Why Does Hot Yoga Raise My Number?
I am a 62-year-old woman with type 2 diabetes; my A1Cs range from 6 to 6.7 percent. I started Bikram (hot) yoga recently, and I really enjoy it. I normally attend the 90-minute session in the morning before I eat anything because Bikram recommends that you not eat for two to three hours before a session. After moderate exercise, my glucose reading normally comes down about 30 to 40 points. With Bikram, it is 20 to 25 points higher. Why? Is such strenuous exercise safe for me? Name Withheld
Bret Goodpaster, PhD, responds:
What to Know: Different types of exercise may influence your blood glucose in very different ways. It is well known that both the intensity and duration of the exercise are key reasons for blood glucose levels going either up or down.
There are several possible explanations of why your blood glucose could be elevated with longer-duration, more strenuous exercise such as Bikram yoga. During this more strenuous exercise in the heat, it is likely that your body is producing more of the "stress hormones" such as epinephrine (aka adrenaline) as well as glucagon, which can certainly raise blood glucose. What's more, heat, humidity, and possible dehydration can act as additional stresses. Elevation in blood glucose with this type of strenuous exercise is a normal hormonal and stress response.
Find Out More: While a rise of 20 to 25 points in blood glucose might not be dangerous, it partly depends on your glucose level at the start of exercise. I would advise against this type of strenuous workout if your fasting blood glucose is near 300 mg/dl. If, however, your blood glucoses are not going into the 300-plus range even after the workout, and your doctor has indicated that you are otherwise healthy to exercise, this type of yoga may be OK. The long-term health benefits of intensive exercise may outweigh a small, temporary elevation in blood glucose levels.
Takeaways: Congratulations on getting regular exercise! While you may enjoy Bikram yoga, there are frankly too many unpredictable variables involved (high intensity, heat, humidity, possible dehydration) for me to be able to say unconditionally that this particular form of exercise is absolutely safe for you.