Dr. Steve Faulkner, a researcher at Loughborough University, says bathing may have similar benefits to exercising, including helping to prevent type 2 diabetes.
He explained to The Conversation that, though a hot bath has always been relaxing, it's only recently that science has begun to discover how "passive heating" can improve health.
Dr. Faulkner and his team have investigated the effect of a hot bath on blood sugar control and the number of calories burned. The study involved 14 people each enjoying an hour-long soak in a bath run at 104 degrees Fahrenheit, as well as heading out on a hour-long bike ride.
The two tests were designed to raise core body temperature by just one degree so that the team could measure how many calories were burned in each session.
Though biking did burn more calories, they found that a hot bath used up as many calories as a 30-minute walk.
"The overall blood sugar response to both conditions was similar, but peak blood sugar after eating was about 10% lower when participants took a hot bath compared with when they exercised," Dr. Faulkner reports.