Hot yoga vs regular yoga comes down to one measured difference. In a 2018 crossover trial, 14 people used the same oxygen in a 35.3°C room and a 22.1°C room, but their hearts beat faster in the heat. So the heat adds strain, not extra work.
That sounds small, yet it changes how you choose a class and how you explain it if you teach.
This guide compares three trials that put the same yoga into a hot room and a cooler room: Boyd 2018, Bourbeau 2021 and Lambert 2020. Each one is small, so we report what it measured and what it can't tell you. If you searched for hot yoga vs normal yoga, this is the evidence in one place.
Mr. Ian Terry, E-RYT 500, trained for five years, from 2014 to 2019, with the founder of the Bikram Hot 26&2 method. He has taught for 12,000+ hours and has trained 1,500+ graduates from 80+ countries since he founded YogaFX in 2017. His rule is simple: quote the study exactly.
Hot Yoga vs Regular Yoga in Three Trials: The Short Answer
Three trials give the cleanest view of hot yoga vs regular yoga, because each one kept the yoga the same and changed only the room. Here they are side by side. We go through each one below.
| Trial | Who and how long | Rooms compared | What the heat changed | What stayed the same |
|---|---|---|---|---|
| Boyd et al., 2018 | 14 people, two identical sessions of about 20 minutes | 35.3°C vs 22.1°C | Heart rate 67.0% vs 60.8% of maximum; effort rating 12 vs 11 | Oxygen use, 30.9% vs 30.5% of maximum |
| Bourbeau et al., 2021 | 22 healthy adults, 12 sessions over 4 weeks | About 40°C vs 18 to 22°C | Aerobic fitness rose in the hot group only; a heat-stress protein (HSP70) looked higher | No heat acclimation; no change in perceived stress; BDNF rose in both groups |
| Lambert et al., 2020 | 16 experienced practitioners, one hour on two days | 105°F vs 74°F | Hip abduction gain 6.6° vs 2.3°; lower respiratory exchange ratio (0.89 vs 0.95) | Energy cost, 151 vs 156 kcal; no significant difference |
How to read the table
Read the last two columns first. Heat changed how hard the body worked to stay cool, such as heart rate and effort rating. It did not change the oxygen cost of the poses themselves.
That is the pattern in all three trials, and it is the heart of hot yoga vs regular yoga. The difference between hot yoga and normal yoga is the load on your cooling system, not the work of the poses.
The numbers at a glance
Hot yoga vs regular yoga by the numbers
Boyd 2018: Same Yoga, Same Oxygen, Faster Heart
Boyd and colleagues ran a randomised crossover trial and published it in Applied Physiology, Nutrition, and Metabolism in 2018. Fourteen people did two identical yoga sessions of about 20 minutes. One session took place in a hot room and one in a thermo-neutral room, so each person acted as their own comparison.
For a single class, it is the cleanest test of hot yoga vs regular yoga we found.
What the trial measured
- The rooms. Hot was 35.3°C with 20.5% humidity. Thermo-neutral was 22.1°C with 27.8% humidity.
- Oxygen use. 30.9% vs 30.5% of maximum, with no difference between rooms (p = 0.68).
- Heart rate. 67.0% vs 60.8% of maximum, higher in the heat (p = 0.01).
- Effort rating. 12 vs 11, higher in the heat (p = 0.04).
What it means
Here is the key point. Oxygen use matched, so the muscles did the same job in both rooms. Heart rate and effort did not match, so the body paid an extra price to cool itself. That is why a hot class can feel harder even when the poses cost the same energy.
The authors also sorted the sessions by intensity. By oxygen use, both rooms counted as light exercise. By heart rate and effort rating, the hot room reached moderate. As a result, the label you give a hot class depends on which gauge you read.
Two limits matter. The sessions lasted only about 20 minutes, and the hot room was 35.3°C, which is cooler than a 40°C studio. A full 90-minute class may behave differently. For heart rate zones posture by posture, see our guide that asks is hot yoga a cardio workout.
Bourbeau 2021: What Twelve Hot Sessions Changed
Bourbeau and colleagues asked a different question: what happens over weeks, not minutes? In the International Journal of Yoga (2021), they randomly split 22 healthy adults into two groups of 11. The average age was 26, and nobody had practised yoga before. Each person did 12 sessions over four weeks, three a week, of a modified Bikram sequence.
One group practised in a hot room at about 40°C with 40% humidity. The other practised at 18 to 22°C. You can read the full open-access paper yourself. For hot yoga vs regular yoga over weeks, it is the best test we have.
