Does taking a hot bath really burn as many calories as taking a thirty-minute walk? The answer is a definite maybe. You have to believe that all the sauna and hot tub aficionados out there are onto something, especially since sauna is practically a national sport in Finland. Unfortunately, the only recent scientific study dealing with this question used a statistically small group and the participants were all male. But there are hints that taking a hot bath can have positive health effects and yes, it does burn a few more calories than just hanging out.
How Does a Hot Bath Burn Calories?
The hot bath study by Dr. Steve Faulkner of Lough borough University attempted to measure the number of calories burned, blood sugar levels, and inflammatory response in the subjects that took part. Soaking in a hot tub dilates blood vessels, increasing oxygen absorption by the body. Since it takes calories to burn oxygen, there's an increase in the number of calories you burn. In the study, the aim of the hot bath was to increase core body temperature by one degree centigrade.
What Are the Other Health Benefits?
One interesting finding from the study is that a hot bath can help keep blood sugar stable. Twenty-four hours after soaking in a hot bath for an hour, blood sugar levels were measured in each of the participants. The control group, which rode bicycles for an hour, was subjected to the same twenty-four-hour measurement. Peak blood sugar levels were ten percent lower in the bathers than in the cyclers.
Scientists refer to raising the body temperature in this way as 'passive heating', and the study showed that it triggers the anti-inflammatory response, something that also happens when we exercise. The anti-inflammatory response in the participants was similar whether they took a hot bath or rode a bike. Since inflammation is the cause of many illnesses, this is a significant finding. In 2015 another study, also with only men, indicated that spending time in saunas can lower the risk of heart attack or stroke.
As far back as 1999, studies have been undertaken regarding passive heating. Philip Hooper of McKee Medical Center in Colorado did the first group study, and he used subjects that had Type II Diabetes. The diabetics in his study showed improvement in blood sugar levels and even a reduced dependence on insulin. Some of the subjects also lost weight. While exercise is recommended for good heath, McKee concluded that hot tub therapy could provide some of the same benefits for patients who were unable to exercise.
How Does a Hot Bath Improve Your Health?
Scientists believe that the mechanism that produces these encouraging results is the manufacture of more heat shock proteins in the body. These proteins rise in response to stress, whether it's caused by exercise or overheating. One clue that supports this theory is that Type II diabetics have fewer heat shock proteins in their blood. The dilation of blood vessels and increased blood flow from a hot bath is also beneficial to diabetics and to anyone with high blood pressure.
One thing you have to remember, though, is that these benefits don't improve muscle tone and lung capacity like exercise does. Getting regular exercise also benefits the body by boosting the good HDL cholesterol and reducing the unhealthy triglycerides in your blood. The Mayo Clinic recommends that people either moderately exercise for 150 minutes per week or have an intense workout for half that amount of time.
The Verdict on Hot Baths
So, what's the bottom line? You can lose the same 140 calories by soaking for an hour in a hot tub as you can by taking a 30-minute walk. Both activities are good for you in different ways, and neither one should replace the other exclusively. One interesting note about the hot bath studies is that the water temperature was roughly 104 degrees Fahrenheit, the same as in most hot tubs. That sounds like justification for buying one for your deck or patio!