I am often tempted to fill the tub and take a long, hot soak. But then my kids scream and remind me how naïve I am to think I can enjoy such pleasures. Taking a bubble bath with kids around is about as relaxing as trying to do anything with kids around. Even if they are asleep or out of the house, I feel guilty about wasting water in an attempt to take time for myself while sitting in my own stew. Science is helping me reframe the way I view hot baths, however. If I call it “passive heating” I can call it a supplement to healthy living. That’s right, friends: sitting in a tub of hot water offers the benefits of a gentle workout.
There is no arguing that exercise is good for us; it provides both mental and physical health benefits. Boosting our mood while reducing the risk of cardiovascular diseases, some cancers, and diabetes seems like a no-brainer. However, not everyone can exercise. Chronic pain and physical limitations make it difficult for some folks to move in ways that would provide the boosts they need to their brain and body. Researchers are examining the benefits of passive heating: raising the body’s core temperature through sedentary acts like soaking in a hot bath, hot tub, or sauna. The findings are cool.
A study done at Loughborough University measured and compared the body’s blood sugar control and energy expended after both an hour long soak in a hot tub or an hour long bike ride. The cycling burned more calories, but the overall blood sugar response was nearly the same. After eating, however, the peak blood sugar measurements were ten percent lower in folks who were in the hot bath vs. the folks who biked. While I am not suggesting a bath is better than a bike ride, evidence in this case is suggesting that it is better in some ways. Do what you will with that information.
Another benefit of exercise is inflammation reduction, which seems counter-intuitive. Movement actually creates inflammation, but then our body’s anti-inflammatory system kicks in. For those who don’t have a strong anti-inflammatory system, though, chronic inflammation settles in and leads to pain, arthritis, obesity, and diabetes. If exercise causes pain which contributes to more pain, I don’t think I would want to move my body much either. But folks can force their temperatures to increase with outside forces and still get some of the anti-inflammatory benefits.
Research has shown that hot water immersion treatments raise the levels of the inflammatory chemical called interleukin. Nitric oxide in the blood increased too. This improves blood flow and the movement of glucose through the body; the body’s tissues’ ability to take up glucose improves as well, which is vital for people with type 2 diabetes. Inflammation and type 2 diabetes are closely linked. People with type 2 diabetes have elevated levels of cytokine inside fat tissue which causes inflammation and reduces the body’s ability to appropriately regulate insulin. When the body becomes resistant to insulin, inflammation results and the dangerous cycle continues. While passive heating can’t cure diabetes or replace anti-inflammatory diet and exercise, it can help.
Anyone else as fascinated as I am? I am drawing a hot bath right now.
The nitric acid I mentioned earlier that causes blood vessels to dilate and blood pressure to drop is why pregnant folks are supposed to avoid hot tubs; if the body gets too hot a person can experience hyperthermia. This increases the pregnant person’s already high risk of dizziness, dehydration, and low blood pressure. But for a person at risk for high blood pressure, passive heating can improve cardiovascular health. One study compared the effects of passive heating on a body to what happens when our temperature rises while running on a treadmill; results showed that heart rate peaked at a lower rate during water immersion but femoral artery rate was higher than after treadmill use. Both signaled beneficial cardiovascular effects.
An interesting fact about hypertension in what the study called “young people” was that while exercise is a primary treatment for high blood pressure, it doesn’t have much or any effect on this population. However, studies found that heat therapy is capable of lowering blood pressure in “young, normotensive individuals” and can “prove more powerful than exercise alone as a treatment for hypertension.”
A hot bath may be just what your body needs right now. Perhaps you are too tired or sore to exercise; you don’t have the physical or emotional strength to do more than sit. That is totally okay. Passive heating shouldn’t replace that workout, walk, or bike ride all of the time, but it offers many benefits when we can’t get ourselves to move. Also, hot baths help us sleep better, relieve joint, muscle, and headache pain. Labor pain is reduced using water immersion. A bath can help us balance our hormones and improve our urinary tract and gastrointestinal health.
Put the kids in front of a movie, grab a book, some bubble bath or essential oils if that’s your thing, and enjoy the benefits of passive heating in the privacy of your bathroom. If you have a hot tub, get your money’s worth. I don’t have one, but I can call it an investment in my health if I purchase one, right? We can all benefit from lower blood pressure, improved health, and better sleep right now. Happy soaking, friends.
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