wicks away sweat.
Wear light-colored clothing. Dark colors attract and absorb the heat, so you want to choose light colored clothing that will reflect the sun and wick away the heat. Choose white or pastel tops and shorts. Always wear micro-fiber, moisture-wicking materials rather than 100 percent cotton. Remember the saying, "cotton is rotten".
Avoid running during peak sun and ozone hours. Try to run early in the morning or in the evening after the peak sun hours to avoid the heat. During the summer, the hottest part of the day is between 2 and 5 pm. Besides the cooler temps, the morning and evening are also best in terms of air quality. Ozone levels increase soon after dawn, peak at midday and then begin to decrease in the evening.
Check the Heat Index Chart. The Heat Index Chart calculates what the temperature feels like based on the air temperature and relative humidity. This can be important for determining if there is a risk of a heat-related illness, such as heat exhaustion or heat stroke. Check the Heat Index Chart before you head out for your run. If it is too high, consider heading indoors or skipping your hot weather run.
Drink an icy, sweet drink before running. Try drinking an ICEE, slushie, or smoothie before heading out for your run to bring your core temperature down. If that's not possible, opt for an ice-cold glass of water. Researcher from New Zealand found that runners who had an icy, sweet drink before their workout ran 10 minutes longer on a treadmill in a heated room than runners who drank syrup flavored cold water. The icy drink lowered their core temperatures, so they were "pre-cooled", allowing them to run longer before their bodies overheated.
Don't be afraid to bag it. If it is a particularly hot day or you didn't wake up early enough to beat the heat, consider skipping your workout or heading indoors to use a treadmill, take a spin class, or swim. And if you start your run and feel miserable, don't be afraid to throw in the towel and stop. It's not worth the risk of heat illness.
Training Program Coordinator
RRCA Certified Coach
Fleet Feet Sports Certified Coach
Fleet Feet Sports, Gaithersburg, MD