There is a ton of misinformation in the fitness industry in general, and one of the places where information gets distorted has to do with saunas. Time in the sauna feels great and offers health benefits, but some sources vastly over exaggerate the idea that you can lose weight in a sauna. Some claim that there are anywhere from 300-1000 calories burned in a sauna session of 30 minutes.
Doesn’t that sound nice? You get to kick back on your bum in a hot room for 30 minutes and use an average of 10 to 33.3 calories per minute? You/we wish!
If you have ever watched the readout on a treadmill or pushed yourself through a tough HIIT workout, you’ll know that burning a rate of even 14 cals per minute is extremely high and hard to sustain. So what makes people think that you burn such a high rate of calories by sitting in a sauna?
They claim that your body has to struggle to maintain it’s preferred temperature, which causes the metabolism to kick into overdrive, thus using calories. There is truth to that but in no way would that ever cause you to use any more than double the rate of calories for doing exactly what it is that you do in a sauna or steam room; sitting.
How many calories are burned in a sauna?
Here’s an equation you can use to estimate out how many you’re burning:
Number of calories burned in 30 minutes of sitting (specific to your bodyweight) x 1.5 (possibly x 2) = calories burned
For example, a healthy male of 185 pounds burns 42 calories in 30 minutes of sitting. To find the number that this same individual burns while sitting in a sauna, multiply those calories by 1.5 and 2 in order to get an estimate. In this case, the individual would burn roughly 63 to 84 calories. That’s a huge difference from the 300 to 1000 estimate!
Can You Lose Weight in a Sauna or Steam Room?
Yes. But you’re not building muscle, you aren’t burning a significantly raised rate of calories, and you’re really only losing water weight. In addition, not replacing the water you are sweating out can actually make it harder for your body to lose weight.
The weight that you lose while you sit in a sweltering room is purely water, water that you should be replacing as fast as you are losing, otherwise you are just severely dehydrating your body. Not practicing proper hydration while you’re in one of these hotboxes is unhealthy and actually makes it tougher for your body to lose pounds permanently, as hydration is an essential component in shedding extra weight.
Really, you wouldn’t even want to use a sauna for weight loss even in the most temporary instances. For example, if you are trying to lose weight very quickly for an event or to squeeze into a particular dress, you would feel (and maybe even look) terrible if you had used a sauna to drop those last few pounds before the event without rehydrating your body after the sweat session. Consistent, moderate healthy habits are key to losing weight and keeping it off; try your best to avoid extremes and quick fixes as they're usually either a scam, not healthy, or not sustainable long term.
The truth is…
You’re much better off with real exercise. You create a true temperature regulation/metabolic boost effect on your body while exercising; when you push your body into strenuous physical activity, your metabolism is stoked as it tries to regulate body temperature, AND all of your muscles are called upon to function in unison, and your heart rate is elevated. That burns calories! Far more than sitting in a hot steam room or sauna. High intensity interval training (HIIT) and strength training are excellent, scientifically backed methods of increasing your metabolism - albeit slowly & marginally, but these things add up over time.
There’s no problem with joining the leagues of people who make sitting in a hot box a fundamental part of their regular workout regime, in fact, there are health benefits to be gained from it. I know for me, it ends up feeling very relaxing. Just make sure that your main objective is not solely to lose weight; the calories burned in those sitting sessions are not substantial, you aren’t burning fat, and you are not building muscle.
Enjoying a sauna or steam room properly (and with approval from your doctor) is not a bad addition to a fitness routine and it can be very enjoyable and serve as a bit of a treat after a particularly demanding workout. Just don’t erroneously believe that it’s attributing a noteworthy amount of calories burned to your total or that it’s going to help you lose any weight that you wont re-drink in the next hour or two.