When practiced regularly, there's evidence that Bikram yoga can do a body good. A 2013 study from Colorado State University researchers found that adults who participated in three Bikram sessions a week for eight weeks showed increased strength, improved flexibility and slightly decreased body fat compared to a control group. (They did not, however, show any change in cardiovascular or aerobic fitness.) [Source: Tracy] And in a 2008 study, also from Colorado State, a regular Bikram practice was associated with improved balance, leg strength and muscle control, as well. [Source: Hart]
Choudhury claims that being in a heated room allows for more flexibility and looser muscles -- but this can have risks as well as benefits, says Herbert. "It really does allow you to stretch further than you would be able to in a colder room, but for someone who's already hyperflexible, that could actually be detrimental. If you're not careful, you can hyperextend and injure yourself."
The heat brings other potential dangers with it as well, especially for people who may be dehydrated or who have underlying health conditions. If you feel dizzy, lightheaded or sick to your stomach during class, stop and take a break. In addition to the risk of heatstroke or another heat-related illness, you're also more likely to injure yourself by slipping and falling if you feel this way. [Sources: Aldonas, Martin] And here's something you may not have thought of: Not drinking enough water before or after class can cause obvious problems -- but so can drinking too much. In 2012, the British Medical Journal reported on a woman who drank 3.5 liters of water after a Bikram class and suffered breathlessness, nausea and stomach cramps -- and eventually, seizures -- related to hyponatremia, a dangerous deficiency of sodium and electrolytes related to profuse sweating and drinking too much water. [Source: Reynolds]
Still not sure if Bikram is for you? "As long as you're aware of the precautions about the heat and you don't have any medical reasons not to, you should go ahead and try it," says Herbert. "Some people will absolutely love it, and for others, it's not for them. But it's definitely an interesting experience, either way."