Member-only story
A Simple Hack for Better Sleep
A hot bath can help you fall asleep faster and sleep better, but you need to get the timing and temperature right
Relaxing in a bath before bedtime has often helped me fall asleep, but I never knew why. I figured it had to do with, well, relaxation. The reality has more to do with tricking the body into kick-starting its natural sleep cycle by changing its temperature. New research reveals how a hot bath one or two hours before bedtime actually triggers the body to cool itself down, helping people fall asleep faster and sleep more soundly.
More than a third of Americans don’t get enough sleep, according to the U.S. Centers for Disease Control and Prevention (CDC), and this deficiency is linked to everything from bad moods to disrupted brain function and poorer health. Exercising, eating well, and avoiding alcohol and caffeine are among several ways to improve sleep without resorting to sleeping pills, which studies find can raise the odds of premature death.
But better sleep can also be achieved by leveraging the body’s natural sleep cycle, which is governed by circadian rhythms — the daily physical, mental, and behavioral changes driven by an innate biological clock located in the brain’s hypothalamus.
Getting your brain ready for bed
One significant effect of the biological clock is temperature regulation, which guides the sleep cycle. It’s all rooted in eons of 24-hour changes in light and dark. Not everyone’s biological clock ticks at the same rate, based at least in part on genetics, according to an overview from the Division of Sleep Medicine at Harvard Medical School. Differences in circadian rhythms can affect whether someone is a morning person or a night owl, and how much difficulty someone has getting to sleep at a suitable hour.
Typically, your core body temperature tends to be 2 to 3 degrees Fahrenheit warmer in the late afternoon and evening compared to when you are asleep. About an hour before your usual bedtime, your core temperature falls about 0.5 to 1 degree. Around that same time, your biological clock begins releasing the hormone melatonin into the brain, inducing drowsiness. Body temperature drops further during the middle and…
