Hot yoga is any style of yoga performed in a room heated to roughly 90 to 105°F, often with added humidity. The heat is the defining feature: it raises your heart rate, increases sweating, and makes muscles feel looser during practice. What started as a niche discipline tied to one specific style (Bikram) has expanded into a broad category that includes vinyasa flows, power yoga, and other sequences, all done in a heated studio.
How Hot the Room Actually Gets
Studio temperatures vary more than most people expect. Traditional Bikram classes are held at a strict 105°F with 40% humidity. Other hot yoga studios set their own conditions. Modo Yoga, for example, keeps rooms around 99 to 100°F with 40 to 60% humidity. Some studios dip as low as 80°F, while others push past 105°F. The style of yoga, the length of class, and the studio’s philosophy all shape the environment you walk into, so it’s worth checking with a studio before your first visit.
Bikram vs. Other Hot Yoga Styles
Bikram yoga is the most rigid form. It follows a fixed sequence of 26 postures and two breathing exercises, always in the same order, always at 105°F and 40% humidity. There’s no music. The instructor follows a prescribed dialogue rather than improvising. Only licensed Bikram studios can use the trademarked name, and many offer nothing else on their schedule.
General hot yoga is far more flexible. It can be a vinyasa flow, a hatha class, or a power sequence, just in a heated room. Instructors choose their own music, themes, and pose order. The temperature typically lands between 80 and 100°F. If Bikram is a strict recipe, hot yoga is more like “cooking with heat,” where the instructor decides the rest.
What Happens in Your Body During Class
The heat does several things at once. Your heart rate climbs higher than it would in an unheated class, which is why hot yoga can feel more like a cardio workout even though the poses themselves may be gentle. A warmer muscle produces force more efficiently for a given amount of nerve signal, which is part of why deep stretches feel more accessible in the heat.
You also sweat significantly. In a 90-minute Bikram session at 105°F, participants in one study lost an average of 1.54 liters of sweat, roughly 2% of total body weight. That’s about three standard water bottles’ worth. This fluid loss is temporary weight, not fat, but it does mean you need to hydrate deliberately before, during, and after class.
Core body temperature rises measurably. Experienced practitioners see their oral temperature climb by about 1°C (1.8°F) during a session, while beginners tend to see a smaller increase of around 0.6°C. Experienced yogis also sweat more and hit higher heart rates, likely because they achieve deeper poses and recruit more muscle.
Calorie Burn Compared to Regular Yoga
Hot yoga burns considerably more calories than a standard unheated class. A 160-pound person can expect to burn roughly 477 calories in a 90-minute hot yoga session. The same person doing hatha yoga at room temperature for the same duration would burn about 189 calories. That’s more than double the energy expenditure, driven by both the physical demands of the poses and the extra work your body does to cool itself.
Cardiovascular and Blood Pressure Effects
A clinical trial on adults with elevated blood pressure found that regular hot yoga practice lowered 24-hour systolic blood pressure by about 5 points (from 126 to 121 mmHg) and diastolic by about 3 points (from 82 to 79 mmHg). These reductions happened without blood pressure medication and without weight loss. The improvements showed up specifically in waking blood pressure, while sleeping blood pressure stayed the same. The control group, which didn’t practice hot yoga, saw no changes.
Stress and Mental Health Benefits
The mental health effects go beyond the usual post-exercise mood boost. In a controlled trial of heated hatha yoga, participants’ self-reported perceived stress scores dropped nearly in half over the course of the program. Among people who started with high stress-related cortisol spikes, those assigned to yoga showed significantly greater reductions in cortisol reactivity compared to a control group.
The same study found that yoga participants reported meaningful decreases in binge eating frequency and in eating as a way to cope with negative emotions. These shifts suggest that the practice affects how people regulate stress, not just how they feel in the moment. Other research on yoga in women has found improvements in anxiety, depression, emotional wellbeing, and disordered eating patterns.
Flexibility: Not as Different as You’d Think
One of the most common reasons people try hot yoga is the promise of deeper stretching. And the heat does make it feel easier to sink into poses. But a systematic review of the research found something surprising: hot yoga doesn’t appear to increase joint range of motion beyond what regular (unheated) yoga achieves. Only one out of thirteen flexibility measures showed a difference between hot and room-temperature yoga. You may feel more flexible in the moment, but over time, your gains are likely comparable to what you’d get from a cooler class.
Risks and Who Should Avoid It
The biggest risk is heat-related illness. Losing 1.5 liters of sweat in a single session means dehydration can set in quickly, especially if you didn’t drink enough beforehand. Symptoms like dizziness, nausea, or a sudden headache during class are signals to stop, sit down, and cool off.
The feeling of increased flexibility in the heat can also work against you. When muscles and connective tissue feel unusually pliable, it’s easier to push past your actual safe range of motion and strain something. Moving slowly and respecting your body’s limits matters more in a hot room than in a cool one.
Hot yoga is not recommended for people who are pregnant or who have a heart condition. The heat can also worsen asthma symptoms. If you have any of these concerns, a room-temperature yoga class offers many of the same benefits without the added cardiovascular and thermoregulatory stress.
Preparing for Your First Class
Drink plenty of water in the hours before class, not just right beforehand. Bring a large water bottle and a towel for your mat, because your hands and feet will get slippery. Wear light, moisture-wicking clothing. Eat a light meal at least 90 minutes before class so you’re not digesting heavily in the heat.
Expect to feel intensely warm and possibly lightheaded during your first session. Many studios encourage new students to take breaks, sit or lie down when needed, and simply stay in the room rather than pushing through every pose. Your body adapts over multiple sessions. Experienced practitioners handle the heat more efficiently, sweating more effectively and tolerating higher core temperatures with less discomfort.