Committing to your running routine is easy when the birds are singing, the sun is shining, and there's a slight breeze to cool you off. But as the temps get hotter and humidity levels rise, even the most dedicated runners need to adjust their game plan. After all, running in hot weather can be a major slog, especially if you live in an area that experiences high humidity and scorching temps.
Instead of letting your running shoes gather dust in the corner or succumbing to only treadmill runs, keep your momentum going by learning how to adjust your run (and your recovery) for hot summer temps. Ahead, we'll examine why running in the heat feels so different from running in cooler weather and what steps you can take to stay safe, hydrated, and injury-free.
No surprise here: The biggest difference between hot weather and cold weather running is that your pace slows down as temperatures rise. No matter who you are and whether you're an ultramarathoner or running your first 5K, research shows all ages, genders, and running levels are affected by these steamy temps. Here's why: When you're running in the heat, your body sends blood to your skin's surface, where the blood is able to spread out and cool down. Once that dissipation occurs, your skin uses evaporation to cool off, which kickstarts the process of sweating. That additional job of sending blood to your skin causes your heart to beat a little faster since it's working extra hard to circulate your blood to a new location.
Eventually, if you get dehydrated, your heart will have to work even harder to keep your blood circulating; you'll also experience symptoms like headaches, dizziness, fatigue, and more. (FYI, dehydration occurs when you lose more fluids than you take in, and your body struggles to carry out its usual, necessary functions.) All that extra work on your heart translates to slower paces as your body compensates for warm weather. Interestingly, while humidity can make hot temperatures feel even more oppressive, it's been shown to have surprisingly little impact on running pace.
Another difference between running in hot weather vs. cold weather is your sweat. Not only do you sweat more in hot weather, but the production of sweat starts earlier in the run than it would in chillier temps. And when you sweat more, you lose more electrolytes — the minerals that help your body maintain the right balance of fluids and absorb important nutrients. If you sweat out more fluid (and more electrolytes) than you're able to replace through rehydration, you could be in danger of heat exhaustion. Heat exhaustion occurs when your body overheats, and it can include symptoms such as goosebumps, a faint pulse, and heavy sweating. At worst, heat exhaustion can lead to heat stroke, a life-threatening condition that can permanently damage your brain and vital organs.
Lastly, running in the heat can impact your cardiovascular system. That's because your higher body temperature makes it more challenging for your body to utilize oxygen, which can affect both your performance and how quickly you become dehydrated or experience heat exhaustion.
You'll need more than good intentions for a safe, successful run in hot weather. After all, you're sweatier, slower, and have less oxygen available; that's not exactly a recipe for success. However, with proper planning and the right gear, you won't have to quit your running habit during the warmer months. The biggest mistakes that runners make in hot weather include wearing moisture-trapping clothing, hydrating poorly, and ignoring the warning signs for heat exhaustion and dehydration, according to experts. Avoid any downfalls by following these tips for a better hot weather run from start to finish.
It might seem like a no-brainer, but the last thing you want to do is make your run as challenging as possible by doing it at the hottest, brightest time of day. "If the weather is hot, try and get out before the sun comes up (or after the sun goes down)," suggests running coach Steve Stonehouse, NASM-CPT and director of education for STRIDE Fitness. "Heat is one thing. Heat and the sun beating down on you is another," he adds.
There's no specific temperature at which to call off your run, although it's advised to pay attention to your local weather service and nix any run based on their advice, notes Stonehouse. Wind can also impact your run. "A nice breeze can help cool things down," he says. "Other times, the breeze is just as hot as the temp and it makes things worse."
It's obviously key to continuously hydrate during a run in the heat, but proper hydration should begin before you lace up your shoes. Starting around four hours before your run, drink water enhanced with electrolytes to get a head start on replenishing what you'll eventually sweat out; that way, you'll maintain the right balance of fluids throughout your run, as Shape previously reported. If you'll be going for an exceptionally long run or you're planning to hang out in the heat afterward, eat something high in sodium in the hours before your run (such as pretzels, cottage cheese, or even just adding a pinch of salt to whatever you're already eating). The goal is to fuel your body with plenty of sodium so that when you inevitably sweat, you'll have sodium to spare. Plus, getting sodium from food (as opposed to only getting it from liquids) helps lower the risk of hyponatremia, aka overhydration, notes Stonehouse.
