Bikram and hot yoga

Bikram yoga is a fixed sequence of 26 postures and two breathing exercises, taught in the same order for 90 minutes in a room heated to about 40 degrees with around 40 per cent humidity. Hot yoga is the umbrella term for any yoga practised in a warm to hot room, which in the research literature means roughly 25 degrees or above, and it usually has no fixed sequence at all.

The two are constantly treated as one thing and they are not. Bikram is a specific method with a specific series and a specific temperature. Hot yoga is a room. Most studios today advertise hot yoga rather than Bikram, often teaching a heated flow class that is closer to vinyasa or power yoga with the thermostat turned up. If the sequence is the same every week and the class is 90 minutes, it is the Bikram series. If it changes and runs an hour, it is hot yoga.

This page is about the heat, because that is the only genuinely interesting question here. Everything else about a hot class is a strong posture practice, and the arguments about pace and fixed sequences are made better on the ashtanga and vinyasa pages.

This is the one question worth answering carefully, and the answer is unusually clean, because somebody ran the obvious experiment.

The controlled comparison. The Bikram yoga heart study randomised 52 sedentary but healthy adults aged 40 to 60 into three groups: the Bikram series at 40.5 degrees, the identical series at 23 degrees, and a sedentary control. The outcome was endothelium dependent vasodilatation, measured as brachial artery flow mediated dilatation, which is a good marker of vascular health. It increased in the unheated group and tended to increase in the heated group, and there were no significant differences between the groups in the change. The authors' own reading was that the postures produced the vascular improvement and the heated environment was not necessary for it. Body fat percentage was lower in the hot group afterwards, which is the one finding that went the other way.

The longer trial. A separate randomised controlled trial put 63 stressed and sedentary adults through a 16 week Bikram programme at 40 degrees. It found no significant improvement in its primary outcome, the high frequency component of heart rate variability, and no between group improvement in blood pressure, cholesterol, glucose or body composition. Attendance was poor, at 27 classes out of 80 recommended, which is a real limitation and is also a finding in itself about how sustainable the format is.

The whole literature. A 2025 systematic review pulled together 43 studies and 942 participants and concluded that hot yoga shows interesting health and functional benefits, and that claims it provides greater benefit than other forms of yoga or than traditional exercise are at present unsubstantiated. A six week randomised trial of hot yoga at 40 degrees in 290 adults did find real improvements in life satisfaction, general health, mindfulness and peace of mind, and its authors stated plainly that they could not separate the heat from the exercise, because there was no unheated comparison group.

So the honest summary is this. Hot yoga is good for you in roughly the way that yoga is good for you. There is no good evidence that the heat adds anything beyond the sensation of having worked very hard, and one well designed comparison suggesting it adds nothing to the vascular benefit at all. The word detoxifying, which you will see on every studio wall, describes no process that anyone can measure. Sweat is thermoregulation.

None of what follows is a reason not to go. It is a reason to go informed, and a good studio will say most of it to you at the door.

• Heat illness. Ninety minutes at 40 degrees is a genuine thermal load. Dizziness, nausea, headache, a stopped sweat or confusion means leave the room, and leaving the room is always allowed. Nobody's first class should be a test of endurance.
• Fluid and salt. You will lose a great deal of both. Drink before, during and after, and if you are sweating that heavily regularly, salt matters as well as water.
• Overstretching. This is the risk nobody mentions and the one I would worry about most. Heat makes a range of movement available that your joints and your control have not earned, and a posture that felt fine at 40 degrees can leave you sore in a way that a room temperature class would not. Go to the depth you can hold cold.
• Who should not be in the room at all. Pregnancy, heart disease, uncontrolled blood pressure, a history of fainting or heat intolerance, and any medication that affects sweating or fluid balance. On pregnancy the advice is not ambiguous: overheating is to be avoided, and prenatal yoga sets out the sourced version of why. Ask a doctor, not a studio.

If you have high blood pressure, read yoga for high blood pressure before booking; if you are managing diabetes, yoga for diabetes covers why a heavily sweated 90 minutes needs planning around food and medication.

The deciding factor here is not fitness or experience. It is whether you like being hot.

• You genuinely enjoy heat and it makes you turn up. Go. Enjoying it is the single best predictor of still practising in two years, and that outweighs every argument on this page.
• You want the vascular and metabolic benefits. You can have them at room temperature. The trial that tested exactly this found the unheated group improved too.
• You are hoping to detoxify or to burn many more calories. Reconsider. Neither claim survives contact with the evidence, and the extra weight you lose in a class is water.
• You are new to yoga. Not here first. A 90 minute heated class is a hard place to learn what a posture should feel like, and heat will let you go further than you should. Four to six weeks of a slower held class first.
• You are pregnant, have a heart condition, uncontrolled blood pressure, or a history of fainting in heat. No, and this is the one flat no on the page.
• You are stiff and want the heat to help. It will feel like it helps. What actually changes a stiff hip over months is long holds, which is yin, and it does not require a hot room.

My verdict. I have no objection to a warm room and a strong practice, and I have a firm objection to what is claimed for it. My reading of the evidence is that the heat is a preference rather than a mechanism: the postures do the work, and one properly designed trial says so directly. If you like it, that is a perfectly good reason, and I would rather somebody spent ninety minutes doing yoga in a room they enjoy than doing nothing in one they do not. What I would ask is this. Do not use the heat to reach a depth you cannot reach cold, because the heat will not be there the day your knee decides to have an opinion about it. And if a studio tells you that you are sweating out toxins, keep going to the class and stop believing that particular sentence.

There is no heated room here, and no style is taught by name at all. What exists is one teacher, about forty years of teaching, one hall at the residents' association in MSR Nagar in north Bangalore, and an hour of asana, pranayama and relaxation taught slowly, in person there or live online, all ages and all levels.

North Bangalore supplies its own heat for a good part of the year, and that is worth mentioning practically rather than as a joke. A hall in April is warm without anybody arranging it, and the sensible response to that is the same as in a hot studio: drink water, come out of a posture when you feel light headed, and do not take a deeper shape simply because the heat makes it available. Those instructions are given out loud in the class rather than assumed.

If a strong sweat is what you are after, that is a limitation of a slow hour and it should be said plainly rather than argued around. What a slow class gives you instead is the postures accurately enough to make a strong class safe. Surya Namaskar is the part of the tradition that raises your temperature honestly, how to start yoga at home gives you a first week, and the first class is free if you want to see the room. Timings and costs are on the classes page, and there is a live online option if a hall in April does not appeal.

The Bikram series is 26 postures and two breathing exercises, and it is more standing work and more backbending than most people expect. Knowing the family of shapes is enough to decide.

The class opens with a standing breathing exercise and a strong side bend from Tadasana, then a long standing block containing a forward fold much like Uttanasana, standing balances of the kind this site teaches as Vrikshasana, and Trikonasana. The floor block is dominated by backbends, with Bhujangasana and its stronger relatives, the kneeling seat Vajrasana, a seated forward fold close to Paschimottanasana, and a twist. There is a short rest in Savasana between the floor postures and a final breathing exercise resembling Bhastrika.

What the series does not contain is a long relaxation or any real breath training, which is the gap I would fill elsewhere. Anulom Vilom at home and the bedtime sequence on a rest evening are the sensible pairing, and what to wear to a yoga class matters more here than anywhere: you will be wet within fifteen minutes, and a mat with grip stops being optional, which choosing a yoga mat covers.