That leaves many turning to the great outdoors — yet, it doesn’t always feel so great when the temperature hits 90 degrees. Exercising in the heat is tough.
“We get rid of heat through the evaporation of sweat, and so if it’s really hot outside, that process is slower and your body has to work harder,” says Patrick Davitt, program director of health sciences at the University of the Sciences.
That doesn’t mean you should skip your workout. With a little mindfulness, you can still get your fitness on, and do so safely.
“Times are crazy right now, so it may be even more important to get out there,” says Davitt. “There’s a lot of mental benefits to exercise.”
The most important thing you can do is take time to acclimate your body, says Alexis Tingan, a sports medicine doctor at the University of Pennsylvania.
“We recommend using a two-week period to ease into the heat, so starting with a one-mile jog instead of three, and slowly amping up,” he says.
Because we have to wear masks in public, consider further lowering your intensity. Masks, too, will require an adjustment period, but both become easier over time, Tingan says.
Wearing a mask has an impact on your workout.
“It’s harder to breathe, but when you’re the one that’s doing the heavy breathing, a mask is definitely something you need so you don’t infect everyone else,” says Ross Martinson, Philadelphia Runner owner and elite athlete coordinator for the Philadelphia Marathon.
“Always err on the side of caution — even with the buff, cross the street whenever you can [when someone’s coming],” says Suzanne Allaire, cofounder of November Project Philadelphia and 15-time marathon runner.
Temperatures peak between 10 a.m. and 3 p.m. Plan to avoid that window, ideally by several hours.
“It’s coolest between midnight and sunrise, so try to get out there before 7 a.m.,” says Tingan.
Rolling out of bed might not feel easy, but the earlier you do so, the fewer people you’re likely to encounter. For motivation, Allaire recommends setting your clothes out the night before and finding an accountability partner. With the pandemic, this can simply mean texting a friend to tell them your plans.
“Sometimes I’ll turn to social media and tweet that I’m going to get up and run. Other people will chime in, and we’ll check back in with each other,” says Allaire, adding that coffee can help, too. “We also just got this programmable coffee pot — when I smell the coffee, it makes me want to get up.”
While 90 degrees might sound hot, it’s actually humidity levels to which you want to pay closest attention. Remember, your body cools itself down when your sweat evaporates, and humid conditions make evaporation harder.
“In high humidity, the sweat just stays on your skin, so your body has to work on overdrive,” says Tingan.
Since evaporation is key, wiping sweat off with a towel isn’t going to help. Don’t let a cloudy day trick you, either. If it’s extra humid, cloud cover won’t make much difference.
Going into a summer workout dehydrated is one of the worst things you can do, experts say. Drink water throughout the day, not just before heading out. And remember, most public water fountains are currently out of commission, so plan ahead.
“The eight glasses of water rule a day is not the end-all-be-all, but it’s a good rule of thumb,” says Tingan.
A good hydration test is to check the color of your pee. It should look like a light lemonade. If it’s darker, drink more.
For longer workouts, consider weighing yourself before and after.
“If you weigh 180 pounds right before, and you’re 175 after, you just lost five pounds of water weight,” says Davitt. “Every pound is 16 ounces of water, and ideally you want to replace that within the next few hours.”
We lose electrolytes — essential minerals like sodium, calcium, and potassium — in our sweat. If exercising for more than an hour, refuel your electrolytes while working out.
In the summer, cotton is not your friend.
“It holds water, which makes it not only harder to cool off, but more likely for you to blister and chafe,” says Martinson.
Instead, go for fabrics labeled moisture-wicking, often found on spandex, polyester, or other synthetic-crafted clothes. These are quick-drying, sweat-absorbing materials.
Even with those, less is better.
“You want a large surface area for sweating and evaporating, so the more of your skin that’s exposed, the better,” says Tingan.
If you feel comfortable, workout in a sports bra or go shirtless. For a T-shirt, choose light colors, which reflect heat from the sun. And don’t forget sunscreen.
Pavement absorbs light and radiation and emits it as heat, so stick to sidewalks or grass when possible. Better yet, hit a trail an hour or two away from a city, where temperatures are almost always cooler. Cities have more buildings and roads, which absorb heat from the sun, and fewer plants, which cool the air.
The pandemic has fueled an inspiring number of new runners. But jogging isn’t the only way to work out outdoors.
“I’ve been doing a lot more biking, which is great cross-training and creates a little more wind against you in the heat,” says Allaire. “It’s also easier to carry more hydration and snacks.”
While the city’s public pools are closed, swimming is one of the best summer workouts if you can find a place to go. And never underestimate YouTube, which offers a library of workouts, from yoga to body-weight classes, to try outside or in your air-conditioned home.
“If you don’t own weights, a gallon of water weighs 8 pounds, so put a gallon in each hand,” says Davitt. “Or you can get a 40-pound sandbag at Home Depot for $5 — one of the greatest and cheapest workout tools.”
Fill a water bottle halfway and freeze it overnight. Top it off before you head out for your workout.
“Evaporation is the main way we lose heat, but the other one is conduction — if you touch something cold, it’ll pull the heat away from your body,” says Davitt.
If parts of your body start to cramp or you get a headache, you may be nearing your limits. Other signs include feeling weak, light-headed, nauseous, clammy, cold, and pale. If these symptoms occur, stop immediately, and try to cool yourself off.
“Find shade, hydrate if you have water on you, and if you’re near home, go home and get by a fan, which will help the [sweat] evaporation process,” says Tingan.
Most experts say that as long as you’re healthy, the climate around Philly almost never reaches a point where you shouldn’t exercise outside.
“There’s not a hard and fast rule, but use common sense,” says Tingan. “If it’s super hot, go for a walk, and avoid the hard workout.”
If you have an underlying condition, always consult with your doctor first.
Listen to your body. Heat and humidity may require you to decrease your intensity and volume, and there’s no shame in that.