How to Work Out Safely When It’s So Darn Hot Outside

We’ve finally got the sunshine we’ve been waiting for, so make the most of it by taking your workout to the great outdoors. Studies have shown that exercising outside can be more effective than using machines, since running or cycling over naturally shifting terrains works a greater variety of muscles. But get 10 minutes into a workout when it’s 85°F and humid, and you might find yourself missing the air conditioning. Don’t give up yet! Here’s how to work out safely and successfully when it’s hot.

Take it slow

As tempting as it is to race out into the sunshine, it’s best to take it easy. The first few times you work out in hotter-than-usual weather should be about acclimatizing to the heat. Meghan Stevenson, a certified coach with the Road Runners Club of America (RRCA) in San Francisco, CA who has an online training company called Your Best Run, explains that heat affects everyone differently, so it takes us all different amounts of time to get used to summer weather. “If you grew up in a hot and humid area, for example, you might tolerate heat better. That being said, it takes at least a few days to acclimate, and longer to perform at your best — maybe a few weeks, or even a couple of months,” says Stevenson.

Rather than trying to keep up with the pace you can hit in ideal conditions, Stevenson recommends listening to your body and adapting your expectations. “Running 30 to 90 seconds slower per mile than your regular easy pace is pretty normal, especially if it’s humid too. Above all, you need to stay healthy, so if you’re feeling something unusual, like lightheaded or extra crampy, ease up, get in the shade or air conditioning, drink water, and maybe come back to it another day,” she advises. As much as we love the satisfaction of setting a personal best, your health should always take first place, so be prepared to change your fitness goals to suit your body’s needs in the heat.

Dress in Less

What seems like a moderately warm day when you’re strolling around can quickly escalate to fried-eggs-on-the-tarmac hot when you start working out, so dress as though it’s about 20°F warmer than the actual temperature. Stevenson is a big advocate for joining the men in going shirtless (check out her hashtag #SportsBraSquad for inspo/courage), but if you want to wear a top, she has another useful cooling tip: “Wet down your hair and shirt before you go. It will help cool your body right from the start.” It might seem extreme, but you’ll be grateful going into your third mile!

Stay hydrated

Dehydration is never fun, but it’s especially important to stay hydrated when it’s hot, both for your performance and your health.

Unsurprisingly, experts recommend drinking lots of water throughout the day — not just right before you leave — as the best way to ensure you’re ready to go. But how much do you actually need? Meghan Kennihan is an RRCA distance running coach, USA Cycling coach, USA Track and Field running coach, and a personal trainer certified through the National Academy of Sports Medicine (NASM). When she’s not training others in Western Springs, IL, she’s a triathlete, marathon runner, and powerlifter. She says that if you want to get super geeky (and maximize your workout), you can use an online calculator to find out how much fluid you personally lose while exercising, depending on factors like humidity and temperature, and how much you naturally sweat.

There is another, much quicker way. Jeff Miller, a personal trainer certified through the International Fitness Professionals Association (IFPA) who is based in Albany, NY, says, “If your pee is clear and not yellow, you’re good to go. You can’t really be more hydrated than that — you’re not a camel! That’s what water bottles are for.”

Getting dehydrated halfway through your running route will really ruin your day, so make sure you have access to water while you’re out. Either plan a route with a good supply of water fountains, or carry a bottle or two with you. Look for a belt with space for lightweight bottles, or a holder that straps around your arm. It might be annoying at first, but you’ll forget all about the extra weight once you’re thirsty!

Recover right

What you do once you’ve finished is just as important for your health as your pre-workout routine. Kennihan explains, “Studies have indicated that post-exercise nutrition can be critical for muscle recovery, restoration of glycogen stores, and ultimately for maximizing performance and endurance. Heat makes workouts harder on your body, so it’s especially important to focus on recovery on hot days.”

After your workout, not before, is the time for those fancy sports drinks (as well as more water). Stevenson says that these are terrific at replacing the water and electrolytes you lose through sweat. Electrolytes are chemical elements and minerals that aid hydration; without electrolytes, the water you’re drinking won’t get to the cells that need it.

If you’re not keen on the sugar and chemicals some of these drinks contain, Miller suggests simply adding “a pinch of Himalayan salt to your water. It has lots of good minerals and no artificial coloring or flavoring. And, as always, eat lots of fruits and veggies.”

How hot is too hot?

The best way to figure out whether it’s safe to work out outside is by looking at the heat index using the National Weather Service’s heat index table or calculator. This combines the air temperature and humidity to show you how hot it actually feels, and the level of risk associated with being outside.

For example, if it’s 88°F with 70 percent humidity, the heat index is 100°F, which is considered cause for “extreme caution.” It’s worth noting that the heat index is based on the temperature in the shade, with a gentle breeze — factoring in direct sunlight can add another 15°F to the feels-like temperature. If the heat index is forecast to exceed 105-110°F for at least two consecutive days, the National Weather Service will likely issue a warning, but Miller cautions that any heat index in the triple digits is cause for caution.

Focus on the long-term benefits

If being forced to take it easy is frustrating, the good news is that training in hot weather can improve your performance long-term. Kennihan says, “Working out in hot conditions for about two weeks can make it easier to maintain a faster pace, increase blood plasma volume so you cool down faster, and reduce your heart rate at a given pace and temperature, so you’re working more efficiently. It’s especially important to practice in the heat if you’re going to be competing outside.” Be sensible, be safe, do the best you can in the given conditions, and enjoy the benefits of the extra-hard work when the weather cools down again.

Are you happy to be working up a sweat in the sunshine? Share your hot weather workouts @BritandCo.

(Photo via Getty)