When I am in a Hot Yoga session – I know that I will sweat. My clothes and sometimes my yoga mat are soaking by the end of the practice. You need to keep hydrated to stay healthy. It begs the question – how much do you sweat during a hot yoga session?

Scientists at the Central Washing University and University of Georgia undertook a study to investigate the pre-exercise hydration status, fluid balance  in hot yoga participants. This was motivated because it is known that sport participants often begin competition or practice in a hypo-hydrated state. They reasoned that hot yoga participants could be at risk for dehydration due to the nature of the environment they practice in, which could be compounded by their pre-exercise hydration status.

They took male and female participants about 30 yrs of age of medium height and build. Participants were examined during a one – hour hot hatha yoga class at 38 °C (100 °F). Their urine specific gravity (USG) was taken prior to class to assess the participant’s pre-exercise hydration status. Sweat rate was calculated using pre and post session weight and fluid intake.

They found that about a quarter of the class participants began hot yoga under hydrated. On average the participants’ sweat rate was one liter per hour! Despite free access to fluids during class, their consumption was low (1/4 liter per hour) and a third did not consume any fluids. Consequently, as a result of fluid loss about half of the participants lost at least 1% of body mass.

The big conclusion of this study is that most hot yoga participants do not replace their fluids enough during their session. Those who start under hydrated are further dehydrated. This may increase the health risk for some participants. Therefore it is important to drink lost of fluids before entering the studio and drink sufficiently during the practice. A good tip for teachers may be to encourage drink breaks during the session.

Study:

Campbell, S.; Pritchett, R.C.; Justice, K.; Pritchett, R.L.; and Burnham, T.R. (2014) “FLUID INTAKE AND SWEAT RATE DURING HOT YOGA PARTICIPATION,” International Journal of Exercise Science: Conference Proceedings: Vol. 8: Iss. 2, Article 50.Available at: http://digitalcommons.wku.edu/ijesab/vol8/iss2/50

Photo from: Acefitness study who also warns of staying hydrated