How many calories do you think an hour of hot ashtanga yoga burns?? Online calculators show really high numbers....is this true?? You do sweat a lot but I'm unsure if the heated room would actually have a real difference.

I don't know about hot yoga in particular, but I agree that in general the figures I've seen mentioned online for calories burned during yoga seem very unrealistic. I do Vinyasa and a class called Athletic Yoga (which really kicks my butt) but I don't count it for calories. I just consider it something good I do for myself!

Getting very hot and sweaty during a workout causes substantial immediate weight loss due to dehydration, but does not cause you to burn even 1 additional calorie over expending the same effort in a refrigerated environment. In fact, there is some data to suggest that substantial shivering WILL up the calorie burn a little. So, many good reasons to try yoga (and I'm sure some good reasons to try "hot" yoga), but enhanced calorie burning is not among them. Sorry.

thanks guys....I knew about the dehydration effect but thought maybe it would cause your heart to work more and therefore increase metabolism....but in any case the added flexibility is worth it anyway!

I go to hot yoga every other week and even though I'm in pretty good shape, it destroys me, but then I feel amazing afterwards which is why I keep going. It probably depends what type of yoga you're doing, but at this place, it really is a workout. I get a better workout than if I had gone running and my muscles are usually sore for days. If it weren't $12-15/class, I would go everyday! And you should see the "regulars" that do go every day...they are ridiculously fit.

I don't think the heat makes you burn more calories, but for me, I'm almost distracted by the heat such that I end up pushing myself farther than I would otherwise. I don't know if that makes sense and the heat probably isn't supposed to distract you because you should be all zen-like, but I'm not the type of person that loves being outside on a hot, humid summer day either

I go to bikram yoga occasionally (plan to go today) and wonder the same thing. I've actually heard your body DOES work harder if you exercise in the heat or cold, because it is struggling to cool you off/warm you up. I don't know if it burns THAT many additional calories, but it might give you a few.

Bikram yoga is the same routine everywhere, so not sure if you are referring to that or general yoga in a heated room...but bikram followers insist crazy numbers like 500,800,1000 calories burned in the 90 minute routine. I find those hard to believe, but think maybe 200-300 might be realistic.

I could actually see it being a serious calorie burn, not for the water weight lost through sweat obviously, but due to what one of you said about the heat being distracting and making you push yourself further. When your muscles are warmer than usual, you can push them to limits you can't when they're cold. If you think about it, that's the whole point of a "warm up." Try doing a standing forward bend on cold muscle in a cold room. You aren't as limber as if you do it after a thirty minute jog in a warmer environment. For the calorie burn effect, I think you're probably able to get deeper into strength-building poses, which has an afterburn effect.

I made it to bikram classes the last 2 days and i have to say I feel pretty fantastic!!!

I LOVE yoga, but I've never been able to get into bikram that much. I've gone a few times in the past because there is a big studio near my house that offers a lot of classes, so it's convenient. but really I've always loved the iyengar style and try to do that.

I am so surprised that I can't wait to go back - I think maybe there is something to people who say it's addicting.