Among certain folk fond of tight-fitting activewear, the form of exercise known as Bikram yoga is extremely popular.
Named after its founder, Bikram Choudhury, it has been practised around the world since the 1970s. Bikram involves elements of the decidedly older form known as hatha yoga, with the principal difference that it is carried out in a room heated to a sweat-inducing 35 to 42 degrees Celsius.
As a selling point, the addition of extreme heat it has been very successful. One estimate suggests Choudhury has more than 900 franchised studios around the globe.
Part of the popularity of the Bikram hot yoga discipline is the claim that it improves general health, muscle strength and flexibility.
Now, however, a study led by Stacy Hunter from Texas State University in the US has found that while yoga itself delivers some benefits – reducing changes in the lining of blood vessels, for instance, thereby lowering the risk of heart disease – doing it in a very hot room makes not a jot of difference.
Hunter and her colleagues tested 80 volunteers, dividing them into three groups. The first was a control cohort that sat around and relaxed, the second did hatha poses at room temperature, while the third went the full Bikram. All groups did three 90 minute classes a week for 12 weeks.
The results were interesting. Both the room temperature group and the hot group recorded identical improvements in blood vessel dilation – meaning that heat was not a factor in the result.
“These novel findings highlight the effectiveness of hatha yoga postures alone, in the absence of a heated practice environment, in improving vascular health,” concluded Hunter’s team in a paper in the journal Experimental Physiology.
The researchers also suggested that this was of clinical significance “given the increased propensity toward heat intolerance in aging adults”.
The research is not without other potential benefits, as well. Room temperature yoga is, prima facie, more environmentally friendly than yoga carried out in a space with electric heaters pumping. And it means that your Lorna Jane Beverly Hills Workout gear won’t stink to high heaven on your way home.