- Fitness. Maximal aerobic fitness rose from 3.22 to 3.46 L/min in the hot group only.
- Cell stress protein. HSP70, a protein that helps cells cope with heat, looked higher in the hot group only.
- Heat acclimation. None showed up after twelve hot sessions.
- Stress. Perceived stress and the stress hormone ACTH did not change significantly in either group.
- BDNF. This brain-related protein rose with yoga in both groups, so it did not depend on temperature.
So heat may add a small fitness edge, but there is a catch. Each group held only 11 people. The authors concluded that twelve hot sessions promoted cardiovascular fitness and cell-level heat tolerance. A group that small can show a signal, but it cannot settle the question.
The BDNF result points the other way. Both rooms raised it, which suggests the practice itself carries much of the benefit. That echoes Boyd 2018: the poses do the main work, and the heat adds its own load on top.
Lambert 2020: One Hour, Two Rooms
A third trial, by Lambert and colleagues in the International Journal of Exercise Science (2020), tested 16 experienced practitioners on two separate days. They did the same one-hour Bikram sequence at 105°F and at 74°F, both at 40% humidity. Read the full paper on PubMed Central for every detail.
Energy cost was almost identical, 151 and 156 kcal. Hip abduction improved more in the heat, by 6.6° against 2.3°. The respiratory exchange ratio was lower in the hot room (0.89 against 0.95), which points to a little more fat used as fuel.
Blood levels of IL-6, a signalling protein, rose only after the hot class. The authors concluded that heat does not significantly raise the aerobic energy cost of yoga. So is hot yoga better than normal yoga for calories? In this trial, no.
If you want the calorie and flexibility side of this comparison in more detail, our sister site covers what the heat adds according to lab studies.
Why Heart Rate and Oxygen Use Tell Different Stories
Three gauges appear in these trials, and each one measures something different. Mixing them up is the most common mistake in the hot yoga vs regular yoga debate, and it's why two people can read the same trial and disagree.
- Oxygen use reflects the work your muscles do. It matched between rooms in Boyd 2018.
- Heart rate reflects the total load on your circulation, including the effort of moving blood to the skin to cool you. It ran higher in the heat.
- Effort rating reflects how hard the session feels. It also ran higher in the heat.
The usual explanation is simple. In a hot room, your body sends more blood to the skin so sweat can cool you. As a result, your heart works harder for the same poses. That means a heart rate watch will read higher in a hot class, so compare like with like when you track your own progress.
This also explains why results take time to read. Our timeline of how long hot yoga takes to show results sets out what longer trials found at 8 weeks.
Hot Yoga vs Regular Yoga for Teachers: What to Tell Students
Students ask about hot yoga vs regular yoga in the first week, so a teacher needs a clear, honest answer. YogaFX online hot yoga teacher training is led by the science and graded evidence, so trainees practise exactly this skill: explain what a study found, then say what it cannot show.
- Say what the heat does. "Heat changes how hard your body works to cool down, not how much work the poses are."
- Say what it may add. "A small trial found a fitness gain in a hot room over four weeks, but it was only 22 people."
- Say what the room does not own. "Both rooms raised a brain-related protein, so the practice itself matters."
- Say how to choose. "Pick the room you can attend three times a week."
- Say who should check first. "If you have a heart or blood pressure condition, or you are pregnant, ask a healthcare professional before a heated class."
Our honest 8-week breakdown of online yoga teacher training shows how a trainee learns the dialogue and the research side by side.
What These Trials Cannot Tell You
Good science writing says what it cannot show. Across the three trials, the same limits keep appearing.
- Small samples. The trials had 14, 22 and 16 people.
- Short follow-up. They ran from about 20 minutes to four weeks. None followed anyone for years.
- Healthy adults. Participants were mostly young or experienced practitioners, so the results may not fit people with medical conditions.
- Different rooms. The hot rooms ranged from 35.3°C to about 40°C, so "hot" does not mean one fixed temperature in any hot yoga vs regular yoga comparison.
That is why we say hot yoga may help and never that it treats a condition. If you are thinking about weight, our guide asks is hot yoga good for weight loss. For the wider timeline of studies, see Bikram yoga history in five studies.
This article is for information only and is not medical advice. Consult a healthcare professional before starting any heated exercise, especially if you have a heart condition, high blood pressure or you are pregnant.
