Measuring physiological changes in pregnant women during hot yoga
Abstract
One of the concerns surrounding the practice of hot yoga is a potentially dangerous increase in
core temperature, notably pregnant women. Previous research has shown that a core temperature
in excess of 102.2 ºF, or an increase in core temperature greater than 2.7-3.6 ºF from rest, may
result in abnormal fetal development. The main purpose of this study was to evaluate and
compare the core temperature responses in pregnant and non-pregnant women during a 60-
minute hot-yoga class. Four pregnant and five non-pregnant women served as subjects and all
subjects were regular participants in hot yoga. Prior to the class, subjects ingested a CorTemp
Ingestible Core Body Temperature Sensor (HQ Inc, Palmetto, FL). Core temperature was
recorded every 10 minutes during the class. Room temperature and humidity averaged 95.7ºF
and 56.7% respectively, during the class. The highest core temperature recorded during a class
averaged 99.5 ºF in the pregnant subjects and 99.9 ºF for the non-pregnant subjects. The highest
single core temperature in a pregnant subject was 100.1 ºF, while one non-pregnant volunteer
reached 101.4ºF. None of the pregnant subjects had a change in core temperature during a class
in excess of 1.2ºF and the largest change for a non-pregnant subject was 2.8 ºF. Based upon the
results of this study, it appears that women who are participating in hot yoga at the time of their
pregnancy can safely continue their practice. However, it is still not recommended that women
start a yoga practice after they become pregnant.
Subject
Kinesiology
Exercise -- Physiological aspects
Yoga
Pregnant women