‘Hot yoga’ doesn’t need to be hot to achieve vascular benefits

Bikram yoga—a form of “hot yoga” in which poses are practiced in a room heated to upwards of 104 degrees Fahrenheit (40 degrees Celsius)—has cardiovascular benefits, but no more than yoga practiced at room-temperature, teams at the University of Texas at Austin and Texas State University  have found.

Yoga has seen an influx of scientific support in recent years, as it’s proven to help lower blood pressure, cholesterol and blood sugar, according to Harvard Health. Its resume also boasts a promise of improved body image, better weight control and increased mindfulness. Bikram in particular has been heralded as an effective weight loss strategy, since the combined heat and movement lead participants to sweat more heavily during the 26-pose routine.

Stacy D. Hunter, PhD, and colleagues found these benefits in a group of individuals enrolled in a hot yoga class—but they weren’t a result of the temperature.

“The new finding from this investigation was that the heated practice environment did not seem to play a role in eliciting improvements in vascular health with Bikram yoga,” Hunter said in a release from the Physiological Society. “This is the first publication to date to show a beneficial effect of the practice in the absence of heat.”

Hunter and her team analyzed the effects of hot Bikram versus yoga in thermoneutral conditions in a cohort of 52 sedentary, but healthy, middle-aged adults. Participants were split into three groups: one assigned to a traditional Bikram class three times a week, one dedicated to practicing Bikram yoga at 23 degrees Celsius and one group that remained sedentary for the duration of the trial. The researchers used brachial artery flow-mediated dilation to measure individuals’ endothelium-dependent vasodilation.

Apart from body fat percentage—which was significantly lowered in the hot yoga group—there was little difference in vascular function between the two yoga groups.

“These novel findings highlight the effectiveness of hatha yoga postures alone, in the absence of a heated practice environment, in improving vascular health and are of clinical significance given the increased propensity toward heat intolerance in aging adults,” the authors wrote.

Hunter et al.’s findings were published in Experimental Physiology this week.