How to Run Your Own Hot Yoga vs Regular Yoga Test
The best answer to hot yoga vs regular yoga is the one you can measure in your own week, and you'll learn more from three weeks of notes than from a debate. Run a fair test over about three weeks, so that heat is the only thing that changes.
- Match the classes. Choose one hot class and one regular class of the same length and level.
- Repeat each three times. The first class in any room is always the hardest.
- Rate effort. Give each class a score from 1 to 10 as soon as it ends.
- Check the next morning. Note stiffness, sleep and energy.
- Mind the watch. If you wear a heart rate monitor, expect higher readings in the hot room for the same poses.
- Keep the one you attend. The class you actually go to beats the better class you skip.
Drink water through the day, not only before class. If you feel faint, nauseated or confused, stop and rest in a cooler spot. A good teacher will tell you the same.
What the Room Does Not Change: The Teaching
Whatever the temperature, a class is still a teacher guiding a group, and that holds for both sides of hot yoga vs regular yoga. In the Bikram Hot 26&2 method, the guide is a scripted dialogue with no demonstration and no music. A trainee learns it word by word, and the room conditions stay fixed so that one class can be compared with the next.
That fixed setting is one reason researchers pick this method. It gives them the same poses, the same timing and the same words in every room, so the only thing they change is the temperature.
What YogaFX Students Say
Reviews are not research, and these ones are about the teacher training rather than the heat question. They show what the teaching floor feels like from the student side, in the students' own words.
Such an amazing and mind blowing experience. Very very recommended, everything is so smooth and very well organised and very professional.
Lilywati, Google review, 2025
What an awesome experience. Ian knows how to take you to your limits and beyond.
Chris, YouTube review, 2024
I really enjoyed meeting you and all of you are like family to me.
Stacey, YouTube review, 2024
Learn Hot Yoga Teaching Online, With the Evidence Built In
If this look at hot yoga vs regular yoga made you curious about teaching the method, the next step is to learn it properly. YogaFX online hot yoga teacher training is led by the science and graded evidence, so you learn the sequence and the research on the same page.
- You learn the dialogue the way it is delivered in a real class.
- You learn to read a study with its limits attached to every claim.
- You get a clear next step from Mr. Ian and the team.
Because heat research is still young, new teachers who can read a trial critically stand out.
FAQ
Is hot yoga or regular yoga better for beginners?
For hot yoga vs regular yoga, beginners usually do better with regular yoga, because they are still learning balance and breathing. In the 2018 trial, heart rate and effort were higher in the heat for the same poses. Some beginners do well in a hot room, so start with two classes a week and rest freely.
Does hot yoga build fitness faster than regular yoga?
One four-week trial of 22 healthy adults found aerobic fitness rose in the hot group only, from 3.22 to 3.46 L/min. The groups were only 11 people each, so the result is early. Both rooms raised a brain-related protein, BDNF, so regular yoga still helps.
What is the difference between warm yoga and hot yoga?
There is no single standard for hot yoga vs regular yoga rooms. The trials above used rooms from 35.3°C to about 40°C for "hot" and 18 to 23°C for regular. Studios label rooms differently, so ask for the actual temperature and humidity before you book, and build up slowly if the room is hot.
Is hot yoga less safe than regular yoga?
Heat adds strain. In the 2018 trial, heart rate and perceived effort were higher in the hot room, even though oxygen use matched. That means a hot class asks more of your cooling system. Drink water, rest when you need to, and check with a healthcare professional if you have a heart or blood pressure condition.
Is YogaFX official Bikram Choudhury teacher training?
No. YogaFX is independent training, not official Bikram Choudhury Teacher Training. Mr. Ian Terry, E-RYT 500, trained for five years, from 2014 to 2019, with the founder of the Bikram Hot 26&2 method, and now teaches it with 12,000+ teaching hours behind him.
Still have questions? Message Mr. Ian and the YogaFX team on WhatsApp and we will answer them personally.
Founder and lead trainer of YogaFX International Yoga Teaching Academy, with more than 12,000 hours of teaching. He trained for 5 years, from 2014 to 2019, with the founder of the Bikram Hot 26&2 method.
You may also like
Explore all articles ↗
Teacher Training Guides11 min read14 Nov 2026International Yoga Sports Federation and Yoga as a Sport: What Recognition Requires
Read article ↗
Teacher Training Guides11 min read13 Nov 2026Sauna After Hot Yoga? What Core Temperature Data Suggests
Read article ↗
Teacher Training Guides10 min read13 Nov 2026