medicine
Soaking in a Hot Tub Bestows Surprising Health Benefits, Even More Than Saunas
Oregon researchers found a simple hot bath — accessible to almost everyone — beat saunas for raising core temperature and boosting vascular and immune benefits.
Saunas are all the rage these days for exercise recovery and longevity, because the increased ambient heat triggers a cascade of effects in the body that can lower blood pressure and reduce inflammation.
But, how many of us have access to a sauna?
That’s why researchers from the University of Oregon compared the effects of saunas to a simple soak in a hot bath—which is much more accessible to most people—and found good news for the sauna-less masses.
The research was published in the American Journal of Physiology and the authors say it was the first time that three different heat therapies were compared.
“We compared the most commonly utilized modalities of passive heating as they’re used in everyday life and studied in scientific research,” said lead author Jessica Atencio, a doctoral student in the lab of Professor Christopher Minson.
There’s much more research into sauna bathing than hot tub bathing—and most of it comes from Dr. Jari Laukkanen, a Finish cardiologist, clinician, and research scientist who has produced robust, multi-year studies on saunas—which are far more popular in Finland than elsewhere.
In the Oregon study, researchers monitored body temperature, blood pressure, heart rate, cardiac output (the amount of blood the heart pumps per minute), immune cell populations, and blood biomarkers of inflammation. Data was collected before, during and after subjects soaked in a hot tub, sat in dry heat, or tried far-infrared saunas.
The study looked at 10 men and 10 women who exercised regularly and ranged in age from 20 to 28 years old. The goal was to isolate the physiological responses to each heating method in a young, healthy population.
“We saw that hot water immersion was the most impactful in increasing core body temperature, which is the main stimulus for these subsequent responses,” Atencio told the University of Oregon press.
“Increasing body temperature causes an increase in blood flow, and just the force of blood moving across your vessels is beneficial for your vascular health.”
While the research team took blood samples from subjects after each kind of heat therapy, only hot-water immersion produced an inflammatory response as measured by the levels of inflammatory cytokines, a kind of immune signaling molecule, and immune cell populations.
Atencio and her team were not surprised by those results.