How can we get the benefits of exercise without actually exercising? The fitness experts of the last century had two ways of marketing their workouts. These were through programs or devices that were either so easy a child could do it, or they pushed you to experience limits you didn’t think possible. Following that workout it was advised to use a hot tub or hot sauna to increase the calorie burn after working out, and it seems they were on to something.
There is now research that confirms more calories are burned when your body temperature rises in a hot bath, but also has a surprisingly beneficial effect on your blood sugar.
Exercise physiologist Steve Faulkner, PhD., headed a pilot study that measured the effect of raising core temperature on blood sugar levels and calories burned. They used a small group of volunteers that were fitted with devices to monitor blood sugar, equipment to measure calories burned and rectal thermometers to measure their core body temperature. Phase one was to use a hot bath that was kept at a steady 104 degrees until the body temperature had risen and stabilized. Next they had an hour of exercise on a stationary bike. They found that energy expenditure increased by 80% sitting in a hot bath for an hour. The hot bath didn’t approach the energy expenditure as from the exercise bike for an hour. The bike burned 630 calories and the hot bath burned 140 calories in an hour.
The next factor they evaluated was the peak glucose output, or rise in the blood, after a meal. They all ate a meal of similar composition a couple of hours after their hot bath and after exercising for an hour. Blood sugar levels after a meal is a risk marker for type 2 diabetes and metabolic syndrome. Your pancreas secretes small amounts of insulin throughout the day, if you don’t have diabetes, in response to the amount of blood glucose and other factors. The amount of glucose rises in your blood as your body becomes more resistant to insulin. All volunteers were healthy individuals without a history of diabetes.
The peak glucose was actually quite a bit lower after the bath, compared with exercise. Also, the post-meal glucose levels were actually 10% lower after a hot bath than an hour of exercise.
There are other health benefits of heat from hot baths and saunas. Sweating during exercise in a hot tub or sauna may help excrete heavy metals and other toxic elements. Saunas increase your heart rate and expends calorie burning as well as increasing the secretion of growth hormones that are essential to muscle growth and health maintenance. Your core temperature will also be increased with use of a sauna. This doesn’t even cover the deeper and more relaxed sleep you will gain from a sauna use and the relief of chronic stress symptoms.
Some safety considerations would be to make sure the water is filtered, drink plenty of water, use a cool rag over your head if you experience a headache after a sauna use, steer clear of the sauna if you are trying to have a baby, and don’t raise your core temperature above 104.8 degrees. Staying in a sauna too long can cause severe dehydration and can lead to death. Try to sauna with a buddy for safety.
Get out there and enjoy that sauna or hot tub but do so with sense (and a buddy). If you have specific medical conditions, it might even be well to consult with your medical provider before engaging in regular hot tub/sauna exercises.
-Dr Fredda Branyon