My first experience of hot yoga was fairly traumatic. The smell in the then Bikram Kentish Town studio. The aggressive teaching. The gross, gross sweaty carpet. The speedos. And, the sweat. Oh the sweat like you’ve never sweated before, even having grown up in Greece and being used to fairly really hot temperatures in the summer. As I sat on the tube in my sweat-drenched clothes, I vowed – never again!
Fast forward a few years later (maybe 2013?). A new yoga studio opens down the road from my house – a hot yoga studio. You can imagine my disappointment. They promised a nicer experience to the grossness of the Bikram studios. I said to myself, just try again. And so I did. And I really wanted to like it. I tried very hard to like it. For years I dipped in and out of it thinking that maybe next time it will be better.
Then, just before and during my yoga teacher training, I practiced hot yoga multiple times a week. It kind of grew on me I suppose, although I was the one who looked for the coolest spot in the room. I endured washing my hair multiple times and week (and if you are a fellow curly, you know how painful this is). I did endless laundry, and somehow the smell of hot yoga sweat (a special kind of sweat apparently) never went away. I did all of that, somehow thinking that maybe, just maybe, I like hot yoga. And as soon as my teacher training ended, I never set foot in that studio again.
Why am I telling you this? Because my inner masochist decided that maybe I should try again. I have since moved, but my closest studio is, sigh, another hot yoga studio. I dwelled on it for weeks. I booked my intro class and kept wanting to cancel it. The hot yoga dread is real.
And yet, I know other people love it. After my first class, I chatted with the teacher, who told me she doesn’t like room temperature classes. So I wondered – is there any scientific evidence that hot yoga may be more beneficial than room temperature yoga? Could I use science as my extrinsic motivation to stick with the studio?
The short answer is: No
I found six studies (1, 2, 3, 4, 5, 6) that directly compared hot yoga to normal temperature yoga. The suffer from some of the usual caveats – they are really quite small. But there is one benefit in the design here: we know exactly what the intervention was in each case because Bikram yoga is basically the same no matter where you practice (even what the teachers say), and most hot yoga classes have more or less kept the same structure for their set sequences, ie a hatha-style class with set components (standing, seated, reclining etc).
Here’s a little more detail.
1. Effects on cardiovascular system
There was no difference in arterial stiffness – a marker of increased risk of cardiovascular disease, including hypertension and stroke – between participants who practiced Bikram yoga or yoga at room temperature for 12 weeks.
There was also no difference in endothelial vasodilation – that’s the ability of the cells that line blood vessels (endothelial cells) to expand blood vessels and support strong blood flow – between participants who practiced Bikram yoga or yoga at room temperature for 12 weeks.
So it’s unlikely that hot yoga is better for your heart health than room temperature yoga.
2. Effects on cardiorespiratory fitness
Some inconsistencies here but worth pointing out that all these studies were ridiculously small (14, 16 and 22 participants), so I wouldn’t put much weight on their findings. I probably shouldn’t even mention them but then this blog post would be very very short.
Three studies looked at oxygen consumption; two found no difference in the amount of oxygen used during the class between participants who practiced Bikram/hot yoga and room temperature yoga (1 hour session or 20 minute session). This indicates that the two types of yoga are of equal intensity. The third study found an increase in maximal oxygen consumption following the Bikram yoga session, which they didn’t observe with the room temperature yoga – this wasn’t a single measurement after one class as these participants had already practiced 12 times as part of this study. There may be some truth to this as there is the added stress from heat, but with such small samples and inconsistent findings, I’m just not sold .
There were also inconsistencies on heart rate differences, with just one of the studies finding an increase in heart rate.
All in all, it’s unlikely that the claims that hot yoga is better for your cardiovascular fitness are true. Go for a run instead. Us yogis can be very unfit.
Effects on kidneys
There are, apparently, some concerns over the effects of exercising in a hot environment on the kidneys, but this study found no differences in kidney function between hot and non-hot yoga after 1 year of practice. Good to know.
Effects on mental wellbeing
Both hot yoga and room temperature yoga led to improvements in perceived stress. No surprises.
I’m going to park the claims of crazy weight loss and detoxification to one side because, well, no evidence. The health benefits of Bikram yoga seems to be more or less the same as the health benefits of other yoga styles.
Putting the usual caveats of not-so-great-study-designs to one side, it seems to me that there isn’t much in it between hot and non-hot yoga. Instead, it’s more about offering options. Like everything in life, one size doesn’t fit all, and personalisation/tailoring is the key to success.
Some people love hot yoga – the way the teacher I was chatting with described it, it was hot yoga that made her fall in love with yoga. Other people hate it, but they have tons of options of room temperature yoga they can try out. There’s something out there for everything.
As for me, well, I don’t know. I’m still in the exploring phase. For the third time.
Love it or hate it? What do you think of hot yoga?