Does hot yoga increase cortisol? Briefly, it can, because any hard workout nudges this stress hormone up for a short time. Over weeks, though, the hot yoga cortisol picture flips. In an 8-week trial of heated yoga, women who reacted most strongly to stress showed a smaller cortisol spike under pressure than women who did no yoga.
Does Hot Yoga Increase Cortisol? The Graded Answer
On this site we grade every health claim by the study behind it. So here is the honest version. Asking "does hot yoga increase cortisol" is really asking two questions, and they have different answers.
The first hot yoga cortisol question is what happens during and right after one class. The second is what happens to your stress response after weeks of practice. Here is what the research supports:
- During one class: cortisol may rise a little, as it does with most exercise. Lab studies show the clear rise starts at about 60% of your maximum aerobic effort.
- Right after class: exercise cortisol usually peaks 20 to 30 minutes after you stop, then settles back down.
- After 8 weeks: the main randomised trial of heated yoga and cortisol found a smaller cortisol response to a stress test in the women who reacted most strongly at the start.
That's the core hot yoga cortisol finding. A short, normal rise is part of how your body handles effort. It's not the same thing as chronically high cortisol, which is the problem most people actually worry about.
The Hopkins 2016 Cortisol Study Unpacked
Almost every article on hot yoga cortisol points back to one paper. It's often called "the Hopkins study", but the name comes from its lead author, L.B. Hopkins, not from Johns Hopkins University. You can read the full heated hatha yoga and cortisol trial free on PubMed Central.
It appeared in the Journal of Consulting and Clinical Psychology in 2016. It remains the main hot yoga cortisol trial, so here is what the team did, step by step, in plain language.
Who Took Part
The researchers recruited 52 women aged 25 to 46. Each one reported high everyday stress, and each one tended to eat when upset. None of them practised yoga regularly before the study.
Then a coin-flip style randomisation split them into two groups. Twenty-seven started yoga straight away. The other 25 joined a waitlist and got their yoga membership after the study ended.
What the Yoga Group Did
The yoga group had 8 weeks of the classic hot class: 26 postures, 2 breathing exercises and rest on the floor, in a room heated to 104°F (40°C). Each class lasted 90 minutes, and the instruction was to attend at least twice a week.
Real life got in the way, as it usually does. On average the women attended about 1.6 classes a week, and only 37% reached the twice-weekly target. Keep that in mind, because it means the results came from a fairly light dose.
How They Measured Stress Cortisol
Before and after the 8 weeks, every woman came to the lab for about 30 minutes of deliberate stress. The tasks included a version of the Trier Social Stress Test (a public speaking challenge), a breath-holding task and a frustrating mirror-tracing puzzle.
The team took seven saliva samples per visit. From those, they worked out how much salivary cortisol rose in response to the stress. Scientists call this cortisol reactivity, and it's a better window on your stress system than a single morning reading.
What Happened to Cortisol
Here is the key hot yoga cortisol result. The women who started as high reactors, meaning their cortisol jumped most under stress, saw that jump shrink more in the yoga group than on the waitlist. The effect size was large (d = 0.85), and their reactivity after treatment was also lower.
However, the low reactors showed no significant difference. So hot yoga did not lower everyone's stress cortisol. Instead, it seemed to help the people whose stress response ran hottest to begin with.
What Happened to Stress Eating
The yoga group also reported a bigger drop in binge eating episodes than the waitlist group. They became less likely to eat as a way of coping with feelings, too. For women who joined because stress drove their eating, that matters as much as any hormone number.
The Fine Print
The authors call their results "preliminary support", and they're right to. These limits stop us from overselling it:
- Waitlist control. The comparison group did nothing, so we can't tell whether heat, yoga, or simply joining a class did the work.
- Women only. All 52 volunteers were women with stress-related eating, so the result may not apply to men or to relaxed practitioners.
- Small sample. With about 25 people per group, one trial can't settle the question.
