The act of soaking in a natural hot spring, sometimes called hot potting or hot water immersion therapy, is known as balneotherapy in a therapeutic and complementary health context.
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These waters can be found in a variety of settings, from naturally occurring outdoors to being directed into pools at spas and wellness resorts.
Because the waters originate from deep within the earth, they accumulate minerals on their way to the surface, explains Marcus Coplin, ND, a primary care naturopathic physician in Seattle, and the director of hydrothermal medicine for the Balneology Association of North America.
The result? Water that is rich in minerals that may provide health benefits, such as calcium, magnesium, potassium, and sulfur. Sometimes these waters arrive at the surface naturally heated; other times, these mineral-rich waters are cold, then heated artificially.
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Every hot spring offers a unique makeup of minerals, but there are benefits to soaking in warm or hot water regardless of the content of the minerals, says Krista Ingerick, a licensed massage therapist and the spa operations manager at the Springs Spa, a wellness center that provides integrative therapies for Clifton Springs Hospital and Clinic in New York. “In general, most people enjoy soaking for the relaxation and pain-relieving effects, so arriving with the mindset that you’re ready to tune out to the outside world and the stress of daily life is the first step,” Ingerick adds.
1. May Provide Potential Pain Relief
“The heat of the water helps relax the muscles and can have pain-relieving effects,” Ingerick says. “Essentially, this therapy can act as a whole-body immersion heat pack.”
While there is no set temperature, hot springs ranging from 98 to 106 degrees F are generally considered comfortable and safe for most adults.
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Research suggests that hot potting may offer pain relief for people who have arthritis and other pain conditions. In a study that looked at nearly 1,300 people with joint or muscle pain, including from rheumatoid arthritis, 83 percent said that bathing in a hot spring provided relief from their symptoms by the end of the bath.
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Other research suggests hot potting may help improve chronic lower back pain, particularly in adults 60 and older.
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Still, it’s important to understand the role of hot springs within the overall conventional medical management of disease and adjust expectations as necessary. In a study of 126 individuals, many participants with musculoskeletal conditions had hoped that soaking would provide a permanent cure, which was not the case. Others also noted that this was something they had to do regularly since pain-relieving effects were only temporary.
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Indeed, hot potting may become just one part of a comprehensive treatment plan. “One thing I do want to caution is that I don’t want it to sound like if you have arthritis, you can soak in hot springs and be fine,” Coplin says. “Though it is effective [as a complementary therapy for some people], part of the efficacy is the proper application of prescription medication and physician monitoring.”
2. May Relieve Certain Skin Conditions
Minerals such as sulfur and magnesium have anti-inflammatory and antibacterial properties, and these and other minerals may be useful in treating some skin conditions, Ingerick says. A research review on the topic concluded that soaking in warm, mineral-rich water may benefit those who have psoriasis or eczema the most, with some perks for skin itchiness, acne, and seborrheic dermatitis, or an itchy, flaky scalp, thanks to the theorized anti-inflammatory effects of the minerals in waters like sulfur and manganese.
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3. May Help You Relax
Relaxation is one well-known potential benefit to hot potting. “The simple experience of soaking in a warm bath for relaxation can have profound effects by turning off our fight-or-flight stress response, allowing our bodies time to heal,” Ingerick says. She adds that relaxation is a nice antidote to fatigue and can help improve resilience in the face of stress.
One study of nearly 7,000 people in Japan, a country with thousands of mountains, many of which have hot springs, found a strong association between hot potting and improved mental health. The study authors note that being outside in nature may also play a role in the relaxing effects and purported mental health benefits of hot potting.
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4. May Support Weight Loss
Research suggests that the heat from a soak may increase your metabolic rate (this is, in part, the speed at which your body burns calories), lower markers of inflammation, and help regulate your stress response, Coplin says.
A small study of 14 men found that those who sat in a water bath burned an additional 61 calories per hour compared with a resting condition not in the water. (Exercise burned 556 calories per hour compared with rest, making it more efficient than either sitting at rest or soaking.)
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Another small study of 14 individuals with type 2 diabetes found that two weeks of regular hot water immersion sessions (four to five times per week) had some metabolic benefits, including improved insulin sensitivity, which can support weight loss.
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But the research in this area is limited and there’s no evidence that soaking in hot water directly leads to weight loss. Rather, it may be one tool in an arsenal of approaches to overall health and wellness. “While hot springs soaking can be a nice component of a comprehensive weight loss program, it is unrealistic to think you will soak and come out 20 pounds lighter,” Coplin says. “This is something you would do regularly in addition to a mindful-based diet and exercise program [under your doctor’s guidance].”
5. May Provide Cardiovascular Benefits
Research has shown that hot water immersion boosts cardiovascular function, including increased heart rate and improved blood flow.
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One cross-sectional study of 5,250 adults conducted in a small city in Japan found that residents who bathed in hot springs more than once per week experienced significant reductions in high blood pressure symptoms compared with those who did not.
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Another study of 24 middle-aged adults in the UK found that 30 minutes of aerobic exercise followed by 30 minutes of hot water immersion three times a week for eight weeks was associated with improved blood pressure and blood vessel health.
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One important thing to keep in mind if you are looking to use hot potting as a complementary therapy for any health condition: Hot soaking is not a substitute for routine conventional care. Additionally, soaking in hot water should be done cautiously or not at all during pregnancy to avoid potential risks to the developing fetus, especially in the first trimester. You might also need to avoid hot potting if you’re prone to seizures or have low blood pressure.
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Be sure to discuss your treatment goals and how immersion therapy may fit within them with your healthcare provider.
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The Takeaway
- Hot potting, or soaking in mineral-rich hot springs, may provide a number of possible health benefits, including temporary pain relief, improved relaxation and mood, relief from skin conditions like eczema, and support for weight management and heart health.
- While soaking in hot springs offers relaxation benefits, it’s not a replacement for a comprehensive approach, including diet and exercise, for achieving long-term weight loss or cardiovascular health.
- Always consult a healthcare provider to ensure that hot potting or any other complementary therapies fit safely into your overall healthcare plan.
