Welcome to summer! It’s going to be a hot one out there today, but don’t let that scare you away from sticking to your fitness plan and getting in your run. Even as temps rise across the country, you don’t need to put your fitness plan on hold and spend your days huddled next to the air conditioner. You just need to learn how to run in the heat. By making just a few smart adjustments to your running routine, you can stay safe and keep your training on track.
Know the Risks of Running in Extreme Heat and Humidity
During the grilling days of summer, safety needs to be your primary concern. Even moderately warm days, combined with high humidity, can increase the risk of a heat-related illness. Just ask the runners of the Hamburg half-marathon in Germany. During the race in June of 2019, over 140 runners required medical treatment for heat-related illnesses and 57 runners were taken to the hospital after temperatures reached 95 degrees (Fahrenheit) during the race.
Running in the heat without the proper preparation can lead to:
- Heat cramps
- Lightheadedness or fainting (called heat syncope and exercise-associated collapse)
- Heat exhaustion
Heatstroke, in particular, can be life-threatening, so it is critical that you learn how to run in the heat, especially if you plan on running in extreme heat or humidity. Here are five simple and easy tips to run smart and safe during the hottest days of the year.
Tip 1: Run Early or Run Late
The best way to avoid heat-related illness while running is to… well, avoid the heat. If you love running outside, set your alarm clock a little earlier in the morning or embrace running in the dark.
Running in the morning will help you stay cool and may let you enjoy some beautiful sunrises. If you choose to run at night, be sure to invest in safety equipment. We recommend that you use a headlamp and/or hand lights to brighten your path and wear a reflective vest. You may even want to purchase a blinking tail light to clip onto your vest so that you’ll be extra visible to tired drivers.
Tip 2: Hydrate, hydrate, hydrate!
You should already bring water with you on all your runs regardless of the weather, but hydrating is extra important on hot and muggy days. As soon as your body begins to heat up, your brain will send a signal to your sweat glands to unleash the water works. As sweat evaporates, it will help to cool your body. You’ll also lose water naturally through your breath.
You need to replace this water so that your body can continue to function. If you don’t hydrate properly, your blood volume will drop and your heart will have to work harder to pump blood throughout your body. Your body may also struggle to cool itself, which can be dangerous during warm weather.
Not hydrating properly can also hurt your performance. When trainer Amanda Carlson performed a study of college football players, she found that losing just 2% of their body weight in fluid resulted in a performance decrease of up to 25%.
Research also indicates that many runners aren’t very good at estimating their hydration. In one study described in an article on WebMD, seasoned runners participating in a 10-mile race “underestimated their sweat losses by an average of 46% and their fluid intake by an average of 15%, resulting in the runners replacing only 30% of their fluids lost through sweat.”
To stay hydrated, start the day before your run by chowing down on foods that hydrate. During your run, bring more water than you think you need. It might not be enough to carry a single water bottle with you. Consider purchasing a water belt, water vest, or even a hydration pack from your local fitness store or online retailer.
Tip 3: Add Electrolytes
When you sweat during your warm weather run, you aren’t just losing precious water. You’re also losing electrolytes. These important minerals deliver fluids to your cells and also play a role in muscle and brain function. If you sweat heavily during your run and don’t replace that lost sodium, you could experience painful symptoms like muscle cramps and headaches. An even bigger threat is developing hyponatremia, which could lead to seizures.
In an article for U.S. News, Kelly Pritchett, an assistant professor in nutrition and exercise science at Central Washington University, explains that the average person loses about one gram of sodium per liter of sweat. Since it can be hard to estimate how much sweat, especially if you are running in extreme heat and humidity, it’s best to be overly cautious and take plenty of electrolytes during your runs.
Fortunately, that’s easier than ever. Many runners favor taking simple salt tablets. Others drop flavored electrolyte tablets into their water or eat electrolyte gels or gummies during their runs. Sports drinks can also give you some electrolytes (though not as many as you think). After your run, replenish your electrolytes by grabbing a high potassium snack, like a banana, a slice of avocado toast, or this delicious green smoothie.
Tip 4: Pace Yourself
Running in the heat puts your body under extra stress, which will affect your performance. When your body has to produce copious amounts of sweat to keep you cool, it can’t spend that extra energy on your muscles.
In a study published in Medicine & Science in Sports Exercise, exercise physiologist Matthew Ely discovered that even in the relatively comfortable temperature range of 50 to 59 degrees Fahrenheit, top marathoners experienced a four- to eight-minute drop in their time. Ely found that the optimal temperature for running (at least for male pro athletes) was a chilly 40 degrees.
Unsurprisingly, the hotter the day, the more an athlete’s performance tends to lag. In temperatures between 70 and 79 degrees, Ely and his team found sub-elite marathoners lose up to 20 minutes on their marathon time.
Research also indicates that larger athletes perform worse in warmer weather, likely because their bodies have to work harder to keep them cool. What this all means is that you need to pace yourself during runs in hot weather. Give your body a chance to adapt to the heat and consider slowing your pace.
Know your body and let it tell you how hard to push. Check in with yourself during the run and stop if you start feeling any symptoms of heat illness, including:
- Muscle cramps
- Nausea or vomiting
- Pounding heart
- Blurred vision
Your safety always comes first, so turn down those jets and don’t go for any personal records.
Tip 5: Stay Indoors
If it gets so hot you can fry an egg on the sidewalk, then it’s time to consider staying indoors and taking advantage of the modern marvel known as air conditioning. In some cases, it just isn’t worth it to put your body through the pain, discomfort, and risk of running in extreme heat and humidity. Instead, jump on a treadmill at home or in the gym. Don’t let the heat sabotage all your fitness progress.
If you struggle to run on a treadmill, then consider switching up your fitness routine. Who says you can’t enjoy some laps in the pool or try out a cool new fitness class at the gym? Unless you are an elite runner, the point is just to stay fit, healthy, and happy.
Stay safe this summer and sweat on, friends!