Cardiovascular disease is the leading cause of death in the U.S. In fact, it has been previously predicted that by 2030, cardiovascular disease will affect more than 40% of the U.S. population. With this in mind, it seems clear that we—as a nation—need to improve our cardiometabolic health!
A brief glance at health magazines will lead you to believe there are a number of different ways to improve cardiometabolic health and that the newest exercise craze is always the best. Through all these fads—and a lot of them are good for you!—one simple truth persists: A healthy diet and some form of aerobic exercise are still the tried-and-true methods to help you stay healthy and prevent chronic disease. While it is convenient to believe everyone is capable and/or willing to exercise, that isn’t actually true or realistic.
Passive heating, or “thermal therapy,” has received renewed interest as a supplemental or alternative way to gain some of the health benefits associated with exercise. In fact, studies have found that increased frequency of sauna use reduces the risk of fatal cardiovascular diseases as well as all-cause mortality. Repeated heat exposure (for example, being in a hot tub) improves blood vessel health (vascular) and function in the average person. It also improves metabolic health in people who are overweight and boosts performance in elite athletes.
As a researcher now exploring vascular dysfunction in people with heart failure, I’m interested in activities that take less of an effort to improve cardiovascular health. My colleagues and I conducted a study that explored how hot tubbing may confer cardiovascular health benefits that are similar to exercise.
In our study, the volunteers, who were 23 years old on average, participated in two study sessions. In one session, they sat up to their chest in 104 degree F water for one hour. In the other session, they exercised on a stationary bike for one hour.
We found that exercise on the stationary bike worked the heart harder than hot tubbing. Yet, hot tubbing caused a sustained drop in blood pressure during the post-workout recovery period that was similar to what happened after exercise. This is important because post-exercise low blood pressure readings (called hypotension) are thought to play an important role in positive cardiovascular adaptations such as long-lasting reductions in blood pressure.
Our research team also found that hot tubbing changed the patterns of blood flow toward those that are associated with positive vascular adaptations as well or better—depending on the blood vessel—than after exercise. It appears that thermal stress from a hot tub may place a smaller burden on the heart than exercise while providing similar or greater vascular changes during recovery that are associated with improving cardiovascular health.
The bottom line: Thermal therapy should never replace exercise, but for those unwilling or unable to exercise, a hot tub could be your new home treadmill. So, if you can’t or don’t want to go for a run, jump in the tub and soak up the good health vibes.
Michael Francisco, PhD, holds a postdoctoral position at the Veterans Affairs Medical Center in Salt Lake City, where he is studying peripheral vascular dysfunction in heart failure patients. Francisco received his PhD at the University of Oregon, where he studied human cardiovascular responses to exercise and environmental stressors.