- Low attendance. Most women did fewer classes than planned, so nobody knows yet what a higher dose would do.
Hot Yoga Cortisol Research, Graded
One trial is a start, not an answer. So we placed it next to the other studies we could open and check. Only the first row tested heated yoga and cortisol together. The others fill in how exercise, heat and yoga each affect stress hormones.
| Study | Who and what | Cortisol finding | What it tells you | Our grade |
|---|---|---|---|---|
| Hopkins et al., 2016 | 52 stressed women, 8 weeks of 90-minute classes at 104°F vs waitlist | Smaller stress-test cortisol rise in high reactors; no difference in low reactors | Regular hot yoga may calm an overactive stress response | B (randomised, small, waitlist control) |
| Hill et al., 2008 | 12 active men, exercise sessions at 40%, 60% and 80% of VO2max vs rest | +6% at 40%, +40% at 60%, +83% at 80% | Cortisol rises with effort, mainly above 60% of max | B (controlled lab study, men only) |
| Lambert et al., 2020 | 16 experienced practitioners, one 60-minute hot class vs room temperature | Not measured | Oxygen use stayed near a quarter of their maximum in both rooms | C (single session, no hormone data) |
| Pascoe et al., 2017 | Meta-analysis of 42 studies of yoga and mindfulness programmes | Lower evening and waking cortisol with yoga postures vs active controls | Over weeks, yoga tends to lower everyday cortisol | A- (meta-analysis, mixed programmes, mostly not heated) |
Read across the rows and a hot yoga cortisol pattern appears. Hard effort pushes cortisol up for a while. Yet a regular yoga practice, heated or not, tends to bring everyday cortisol down. Those two facts don't contradict each other, because they describe different time scales.
Hot Yoga and Stress Hormones in 4 Numbers
If you only scan one part of this page, scan these four cards. Together they explain why hot yoga cortisol changes look so different after one class and after one month.
60%
The effort threshold
Cortisol rose about 40% at 60% of max effort, and 83% at 80%.
About 25%
Oxygen use in a hot class
Experienced students worked near a quarter of their aerobic maximum.
20-30 min
When exercise cortisol peaks
The rise tops out after you stop, then falls back.
8 weeks
Calmer stress response
High-reacting women had a smaller cortisol spike after hot yoga.
Why One Hot Class Can Raise Cortisol
Cortisol isn't a villain. It helps your body find energy for effort. So a short hot yoga cortisol rise during a demanding class is your body doing its job. The real questions are how big the rise is, and how fast it settles.
Effort Sets the Size of the Rise
The clearest data comes from a lab study by Hill and colleagues. Twelve active men exercised at three intensities on separate days. Cortisol barely moved at 40% of their maximum, rose about 40% at 60%, and jumped about 83% at 80%. The abstract of the exercise intensity and cortisol study sets out the full figures.
After the authors corrected for fluid loss and time of day, the easy session actually lowered cortisol. That's a useful detail, because it shows intensity, not exercise itself, drives the spike.
Most of a Hot Class Sits Below That Line
Hot yoga feels intense, mainly because of the heat and the sweat. But feeling hot isn't the same as working at a high aerobic level. In a 2020 study, 16 experienced practitioners did a one-hour hot sequence and the same sequence at room temperature.
Their oxygen use stayed close to a quarter of their aerobic maximum in both rooms, and average heart rates sat around 110 to 115 beats per minute. You can check the numbers in the heated yoga energy and inflammation study. That's well under the 60% line where cortisol clearly climbs in the lab data.
One caution, though. Beginners may work harder than experienced students, and that study didn't measure cortisol at all. So treat this as a strong clue, not proof.
Heat Adds Its Own Strain
Heat is a stressor too. In the same 2020 study, the inflammation marker IL-6 rose about 15-fold after the heated session, compared with about 2-fold at room temperature. IL-6 is a signalling molecule linked to inflammation, and the study didn't track how long it stayed raised.
