Can you get the benefits of exercise without exercising? In the last century, as more people moved off small, family-owned farms to live in large cities and towns, the exercise they experienced decreased dramatically. Over the next several decades, an entire exercise industry emerged.

New fitness experts had two ways of marketing their workouts. The programs or devices were either so easy a child could do it, or they pushed you to experience limits you didn’t think possible.

Using a hot tub or hot sauna after a workout was one of the strategies some used to increase their calorie burn after working out. Apparently they were on to something.

Recent research confirms that not only are more calories burned when your body temperature rises in a hot bath, but it also has a surprisingly beneficial effect on your blood sugar.

Hot Baths, Exercise and Energy Expenditure

An initial pilot study by exercise physiologist Steve Faulkner, Ph.D., measured the effect of raising core temperature on blood sugar levels and calories burned.¹

A small group of volunteers were fitted with devices to monitor blood sugar, equipment to measure calories burned and rectal thermometers to measure core body temperature.

The first phase used a hot bath kept at a steady 104 degrees Fahrenheit (40 degrees Celsius) until the volunteer’s body temperature had risen and stabilized. The second phase used an hour of exercise on a stationary bike.

The researchers found energy expenditure increased by 80 percent sitting in a hot bath for an hour. This didn’t approach the energy expenditure from riding a bike for an hour, but was extremely close to a brisk 30-minute walk. Riding the bike burned 630 calories and the hot bath burned 140 calories in an hour.2