Oppressive heat can make you sluggish, but it’s a poor excuse for skipping exercise — even if you usually work out outdoors. You just need to smart about it.

“The most important thing to do is 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 1-mile jog instead of 3, and slowly amping up.”

Temperatures peak between 10 a.m. and 3 p.m., so plan to avoid that window, ideally by several hours. From tapping local meetup groups to finding cooler climes, here are some other tips to consider for your summer workout.

Does working out in the heat burn more calories?

When exercising in the heat, your body has to work even harder to cool itself, making a run or a routine feel more challenging. But does it burn more calories, too?

Unfortunately, the answer is almost always no. “If you maintained the exact same pace at 90 degrees as you do at 60, you would burn more,” says Penn sports medicine doctor Alexis Tingan. But “most people decrease intensity and volume because heat is hard for the body to handle, so, you end up burning about the same amount.”

Gear up with heat-friendly apparel.

To stay cool, avoid cotton at all costs, says Takia McClendon, apparel buyer for Philadelphia Runner.

“Cotton holds onto moisture, so it’s going to weigh you down, show all of your sweat, and cause chafing.”

Instead, seek out fabrics labeled “100-percent moisture-wicking,” often found on spandex, polyester, or other synthetic-crafted clothes. These are quick-drying, sweat-absorbing materials. McClendon’s favorite summery picks are the Oiselle Pocket Joggers (with five pockets) for women and the Vuori Kore Shorts, made from highly stretchable yet stylish material, for men.

Hydrate smart.

To steer clear of dizziness, nausea, cramps, and other crippling side effects of dehydration, keep a water bottle with you well beyond your workout.

“When we start feeling thirsty, it’s already too late,” says Karin Richards, department chair of kinesiology at West Philadelphia’s University of the Sciences.

How much to drink varies by person, Richards says. The “eight-glasses-per-day” rule is not suitable for everyone.

“I know it’s a little TMI, but the bathroom is your best indicator,” says Richards. “Your pee should look like a light lemonade. If it’s darker, drink more. If it’s completely clear, you might be over-hydrating, which can throw off your electrolyte balance.”

When choosing a drink, stick to water. Tingan points out that beverages like Gatorade can actually decrease performance.

“Sports drinks have a lot of sugar, which can make you sluggish, and they actually don’t have enough electrolytes to adequately replace your loss,” says Tingan. “Instead, drink water and eat a salty snack, like nuts.”

Join an early-morning fitness class.

Need a little external motivation to work out? Go to a free morning meetup to knock out your exercise before the day heats up.

November Project Philadelphia meets twice a week at 6:25 a.m. for group workouts offered for free.
Photo courtesy November Project Philadelphia
November Project Philadelphia meets twice a week at 6:25 a.m. for group workouts offered for free.

November Project — featuring 40-minute, run-based routines with body-weight exercises — kicks off among the earliest at 6:25 a.m. Every Wednesday, anywhere from 80 to 200 participants sprint up the Art Museum steps, pausing on the platforms for push-ups, lunges, and jump squat. On Fridays, the group travels to other locations, like Franklin Field and Washington Square. Check their Facebook page on Thursdays to find out where they’ll be.

“It’s a great way to meet people. The Facebook group is always full of posts from those in search of partners on our off days, too,” says November Project coleader Vinny Carrano.

For a more relaxing start, roll out your mat for Yoga on the Pier, at Race Street Pier, inviting you to move through sun salutations at 7 a.m. Monday through Friday (and 9:30 a.m. on Saturdays and Sundays).

If you prefer to take a spin, try Bicycle Club of Philadelphia, a platform for group rides organized as early as 7 a.m. On weekends, many local bike shops host rides, like the 8:30 a.m. Saturday road ride from South Street’s Bicycle Therapy and the 9 a.m. Saturday (road) and Sunday (mountain bike) rides from Cadence in Manayunk. Check in with each organizer for mileage and pace.

Walkers can get their steps in with We Walk PHL, meeting at 7 a.m. in multiple locations. Check the group’s Facebook page for monthly schedules.

Go for a swim in one of Philly’s public pools.

Swimming is easily one of the best summer workouts: “It’s low-impact, and the water is almost always naturally cooler than the temperature outside,” Richards says.

Philly is home to more than 60 public pools, all of which are free. For a long-distance swim, head to Kelly Pool (4231 Landsdowne Dr.), featuring three Olympic-length lap lanes.

Residents swim at Kelly Pool in Philadelphia, Pa.
Olivia Sandom
Residents swim at Kelly Pool in Philadelphia, Pa.

Or partake in a nighttime ride.

Prefer to cycle after the sun goes down but don’t feel safe flying solo? Head out on a group ride. Both Philly Bike Party and Night Cycle Philadelphia host monthly 8 p.m. rides departing from the Art Museum steps. The 10- to 15-mile routes travel through city streets and/or bike paths, and sometimes end with tacos, a picnic, drinks, or even mini golf. Philly Full Moon Bike Ride also takes off once a month from the Art Museum, usually at 9 p.m., and CycleScenePHL hosts nighttime excursions, too. Follow the respective groups’ Facebook pages for meeting locations and times. Helmets and bike lights are strongly encouraged.

Take a hike.

For a weekend workout that’s more fun, consider venturing out to a trail an hour or two away, where temperatures are almost certainly cooler than in the city. On the hottest day of the year so far, for example, Philly reached 94 degrees — whereas Valley Forge was five degrees cooler and almost 10 degrees cooler at Ricketts Glen State Park in Benton, Pa.

Even within city limits you can find refuge on shaded trails, like those in Wissahickon Valley Park. According to the National Oceanic and Atmospheric Administration, temperatures in shaded areas outside of Center City can be as much as 10 to 15 degrees cooler, and feel even cooler post-rain.

During a hike in Wissahickon Valley Park, you may also find opportunity to take a dip.
ELIZABETH ROBERTSON / Staff Photographer
During a hike in Wissahickon Valley Park, you may also find opportunity to take a dip.

Try a free class at a fitness studio.

Want to work out in air-conditioning but not to commit to a gym membership? Try out one of Philly’s boutique fitness studios. Many offer free first-time class deals, including Flywheel, CKO Kickboxing, CorePower Yoga, The Wall Fitness, Orangetheory Fitness, Cycle Brewerytown, Roots Athletics, Torque, and Pure Barre. Some gyms offer free introductory days or weeks, too, just in case you want to give one a try.