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5 Things Taking a Hot Bath Does to Your Body, Says Science

Sliding into a tub is definitely relaxing. But it also does wonders for your body and your health.
FACT CHECKED BY William Mayle

Few things on earth are quite as soothing as soaking in a nice warm bath after a long day. But the scientific connection between a hot bath and relaxation is more powerful than you may think. In fact, one study published in the journal Evidence-Based Complementary and Alternative Medicine found people who regularly hop into the bath instead of the shower tend to be less stressed and fatigued overall. What's more, they're more prone to smiling.

Despite the tranquility that hot baths provide, tens of millions of people would struggle to recall the last time they actually took one. Showers are much more common, and inveterate showerers will tell you that they simply don't have the time on most days to lay around in the bathroom for an extended period.

But the leading science makes a strong case for changing your bathing ways. So what does taking a hot bath really do to your body? Keep reading to find out. And for more on the science of your body, don't miss What Happens to Your Body When You Have Sex, According to Science.

You'll burn more calories.

Luxury black and white bathroom with freestanding bathtub, stylish mosaic tile floor and white doors with black handleShutterstock

That's right, lounging in hot water can actually cause you to burn more calories. Scientists in the UK report that sitting in a bathtub filled with 100 degrees Fahrenheit water for about an hour results in 130 calories burned. That's about equal to the number of calories usually burned during a half-hour walk.

While taking a bath for a full hour may be a bit too long for some, these findings in general are still quite noteworthy. What could be better than relaxing and getting in shape at the same time?

The exact reasons why a hot bath leads to calories burned are still a bit of a mystery. However, study author and research associate Steve Faulkner told Insider "a likely explanation for this is there is an increased energy demand to maintain heat balance." And for more on your incredible body, don't miss the Side Effects of Walking Just 10 Minutes Per Day, Says Science.

You'll fall asleep 10 minutes sooner.

woman sleeping in a cozy bed with a fluffy comforter and pillows
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Struggling with sleep lately? You may want to consider adding a warm bath about 90 minutes before bedtime to your evening routine. This research from of the University of Texas found that a hot evening bath using 104-109 degrees Fahrenheit water can significantly enhance sleep quality. Also: a hot bath can also reduce how long it takes to fall asleep by 10 minutes!

A hot bath helps with sleep because our natural circadian rhythms are tied to body temperature. A warm bath before hitting the sheets stimulates the thermoregulatory system, resulting in increased blood circulation and a drop in body temperature. The human body naturally cools down just before sleep, so in this way, a bath acts as a way of letting our bodies know that it's almost time for sleep. And for more ways to get better sleep, see here for The Sex Position That Secretly Helps You Get Better Sleep, According to a New Study.

Your breathing will improve.

woman breathing exercise on couch, concept of 4-7-8 breathing technique
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The heat and pressure that a warm bath places on one's chest can also benefit both lung capacity and oxygen collection. This is supported by tons of research dating back for decades, and steam intensifies this effect. This is especially useful while recovering from a respiratory infection like the flu, COVID-19, or just a stuffy nose.

Your heart disease risk goes down.

woman practicing mindful breathing
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One study published in the British Medical Journal says that a regular hot bath is linked to a lower risk of death from both heart attack and stroke. "We found that frequent tub bathing was significantly associated with a lower risk of hypertension, suggesting that a beneficial effect of tub bathing on risk of [cardiovascular disease] may in part be due to a reduced risk of developing hypertension," researchers write. (On a related note, other research suggests that a habitual date with your rubber ducky can mitigate diabetes risk factors.)

Your inflammation will drop.

inflammation concept
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Don't always have time for a workout? A warm bath can actually serve as a substitute for exercise in terms of inflammation and blood sugar control. When we're stressed, our bodies naturally become inflamed. Eventually, a number of anti-inflammatories are released to do away with all that inflammation, but many people's anti-inflammatory responses fall short of doing their job, leaving such individuals with chronic, low-grade inflammation.

While exercise is a great way to help the body do away with excess inflammation, a study from 2018 published in the Journal of Applied Physiology reports that a daily hot bath has a similar effect. And for more ways you can live a healthier life, see here for The Secret Exercise Tricks for Keeping Your Weight Down for Good.

John Anderer
John Anderer is a writer who specializes in science, health, and lifestyle topics. Read more about John