Save your cotton for another time and opt for quick-drying materials, such as nylon or polyester, when running in the heat. "I always suggest people train in some type of synthetic, moisture-wicking material as it will help keep your skin dry," explains Stonehouse. He recommends avoiding anything that's 100 percent cotton, since that material will retain water and sweat, leading to a damp, uncomfortable run. Not only will moisture-wicking materials help your body stay cool, but socks made out of polyester or nylon will help prevent another common running plight: blisters.
In addition to wearing appropriate clothing, don't skimp on sunscreen to protect your skin from the sun's harsh rays and lower your risk of skin cancer. Cover all exposed areas with at least SPF 30, which is what the American Academy of Dermatology recommends for daily use, as Shape previously reported. Look for a sweat-proof SPF that can stand up to your effort.
While it sounds counterintuitive to pare down your warm-up as it plays an important role in activating your muscles and safely preparing for a good workout, it's acceptable to scale back when running in the heat. "Typically, the purpose of the warm-up is to increase blood flow and prepare a muscle or system to work,"explains Stonehouse. "In warmer weather, the blood flow is already increased, so preparing that muscle or system to work usually won't take as long." He recommends active or dynamic movements pre-workout (such as lunges or squats) over just static stretching (such as touching your toes).
You might be tempted to zone out to your playlist or chat with your running buddy to avoid obsessing over the heat, but you should stay on the lookout for any signs of heat exhaustion or dehydration. Heat exhaustion warning signs include headache, dizziness, muscle cramps, unusually fast pulse, and feeling queasy or nauseous. Dehydration symptoms include extreme thirst, dizziness, irritability, dark or concentrated urine, and dry lips, mouth, and/or eyes. If you notice any of these symptoms, don't try to power through — it's much safer to stop immediately, cool down, and hydrate.
While carrying a water bottle or stopping for breaks during your run may be a pain, it's a must when running in hot weather. "The thicker your blood is, the harder your body has to work to push it through the [circulatory] system," advises Stonehouse. Hydrating throughout your run will prevent your blood from thickening. "The more hydrated you are, your blood is thinner and will circulate much easier," he adds. And when your blood circulates smoothly, your muscles get the oxygen they need to power through that last distance without getting too winded.
If you're concerned about holding a slippery water bottle in your hand while you sweat all over it, rest assured that there are alternatives. For quick, easy access to your water, try a handheld water bottle that straps to your palm. Or if you can't stand holding anything while running, wearable running vests help you hydrate hands-free. Experiment with a few different water bottle alternatives to see what's the most comfortable and functional for you.
Cool down with static movements and thorough stretching after hot weather running, advises Stonehouse. Focus on your hamstrings, calves, hips, and quads for a faster recovery (your legs will thank you for the TLC).
Additionally, consider taking the plunge into cold-water immersion, which can speed up recovery, according to Stonehouse."Jump in the pool, take a cold shower or even an ice bath... anything to help drop your body's core temperature faster is great," he says. By dropping your core temperature, you'll avoid that dreaded heat exhaustion and return to your usual body temperature safely.
Your run may be over, but your hydration should continue. Prioritize drinking electrolyte-enhanced water in the hours after your hot weather run to replenish what you lost through sweat. You'll also get other added benefits of electrolytes; for example, the electrolytes potassium and magnesium can help prevent muscle cramps.
In addition to rehydrating with electrolytes, you may find that you're craving salty foods after a particularly sweaty run. If so, consider this a chance to practice intuitive eating. This particular craving is your body's way of alerting you that it needs those electrolytes back ASAP — so go ahead and reach for sodium-rich foods such as a handful of nuts, canned fish, or even a sushi roll with soy sauce.
Even though the temperatures may be high, you can still get your miles in. By hydrating properly pre-run, replenishing lost electrolytes, and wearing heat-friendly, moisture-wicking clothing, you'll be able to take on your summer running goals with confidence.