A few years back, I attended Bikram yoga on a regular basis. 6 am classes? Yep. I was there. Weekends? Of course. I loved it. In my opinion, Bikram is the athlete's yoga. After years of pushing myself to my physical limits in the pool, this type of yoga suited me perfectly. No relaxation, no zen, no Om, just pushing my body to the physical limit. (Yoga is defined as "Unity"; connection of the body and mind).
Bikram is a type of yoga done in a room heated to 105 degrees with 40% humidity. The practice is a series of 26-poses, done twice, and always in the same order. Every single Bikram class is the exact same as the last and once you take a few classes, you know which pose is coming up next before the teacher gets the words out of their mouth.
I've grown out of the "all Bikram, only Bikram, all the time" phase (although I still continue to practice yoga on a regular basis) but took one the other day and started thinking about sweat ratio vs. calorie burn.
Every single person who walks out of a hot yoga class is drenched, as in, "it looks like they've walked through a sprinkler" drenched. When I was taking the class often, I thought that I was burning a ton of calories. It made sense, right? Drenched in sweat means a HUGE calorie burn, therefore, in the long run, weight loss!
Sadly, I was wrong. This just isn't the case.
Sweat is simply our body's way of cooling down our core temperature, as well as ridding the body of toxins. Unfortunately, sweat does not equal calorie loss. You will lose approximately the same number of calories during a yoga class, whether done in a heated room or a non-heated studio. (Although the type/style of yoga does provide some variance. A more passive class, such as restorative yoga won't burn as many calories as a Vinyasa/Flow class). HealthStatus.com reports that for one hour, a 150lb person can lose 180-594 calories, depending on the class, with Vinyasa being the style with the greatest calorie burn). Burning calories, and therefore losing weight, happens through energy expenditure, not simply sweating.
Here is a great explanation on calorie burn from Dr. Olsen, an exercise science professor from Auburn University "To warm our bodies, our muscles will perform extra small and rapid contractions that are usually not felt, but anytime your muscles contract more, they use extra calories. Heat is released every time a calorie is burned — and this is what helps keep the body's core temperature up and stable. Sometimes the twitching is very noticeable and we call it shivering. But, the process of sweating does not require active calorie burning.
So, don't rely on sweat as a sole gauge of exercise intensity. A combination of heart rate and perceived effort are much better indicators of how hard you are working and how much energy you are expending."
Yes, you will weigh less coming out of a hot yoga class compared to when you went in, but that's simply water weight and once you replace those fluids, your body will register the same number on the scale as before you went to class.
The best way to lose weight? Mix up your workouts and eat (mainly) healthy foods. Include yoga in your regimen, but make sure there's cardio and strength work to keep your body strong, flexible and fit! How do you stay healthy?