With temperatures ranging from 90 to 105 degrees, it's no wonder some question the safety of a hot or Bikram yoga class, especially in terms of dehydration, heat exhaustion and muscle damage. But a new study from the American Council on Exercise says that there's no difference in the increase to your core body temp and heart rate, whether you're taking regular or hot yoga.
“Any time exercise is conducted in extreme temperatures, it’s important to remain hydrated and to watch for signs of overheating,” says ACE chief science officer Dr. Cedric Bryant. “However, this study showed that while higher sweat levels may cause participants to feel like they were working harder, heart rates showed they were actually at comparable levels whether in the regular or hot yoga class.”
The study, conducted by the University of Wisconsin-La Crosse's Department of Exercise and Sport Science, studied 20 healthy, relatively fit men and women, 19-44, who tried 60-minute hot yoga and regular yoga classes. The highest core body temperature recorded by a participant was 102.4 degrees, whereas concerns about fatigue and heat-related illness only really develop when the body reaches 104 degrees. Despite almost equal heart rates in hot yoga and regular yoga classes, the participants rated the the hot yoga class as more challenging based on RPEs.
“For those looking to participate in hot yoga of any kind, it’s important to properly hydrate before, during and after class while also monitoring for early signs or symptoms of heat intolerance (e.g., headache, muscle cramps, nausea, dizziness or fatigue),” Bryant says.
Bryant adds that the study was conducted at a hot yoga class of 92 degrees, but that since many hot yoga classes can reach 105 degrees or higher (and can last longer), more research needs to be done.