We mostly all agree that hot tubs, massages and the like feel good, but ask anyone why and you’ll get a shrug (which is fair! That person was trying to relax, after all). Understanding what these self-care activities are doing to your body — and more importantly, why they feel so good — can actually help you reach peak relaxation, though. That’s why we’re looking at the science behind various feel-good pursuits. Today’s focus: Taking a steamy shower.
There are several reasons why a hot shower feels good, many of which are purely physical. For starters, the heat reduces soreness. “The heat warms up your muscles and makes you more pliable,” says dermatologist Anthony Rossi. “Your muscles are relaxed, and you’re not as tense.” That’s because hot water widens your blood vessels and increases blood flow, which helps transport soreness-inducing lactic acid away from tired muscles. Likewise, the water massaging your skin can improve circulation, which has a similar effect. Moreover, hot water stimulates certain nerve endings, which can help block over-animated pain signals. Hot water also works as a decongestant, helping clear you out if you’re feeling stuffed up.
On the more mental end of the spectrum, heat is just plain reassuring — one study shows that taking hot baths on a regular basis can significantly reduces symptoms of depression and loneliness. This might have something to do with hot water being able to activate the parasympathetic nervous system (sometimes called the rest and digest system), slowing your heart rate, increasing your intestinal activity and relaxing your sphincter muscles. Nothing says carefree like a relaxed sphincter!
“There’s a massive connection between sleep and temperature. In fact, our bodies naturally drop in temperature right before we fall asleep and reach its lowest temperature when we’re in our deepest stage of sleep. That’s why sleep researchers suggest taking a warm bath before hitting the hay — when you get out of the bath, your body temperature will drop, mimicking the natural temperature decrease that occurs before we fall asleep and promoting sleepiness.”
Rossi also theorises that the hot water can help the body maintain its equilibrium. “It puts your body at a more thermoregulative temperature,” he suggests. “We’re 98.6 degrees Fahrenheit, and temperatures that are closer to our body temperature are probably easier for us. We really want to maintain our homeostasis.”
Sure, being outside in 98.6 degrees Fahrenheit is uncomfortable, but since water has a uniquely high heat capacity, it allows heat to escape your body much quicker than the outside air, which means water generally feels cooler. One commenter explains this on the r/AskScience subreddit:
“The reason is all about heat transfer: water is good at it, and air is not. 90 degree air is very poor at transferring enough heat to keep your body at 98.6 degrees. Water, however, is VERY good at transferring heat. So, when you shower in 90 degree water, you’re effectively keeping the surface temperature of your skin at very close to the temperature of the water. In air, to contrast, your skin temperature must be actively regulated by perspiration. So, hot water keeps your skin at the right temperature without your body doing anything, which is ultimately what your body wants.”
There are also several other psychological reasons why hot showers feel good: They provide some much-needed privacy away from the chaos of daily life; running water serves as white noise to help clear your mind; the routine of taking a shower in general is comforting, and so on. Similarly, according to psychoanalyst Claudia Luiz: “Cleaning up of any kind, including making your bed, has been revealed to increase happiness. Simply by doing something positive, you set yourself in motion to feel better and do better.” Hence the phrase, cleanliness is next to godliness.
So go ahead and take that shower, man. You, your parasympathetic nervous system and that tight sphincter deserve it.