It’s not unusual to get a little sweaty while you’re exercising. It can even feel good to work up a serious sweat by the end of a particularly tough workout. But the latest fitness trend may make you break a sweat before you even get moving.
Heated workouts—like hot yoga and hot Pilates—claim to boost flexibility, make your heart stronger and sweat out toxins. Some people love them, others feel like it’s just a lot of hot air.
“As hot workouts become more popular, we’re also starting to see more people who experience negative effects from them,” says Joseph L. Medellin, M.D., a sports medicine physician at Henry Ford Health. “If you’re going to try them, you do need to take some safety precautions.”
What Are Heated Workouts?
You may see them called “hot workouts,” “heated workouts” or “infrared workouts.” Regardless of the name, the idea behind them is the same. Expect to be doing your exercise in a room that’s heated to anywhere from 80 to over 120 degrees Fahrenheit.
The trend likely took root in yoga studios. Bikram yoga has been around since the 1970s and is typically done in rooms heated to 105 degrees and a humidity level around 40%. More forms of hot yoga soon followed suit.
More recently, the heat has moved into other types of workouts. You’ll now find gyms and studios turning up the heat for hot Pilates and even hot sculpting and heated high-intensity interval training (HIIT) classes.
Traditional hot workouts use regular heat to increase the temperature (and often the humidity levels) in the room. A newer approach uses radiant, infrared panels to create a dry heat. That makes the environment of an infrared workout more like a sauna than a steam room.
Are Hot Workouts More Effective?
The answer to this depends partly on who you ask. “Some people just like the idea of sweating and the ‘detox’ feeling they get from it,” says Dr. Medellin. “But the evidence for that is primarily anecdotal, not objectively supported by strong evidence.”
Proponents of hot workouts say that exercising in extreme heat makes them feel more warmed up, flexible and better able to move easily. And while it makes sense that warmer muscles are more pliable, there’s limited research to back up the benefits of a hot gym session.
The real benefit of working out in the heat is that it helps the body adapt to working out in the heat. “If you’re an athlete training for a competition in a very hot climate, it’s important to acclimate before the event,” says Dr. Medellin. “There is data that supports how mimicking a hot environment can help your body adapt in advance. And that can be crucial for performing better in the heat.”
Possible Hazards of Hot Workouts
Sitting in a hot sauna can feel relaxing, but doing high-intensity exercise in one has very different effects.
Working out in the heat can increase your heart rate and make your heart work harder. That can increase your blood pressure and put extra stress on your heart.
Increased sweating during a hot workout means you’re losing more water. Losing excess fluid can leave you dehydrated.
It’s also possible to experience heat illness when doing hot workouts. This occurs when your core body temperature rises faster than the body is able to cool itself. If you do hot workouts, be on the alert for signs of heat stroke, including:
- Cramping
- Dizziness
- Headache
- Nausea or vomiting
- Racing heart rate
“Heat stroke is a medical emergency,” says Dr. Medellin. “Luckily it is very easily treated if you seek help promptly.”
Who Should Avoid Hot Workouts
Despite their current popularity, heated workouts aren’t for everyone. “Anyone with heart disease or a condition that makes it hard to regulate body temperature should avoid hot workouts until they consult with their primary care physician or cardiologist,” advises Dr. Medellin.
You should also avoid hot workouts (or at least consult your physician before trying one) if you are:
- An older adult
- Pregnant
- Not in good shape or haven’t exercised in a while
- Someone with a neurological condition (including multiple sclerosis), diabetes, obesity or a heart condition (such as high blood pressure or arrhythmia)
How to Make Hot Workouts Safer
Hot yoga, hot Pilates or an infrared HIIT workout are generally considered safe for young, healthy adults. But everyone should take precautions to ensure they’re working out safely.
“The most important thing is to make sure you are well-hydrated—and have a plan to maintain your hydration during the workout and recovery period,” says Dr. Medellin. He recommends bringing water or an electrolyte beverage with you to drink during class. “You don’t want to get too far behind on your fluid intake,” he says.
After your workout, you’ll want to continue to focus on rehydrating. “Be very cautious with alcohol, which can further dehydrate you if you haven’t fully replenished yourself,” says Dr. Medellin.
He also recommends skipping your hot workout if you’re sick. “Your body is already working overtime to clear the infection,” he says. “Getting your heart rate up and getting more dehydrated can slow recovery.”
Whether you enjoy a relaxing heated yoga class or want to sweat it out in an infrared HIIT session, with a little planning, you can do it safely.
Reviewed Joseph L. Medellin, M.D., a primary care sports medicine doctor at Henry Ford Medical Center - Jackson.