Still, it reminds us that the heat changes how your body responds, and hot yoga stress hormones are part of that response. For example, dehydration, poor sleep or fasting before class could all add load on a hard day. That's when a short cortisol rise is more likely to feel like a drain.
The Rise Is Short
A review in Frontiers in Behavioral Neuroscience notes that exercise needs roughly 10 to 15 minutes to raise cortisol. It also says levels peak 20 to 30 minutes after the session ends. You can read the commentary on cortisol and exercise in young adults for the details. After that peak, levels fall back toward normal.
That's why the honest answer to "does hot yoga increase cortisol" depends on the clock. Measure hot yoga cortisol 20 minutes after a tough class and you may see a bump. Measure your stress response after 8 weeks of practice, and the trial data points the other way.
Does Hot Yoga Lower Cortisol Over Time?
The best wider evidence is a 2017 meta-analysis by Pascoe and colleagues in Psychoneuroendocrinology. It pooled 42 studies of yoga and mindfulness programmes. Compared with active control groups, yoga posture practice lowered both evening cortisol and waking cortisol, as well as resting heart rate.
Most of those programmes were not heated, so direct hot yoga cortisol data is thinner. Even so, the 26-posture hot class shares the same core tools: held postures, slow breathing and floor rest between efforts. As a result, it's reasonable to expect similar long-term effects, while noting that heated classes have far less direct data.
Mental health trials point the same way, so the long-term hot yoga cortisol story fits a wider pattern. A 2022 study by Hui and colleagues found that hot yoga reduced state anxiety.
Meanwhile, an 8-week Massachusetts General Hospital trial (Nyer, 2023) found that 59% of people in heated yoga had their depression symptoms cut by half or more, against 6.3% on the waitlist. We look at that trial closely in our article on what hot yoga mental health researchers measured.
Heart health research supports the calm-down story, too. For example, several trials looked at blood pressure and arteries after weeks of hot classes, which we grade in our review of whether hot yoga is good for your heart.
Is Hot Yoga Bad for High Cortisol? Who Should Be Careful
For most healthy adults, the evidence suggests hot yoga is more likely to help an overworked stress system than to harm it. The Hopkins trial even found the biggest benefit in the women whose cortisol reacted most. But "most people" is not "everyone".
Please consult a healthcare professional before you start if any of these apply to you:
- A diagnosed hormone or adrenal condition, or medication that affects cortisol.
- A heart condition or blood pressure that isn't well controlled.
- Pregnancy, because overheating carries extra risk.
- Severe fatigue, burnout or poor sleep that isn't improving with rest.
- A history of fainting or heat illness.
Also, notice how you feel after class. If you leave buzzing and can't sleep, or you feel wiped out for a day, that's useful feedback. It's a sign to scale back the dose, not to push harder.
How to Keep Hot Yoga Cortisol in Check: 6 Steps
If you worry about hot yoga cortisol spikes, you don't have to quit. Instead, shape the practice so the short spike stays short. These steps follow the research above:
- Start with two classes a week. That's the dose the 8-week trial prescribed, and it still showed results with lower attendance.
- Work at a conversational effort. Stay well below the 60% effort line, especially in your first month.
- Arrive hydrated and fed. Drink water through the day and eat a light meal a few hours before class.
- Take every floor rest. The rests between postures let your heart rate and breathing settle.
- Breathe through your nose. Slow nasal breathing keeps the class calm rather than frantic.
- Give late classes a buffer. Since exercise cortisol peaks 20 to 30 minutes after you stop, leave time to cool down before bed.
The final floor rest, Savasana, deserves special attention. Many students rush out of it. Yet it's the moment your nervous system shifts from effort back to recovery, so stay for the full minute or two.
Hot Yoga Cortisol and Weight Gain Worries
Some people ask whether a hot yoga cortisol rise could cause belly fat. No study has shown that. In fact, the Hopkins trial found less stress eating after 8 weeks, not more. We cover what the scale really does in our review of hot yoga weight loss studies.
