Hot yoga sits in a gray zone: your heart rate climbs into cardio territory, but the reason it climbs is more complicated than it seems. A typical hot yoga session pushes your heart rate to around 68–75% of your maximum, which lands squarely in the moderate-to-vigorous cardiovascular zone. But much of that elevated heart rate comes from your body fighting the heat, not from the physical demands of the poses themselves.
What Your Heart Rate Actually Does
During a hot yoga class, your average heart rate typically reaches 75% of your predicted maximum, with peak heart rates hitting 85–92% depending on sex. One study on power yoga found participants spent roughly 74% of the class in moderate-to-vigorous heart rate zones. By the American Heart Association’s definition of aerobic activity (exercise that gets your heart rate up and improves cardiorespiratory fitness), those numbers look like cardio on paper.
Here’s the catch. When researchers measure the actual metabolic cost of hot yoga, a session only demands about 25–31% of your maximum oxygen capacity. That’s a remarkably low level of physical exertion for how hard your heart is working. For comparison, brisk walking typically demands 40–50% of your max oxygen capacity.
Why the Heat Tricks Your Heart Rate Monitor
Your heart rate during hot yoga is driven by two forces: the muscular effort of holding poses and your body’s response to extreme heat. In a room heated to 105°F (40°C), your cardiovascular system has to work overtime to cool you down. Blood gets redirected toward the skin for heat dissipation, your core temperature rises (peaking between 38.2 and 40.1°C in a 90-minute Bikram class), and your heart compensates by beating faster. This is thermoregulation, not aerobic conditioning in the traditional sense.
A systematic review in Sports Medicine confirmed this directly: hot yoga increases core temperature, heart rate, and sweat rate, but does not increase the energetic demands of the activity compared to the same yoga done in a cooler room. The predominantly static poses simply aren’t intense enough to elevate energy expenditure the way running, cycling, or swimming would. When researchers compared calorie burn between a one-hour Bikram sequence at 105°F and the identical sequence at 74°F, the results were nearly identical: 156 calories in the heat versus 151 at room temperature.
How Hot Yoga Stacks Up by Exercise Guidelines
The standard measure of exercise intensity is the MET, or metabolic equivalent. Light activity falls below 3 METs, moderate activity ranges from 3 to 6, and vigorous activity starts above 6. A broad review of yoga research found that yoga practice averages about 3.3 METs overall, with most individual poses classified as light intensity (below 3 METs). Sun salutations are the notable exception, reaching into the moderate-to-vigorous range.
That means a hot yoga class built heavily around flowing sequences and sun salutations can qualify as moderate-intensity exercise. A slower, more static Bikram-style class likely won’t, despite how sweaty and breathless you feel. The style of hot yoga matters more than the temperature of the room.
It Can Still Improve Cardiovascular Fitness
Despite the relatively low metabolic demand, the heat itself appears to provide a genuine cardiovascular training stimulus. A four-week study comparing hot yoga (three sessions per week) to the same yoga at normal temperature found that only the hot yoga group improved their maximal aerobic capacity. Their VO2 max, the gold standard measure of cardiovascular fitness, increased significantly, while the room-temperature group saw no change. Researchers attributed this to the added cardiovascular stress of heat, which forced the heart and blood vessels to adapt even though the poses themselves weren’t particularly demanding.
This is an important distinction. Hot yoga may not burn calories like a spin class, but the combination of moderate physical effort and heat stress can trigger real cardiovascular adaptations over time, particularly for people who are relatively sedentary or new to exercise. If you’re already a trained runner or cyclist, hot yoga is unlikely to push your aerobic ceiling higher.
How It Compares to Traditional Cardio
A 60-minute hot yoga session burns roughly 150–160 calories. A 60-minute brisk walk burns around 250–350 depending on body weight and pace. A moderate cycling session or jog burns 400–600. In terms of raw energy expenditure and sustained aerobic demand, hot yoga falls well short of traditional cardio activities.
Where hot yoga offers something different is in the combination of flexibility work, balance, strength in held poses, and heat-driven cardiovascular stress. It’s not a replacement for dedicated cardio if your goal is maximizing heart health or endurance. But it’s more cardiovascularly demanding than regular yoga, and for people who find traditional cardio unappealing, it provides a modest aerobic stimulus alongside its other benefits.
The Bottom Line on Counting It as Cardio
If your hot yoga class involves continuous flowing sequences, it can count toward the moderate-intensity physical activity guidelines (150 minutes per week). If it’s a slower, hold-each-pose style, the metabolic demand is closer to light activity, even though your heart rate suggests otherwise. The heat makes you feel like you’re working harder than you are, and your fitness tracker will reflect that illusion. For building a baseline of cardiovascular fitness, especially combined with the heat stimulus, hot yoga three times a week can produce measurable improvements. For anyone training specifically for endurance or heart health, it works best as a supplement to running, cycling, swimming, or other sustained aerobic exercise rather than a substitute.