Ahhh, there’s nothing more relaxing than a hot bath. You can almost feel the tension melt away as the warm water soothes your muscles and you sink into its luxurious warmth. But apart from relaxing you, there’s more to a hot bath than you might imagine.
A study by exercise physiologist Steve Faulkner of the UK’s Loughborough University tracked 14 men for the study. The participants were given two tests: to ride a bicycle for one hour and to lie in a 104-degree Fahrenheit bath for an hour.
The goal of the study was to try to increase the men’s core body temperature by one degree. What the study found was that the cycling burned far more calories than the hot bath. But one surprising result was that lying in a hot bath actually burned an amazing 130 calories.
This is about as much energy as you burn when taking a 30-minute walk, which sounds like good news to those of us who prefer something less strenuous than hitting the gym.
Blood Sugar Level
The researchers also tracked the men’s blood sugar during the study and found something very interesting. The participants’ peak blood sugar level was about 10 percent lower when taking a hot bath than when riding a bike. They also discovered that the hot bath appeared to have the same effect as the exercise in one important way: Both caused a similar anti-inflammatory response in the participants.
According to the study, passive heating such as lying in a hot bath for an hour can help to reduce inflammation. The practice of passive heating as a medical treatment is new to most of the world except for Finland, where people are known for regularly frequenting saunas. In fact, a study published in the JAMA Internal Medicine Journal in 2015 claimed that spending time in the sauna might help to prevent cardiovascular disease.
But why does passive heating cause the burning of calories? Faulkner believes that “heat shock proteins” are the reason. It turns out that we produce these particular proteins during exercise as well as during passive heating, where the body temperature is raised in a way that is independent of exercise.
The body produces these proteins in response to stress. According to Faulkner, the raised levels of these proteins on a long-term basis might be able to help the functioning of insulin and assist with controlling blood sugar. In fact, the levels of these proteins are lower in people with diabetes. Maybe passive heating will become useful to people with type 2 diabetes in the future.
In the meantime, don’t swap your exercise routine for hot baths just yet. The study’s sample size was very small, so further research is required — as is research with women rather than only men.
Increase your heat shock protein levels by regularly exercising and enjoying a hot soak afterward to ease muscle pain and do wonders for your psychological health. Studies from Yale University show that taking a warm bath can provide the physical warmth of an embrace, reduce stress levels, increase levels of trust and generosity, and promote better sleep.