What Our Trainees Say About Stress in the Heat
Hot yoga cortisol data tells one part of the story. Our trainees tell another: what it feels like to meet fear and pressure in a hot room and come out steadier. These comments come from Google and video reviews of YogaFX teacher trainings.
"I've never traveled on my own. I'm a very fearful, shy person... I feel like I've just blossomed into the person I really want to be."
Donna, YouTube review, 2026
"The personal interaction to all his student as individuals is exemplary and respectful, reassuring and brings out the confidence in the most reluctant and doubtful student."
Konrad, Google review, 2025
"Now I believe I can do four classes a day... I know I'm going to teach one day."
Paula, YouTube review, 2025
None of these trainees measured their cortisol, of course. But Donna's words echo the trial's main finding. The people who start out most anxious often have the most to gain from learning to stay calm in the heat. You can watch her full review below.
Teach the Stress Science With YogaFX
Students will ask you, "does hot yoga increase cortisol?" A good teacher answers with the study, the dose and the fine print, not with a slogan. That is exactly what our hot yoga teacher training online course prepares you to do, with the 26 postures, the dialogue and the physiology taught at home.
The course is led by Mr. Ian Terry, E-RYT 500, who has more than 12,000 teaching hours. He trained for 5 years, from 2014 to 2019, with the founder of the method. Since 2017, YogaFX has trained more than 1,500 graduates from 80+ countries.
Mr. Ian teaches trainees to cue the heat as a tool, not a test. So you learn to spot the student who is pushing past a calm effort, and to guide them back to their breath before stress takes over.
- See how online study works. Read the 8-week breakdown of online yoga teacher training.
- Learn the physiology. Know why heart rate, sweat and cortisol each tell you something different about a student's effort.
- Teach in the Original Hot 26&2 Yoga method, the same 26-posture sequence the 2016 hot yoga cortisol trial tested.
When you're ready for the heat in person, the next step is the 6-day Bikram Hot 26&2 Yoga Teacher Training MasterClass in Bali. The next batch checks in on Sunday 24 January 2027 at Soham Wellness Center in Seminyak. The Early Bird price is US$1,899 (normally US$1,999), with payment plans from US$250 a month.
FAQ
Does hot yoga increase cortisol levels?
For a short time, it can. Cortisol rises with effort, mostly above 60% of your maximum, and peaks 20 to 30 minutes after exercise. Over 8 weeks, though, a randomised trial found that heated yoga shrank the stress-test cortisol response in women who reacted most strongly at the start.
Does hot yoga lower cortisol?
It may, with regular practice. A 2016 trial of 8 weeks of 90-minute hot classes found a smaller cortisol spike under stress in high-reacting women. A 2017 meta-analysis of 42 studies also linked yoga postures with lower waking and evening cortisol, although most of those classes were not heated.
Is hot yoga good for high cortisol?
Research suggests it may help people with a strong stress response. In the 2016 trial, the women whose cortisol jumped most under pressure benefited most. Start with two classes a week at a calm effort, and consult a healthcare professional first if you have a diagnosed hormone condition.
Is hot yoga bad for cortisol?
Not for most healthy adults. A brief rise during a hard class is a normal response to effort, and the research shows it is temporary rather than lasting. Problems are more likely if you train very hard every day, sleep badly or skip water and food, so match your dose to your recovery.
Does yoga increase cortisol?
Gentle yoga rarely does, because cortisol mainly rises above about 60% of maximum effort. A meta-analysis of 42 studies found yoga postures lowered waking and evening cortisol compared with active controls. Fast, demanding styles can cause a short rise, much like any other moderate to hard workout.
Still have questions? Mr. Ian and the YogaFX team answer them personally. Take the 2-minute quiz to see if you're ready to teach hot yoga, or go straight to the online course enrolment page.