The latest research, however, suggests that these scuba-style outfits might just have some legit workout perks.
Lance C. Dalleck, Ph.D. and an ACE Scientific Advisory Panel Member, recently found that training in sauna suits can have serious performance benefits for athletes. “We know that for athletes who train in the heat, there are a number of adaptations,” says Dalleck. “You sweat earlier, you have an increase in plasma volume, have a higher VO2 max and better ability to tolerate heat.”
But in his most recent study, Dalleck wanted to see how exercising in sauna suits would affect weight loss.
The research team from the High Altitude Exercise Physiology Program at Western State Colorado University recruited 45 sedentary overweight or obese adults between the age 18 and 60 years old with a BMI between 25 and 40, a body fat percentage over 22 percent for men and 32 percent for women, and rated as low-to-moderate risk for cardiovascular, pulmonary, and/or metabolic disease. They were divided up into three groups: a sauna suit exercise group, a regular exercise group, and a control group.
For eight weeks, both exercise groups participated in a progressive workout program, performing three 45-minute moderate-intensity workouts (elliptical, rower, and treadmill) and two 30-minute vigorous-intensity workouts (spin class) per week. They all ate normally and didn’t do any exercise outside of the study’s guidelines. The only difference between the two groups? One group worked out in Kutting Weight sauna suits (a thick Neoprene garment similar to a wetsuit) while the other group worked out in their usual gym clothes.
The benefits of sauna suits for weight loss
At the end of the trial, all exercisers saw improvements in systolic and diastolic blood pressure and total cholesterol as well as a decreased waist circumference. (Yay!) But, TBH, that’s not really groundbreaking. (You can get pretty awesome physical benefits from just one workout.)
What is interesting, however, is that the sauna suit group saw a greater improvement in basically every key measure over those who exercised in regular clothes. For one, the sauna suit group dropped 2.6 percent of their body weight and 13.8 percent of their body fat versus the regular exercisers, who only dropped 0.9 percent and 8.3 percent respectively.
The sauna suit group also saw a greater improvement in their VO2 max (an important measure of cardiovascular endurance), increase in fat oxidation (the body’s ability to burn fat as fuel), and a greater decrease in fasting blood glucose (an important marker for diabetes and prediabetes).
Last but certainly not least, the sauna suit group also saw an 11.4 percent increase in resting metabolic rate (how many calories your body burns at rest) compared to the regular exercise group, which saw a 2.7 percent decrease.
It all comes down to EPOC, or post-exercise oxygen consumption, says Dalleck. (That super awesome thing behind the “afterburn effect.”) “Exercising in heat increases EPOC,” he says, “and there are a lot of favorable things (like burning more calories) that come with EPOC.”
There are a variety of factors that can increase EPOC: for one, high-intensity exercise because it creates a larger disruption of your body’s homeostasis. After exercise, it takes more energy and effort to return to that homeostasis. Another factor: the disruption of your normal core temperature. All exercise results in an increase in core temperature, but if you accentuate that even more (for example, working out in the heat or in a sauna suit), that means it’s going to take longer to return to homeostasis and regulate your body temp. Both of those things result in a greater calorie burn and improved carb and fat oxidation.
Before you go work out in a sauna suit…
Note that the study was conducted using only moderate-to-vigorous intensity exercise, but not high intensity, and always for 45 minutes or less, in a controlled, unheated environment. “In this instance, if used appropriately, sauna suits can be very beneficial,” says Dalleck.
That being said, subjecting your body to heat and a super intense workout when you’re not trained for it can put too much stress on your body and result in hyperthermia (overheating). “We recommend keeping the intensity moderate to vigorous, not high,” he says. Another important note: If you have diabetes, heart disease, or any other conditions that make it difficult for your body to thermoregulate, you should skip the sauna suit or check with your doc first.
Plus, you might be able to get the perks from just going to your usual heated spin class, vinyasa, or other steamy workout studio. The sauna suits simulate about a 90-degree Fahrenheit environment with 30 to 50 percent humidity, says Dalleck. Though you can’t exactly control the environment of your workout class to a T, challenging your body to adapt to that environment is similar to heating it via sauna suit. (See: Are Hot Workouts Really Better?)
One last interesting perk: “Acclimating to one environmental stressor can offer protection against other environmental stressors,” says Dalleck. For example, acclimating to heat can help you acclimate to altitude.
Have a big hiking trip coming up or ski vacaction? Consider sweating it out before you head up the mountain—you may get a whole bunch of body perks (and breathe easier up there) because of it.