A sauna suit is a tracksuit made of material that doesn’t breathe. It is sold on one promise: sweat more, weigh less.
The name borrows from the sauna, and so do the claims. This article looks at what was measured. It sits under our overview of sauna health benefits. This is general information, not medical advice.
Short answer: a sauna suit makes you hotter and sweatier during exercise. It adds almost nothing to the calories you burn, and the weight you lose is water you will drink back. It has a use in heat training for athletes. For fat loss it isn’t worth the risk.
What a sauna suit does
It blocks evaporation. Sweat can’t leave, so your body can’t cool itself the usual way, and your temperature climbs.
A 2018 study measured this. Ten moderately trained people cycled for 30 minutes in a temperate room, with and without an upper-body sauna suit.
| Measure | No suit | With suit |
|---|---|---|
| Core temperature rise | 1.3°C per hour | 1.7°C per hour |
| Sweat rate | 0.56 liters per hour | 0.89 liters per hour |
| Peak heart rate | 151 beats per minute | 155 beats per minute |
The authors’ summary: exercising in the suit “induces a greater physiological strain and evokes larger sweat losses.”
So the suit does what it says. You sweat about 60% more, by my arithmetic from those two sweat rates.
What it doesn’t do: burn many more calories
A 2022 study tested the weight-loss claim directly. Twelve recreationally active adults did the same high-intensity interval workout twice, once in a sauna suit and once without.
Energy use during the workout was 285 calories with the suit and 271 without. Afterward it was 123 against 113.
The authors’ conclusion: wearing the suit “elicits greater EE vs. not wearing a sauna suit, but the increase of 23 kcal may not benefit weight loss.”
One finding went the other way: fat oxidation was higher for an hour after the suit workout. The authors still landed on the conclusion above, and one small study of 12 people isn’t a basis for a product purchase.
Where the scale number comes from
In the 2018 study the suit added about a third of a liter of sweat per hour. That much water weighs about 0.7 pounds. The arithmetic is mine: 0.33 liters of water is about 0.33 kilograms.
It is water. Cleveland Clinic’s Dr. Amy Zack said it about saunas, and it applies here: “you will lose water weight, but that is not weight loss, that is dehydration.”
Drink a glass of water and the number is back.
The one legitimate use
The 2018 study points to it. In hot conditions, the suit raised strain further, “which may accelerate the stimuli for heat adaptation.”
Athletes preparing for a race in the heat sometimes train this way, under supervision, to get their bodies used to it. That is heat training. It isn’t weight loss, and it isn’t for beginners.
The risks
You are deliberately blocking your body’s cooling system. The dangers follow from that.
- Overheating. Core temperature rose faster in every suit condition tested.
- Dehydration. More sweat lost, and you can’t see it evaporating to judge how much.
- Fainting, especially if you are also cutting food or water.
My own safety advice, since the studies don’t give a protocol: never wear one in a sauna or hot tub, never in hot weather without building up slowly, keep sessions short, drink water, and stop at the first sign of dizziness, nausea, or a headache. People with heart or blood pressure conditions, and anyone pregnant, should not use one without a doctor’s advice.
Sauna suit or sauna?
They aren’t substitutes. A suit is a training tool worn while moving. A sauna is a place to sit still in the heat.
If what you want is the sauna experience at low cost, a portable infrared unit is the closer match. The HigherDOSE Infrared Sauna Blanket costs $699 and the Sunlighten Solo Dome $1,999. Neither is a weight-loss device either. The home sauna buying guide covers full cabins.
Bottom line: a sauna suit sells sweat, and sweat isn’t fat. The measured calorie difference was 23. Skip it unless you are an athlete doing supervised heat training.
Sources
- Matthews ARD, Astorino TA, Crocker GH, Sheard AC, “Acute Effects of High-Intensity Interval Exercise While Wearing a Sauna Suit on Energy Expenditure and Excess Post-exercise Oxygen Consumption,” Journal of Strength and Conditioning Research, 2022 (abstract): pubmed.ncbi.nlm.nih.gov
- Willmott AGB, Gibson OR, James CA, Hayes M, Maxwell NS, “Physiological and perceptual responses to exercising in restrictive heat loss attire with use of an upper-body sauna suit in temperate and hot conditions,” Temperature, 2018 (abstract): pubmed.ncbi.nlm.nih.gov
- Cleveland Clinic, “Get Your Sweat On: The Benefits of a Sauna,” August 12, 2024: health.clevelandclinic.org
- HigherDOSE and Sunlighten listings (price), checked September and October 2026