Hot tub offers similar benefits to running, say researchers

A half-hour soak in a hot tub can bring the same health benefits as going for a 30-minute run, according to British researchers, but they caution it’s no reason for runners to let good exercise habits go down the drain.

In a study reported by The Sun newspaper, researchers from the University of Coventry have examined the overlapping positive impacts of relaxing in a hot tub and running.

“As a researcher, I am interested in exploring ways to improve people’s lives through lifestyle modifications,” Tom Cullen, assistant professor of research at the Coventry Centre for Sport, Exercise and Life Sciences, told The Sun.

“Many typical modifications such as exercise, dieting and quitting smoking are often difficult for many people to maintain for a variety of reasons,” he said, adding that soaking in a hot tub “offers an excellent way of providing a lifestyle modification that has many health benefits, but crucially, is something which people enjoy doing.”

The study involved 20 participants, ranging from 26 to 60 years old, who were immersed in a hot tub for three 30-minute sessions at different times over three days. Researchers recorded several health metrics, including blood pressure, heart rate, blood flow, anxiety and mood.

They found that after a half hour in the hot tub, participants experienced an average 345 per cent increase in blood flow to the legs, which the researchers said is comparable to the results of a 30-minute easy run. Heart rates increased by an average 41 beats per minute, roughly the increase produced by a brisk walk, according the scientists.

The study also showed participants’ blood pressure dropped after the soaking sessions, and that salivary cortisol levels—an indicator of stress—fell an average of 22 per cent, similar to the results from exercising over the same amount of time.

Although the study identified several overlaps in health benefits between relaxing in a hot tub and going for a run, the researchers aren’t suggesting that runners throw in the towel and swap their workout sessions for leisurely soaks.

Hot bath or hot tub post-workout provides heat acclimation, study shows

In a previous review of studies that explored overlaps between the benefits of passive-heating activities—such as soaking in a hot tub, bath or a sauna—and aerobic exercise, Cullen and colleagues concluded “passive heating does not appear to confer all the important benefits of exercise and potentially not to the same degree in all cases.”

They noted exercise “should be considered as the primary route for maintaining and improving health,” adding that “passive heating may be a promising therapy in those who display poor exercise adherence.”