Morning Sunlight May Be the Easiest Way to Reset Your Body Clock

Exposure to natural light early in the morning may help reset the body’s circadian clock, improve night-time sleep, boost daytime alertness, and even lift mood, according to research discussed in a Walla Health interview with Prof. Rivi Tauman on sleep disorders. The article says the habit costs nothing, needs no equipment, and can take less than 10 minutes, yet many people miss it because they start the day indoors, checking phones, making coffee, and heading to work without sunlight.

The body’s internal clock regulates sleep and wakefulness, hormone release, body temperature, metabolism, and appetite. Morning light reaching the eyes activates special retinal cells that signal the brain’s control center, suppressing melatonin, the sleep hormone, and setting up the body to stay alert during the day. That same morning signal helps shift melatonin production toward evening, which is why early light can improve sleep later at night.

The article says even a short walk outside, sitting on a balcony, or drinking coffee by an open window can be enough. Bright skies provide stronger light, but even cloudy daylight is far more powerful than indoor lighting. Studies cited in the piece found that people exposed to natural light earlier in the day tend to fall asleep faster, sleep better, feel more alert, and in some cases report less fatigue and better mood.

The effect is not limited to sleep. Circadian disruption, such as from shift work, sleep deprivation, or spending most of the day away from daylight, can raise the long-term risk of metabolic and cardiovascular problems. Screens do not replace sunlight as a morning cue, so experts recommend not starting the day on the phone but going outside for a few minutes, or at least opening a window or sitting in the sunlit balcony. The article warns not to stare directly at the sun and says people with significant or ongoing sleep problems should seek medical evaluation rather than rely only on habit changes.