Hot Yoga and Bikram Yoga: What They Are and What Is Known
What hot yoga and Bikram yoga are, what trials found for mood, stress and fitness, why calorie and detox claims are unproven, and heat, dehydration, pregnancy and age cautions.
Content last updated . This page has not been medically reviewed.
Heat comes first: who should be careful
NCCIH says hot yoga has special risks related to overheating and dehydration, and that you should avoid hot yoga while pregnant because it can cause overheating. [1] NCCIH also notes that older adults and people with health conditions should talk with their health care providers and the instructor first. [1] The NHS lists dizziness, headache, nausea, heavy sweating with pale clammy skin and cramps as signs of heat exhaustion, and says heatstroke, with hot skin without sweating and confusion, is a medical emergency needing immediate medical help. [2] The NHS says someone with signs of heat exhaustion needs to be cooled down and given fluids. [2] In the US, call 911. See yoga safety, heat and dehydration for more.What these terms mean
"Hot yoga" is a loose label. One 2025 systematic review defined it as any form of yoga done in warm to hot conditions, 25 degrees C or above. [3] Bikram yoga is the best-known version: a standardized series of poses performed to an instructional script in a heated environment of 40.6 degrees C and 40% humidity. [4] A class is a fixed sequence of 24 asanas and two breathing exercises, per an encyclopedia account. [5] The last breathing exercise is kapalabhati, a forceful practice; see pranayama for why forceful breathing needs care. [5]Of the 43 hot yoga studies in the 2025 review, 74% used Bikram, so most of what is known about hot yoga is actually about Bikram. [3] The rest were generalised hot yoga (19%), hatha (5%) and vinyasa (2%). [3]
Origins and controversies
Bikram yoga was spread by Bikram Choudhury, who was born in Calcutta in 1944, and is based on the teachings of B. C. Ghosh. It became popular in the early 1970s. [5] The company peaked at about 1,650 studios in at least 40 countries in 2006. [5] Because it became popular in the 1970s, it is a modern studio format. See the history of yoga.Choudhury tried to copyright the sequence from 2011 and was ultimately unsuccessful. In 2016, the same account says, he was facing lawsuits and accusations of sexual assault. [5] We have not read court records, so we report these only as allegations and legal events described by an encyclopedia article.
What research shows
Studies of hot yoga are mostly small, short and self-reported, and many lack long follow-up. The 2025 review says some literature lacks rigorous experimental designs. [3]| Question | What the source found | Label |
|---|---|---|
| Does heat make yoga more beneficial? | A 12-week trial of 52 adults compared Bikram yoga at 40.5 C, the same series at 23 C, and no yoga; blood-vessel function changes did not differ significantly between groups [6] | no good evidence of added benefit from heat |
| Is it more strenuous or does it burn more calories? | Energy use averaged 286 kcal in a 90-minute class (range 179 to 478), light to moderate intensity [7]; the 2025 review found body temperature and heart rate rose but energy demand was not higher than non-heated yoga [3] | calorie claims not supported |
| Depression | 53 women with depression: response in 61.1% for Bikram yoga, 60.0% for aerobic exercise, 6.7% for waitlist; the study was small, women only, and aerobic exercise was not standardized [8] | promising but limited |
| Stress | 63 sedentary, stressed adults, 16 weeks, no-treatment control; self-reported stress and quality of life improved [9] | promising but limited |
| Greater benefit than other yoga or exercise | Claims are "at present unsubstantiated" [3] | no good evidence |
The 2015 critical review reported that Bikram yoga has been shown to improve strength, range of motion and balance in healthy adults, and called for larger, better-designed trials. [4] Researchers measuring energy use noted that widely repeated claims of up to 1,000 calories per session were unfounded. [7]
Hot yoga is also marketed for "detox" through sweat. We did not find a study that tested that claim in the sources we read: Proper evidence not found. The sources we read focus on hydration and overheating, not on clearing toxins. See yoga myths and misconceptions.
Choosing a class
Ask the studio how the room temperature is set, whether you can leave or rest at any time, whether the teacher will adapt poses, and what their training is. Yoga teaching is generally unregulated. One account says Bikram yoga trains its own teachers. [5] We do not list or rate studios. A heated class is optional: the heart-study authors concluded the poses alone improved vessel function without heat. [6] See how to choose a yoga style and heat exposure research.Frequently asked questions
Is hot yoga better than regular yoga?
Not as shown so far. The 2025 review calls claims of greater benefit unsubstantiated. [3] In one trial the benefit for blood-vessel function did not differ significantly with or without heat. [6]
How many calories does hot yoga burn?
In a lab study of a 90-minute Bikram class the average was 286 kcal, lighter than the 1,000-calorie figure often repeated. [7]
Is hot yoga safe during pregnancy?
NCCIH says to avoid it because it can cause overheating. [1] Check with your provider.
Does hot yoga help depression or stress?
Small trials found improvements versus waitlist or no treatment, but they were small and self-reported. [8][9]
Does sweating in a hot room detox the body?
Proper evidence not found. We read no study testing a detox benefit; the hot yoga sources we read focus on overheating and hydration. [3][10]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety and cautions
- Overheating and dehydration. The 2025 review warns that case studies report ill health following hot yoga. [3] In a survey of 700 people, instructor encouragement was linked to more protective hydration behaviors, and the authors say much remains to be understood about hot yoga safety. [10]
- Injury. A 2013 review of 76 yoga-related adverse events included 3 in Bikram yoga. [5] A 2026 review found Bikram, Ashtanga and hatha yoga the styles most often named in adverse events, but case reports cannot show how common events are. [11]
- Pregnancy. NCCIH advises avoiding hot yoga. [1] We found only a survey of studio managers on hot yoga in pregnancy, noting that limited literature exists. [12] See yoga in pregnancy.
- Older adults and heat tolerance. The Bikram heart-study authors point to an increased tendency toward heat intolerance in aging adults. [6]
- Other conditions. NCCIH lists knee or hip injuries, lumbar spine disease, severe high blood pressure, balance issues and glaucoma as conditions that may call for modifications. [1] Which medicines or heart conditions make heat risky: Proper evidence not found in the sources we read; ask your clinician.