Sleep

Why a dark bedroom helps you sleep and recover better

Even modest light at night can disrupt sleep and the body's clock — darkening your bedroom is one of the simplest recovery upgrades.

Light is the strongest signal the body uses to set its internal clock. In the evening, falling light levels allow the brain to release melatonin, a hormone that helps prepare the body for sleep. Bright or even moderate light at night can delay and suppress melatonin, shift the timing of the body clock and make it harder to fall asleep. Laboratory studies have shown that sleeping with a moderate amount of room light can raise nighttime heart rate and affect how the body handles blood sugar the next morning, even when people do not consciously wake up.

Common sources of bedroom light include streetlights through thin curtains, standby lights on electronics, phone screens and lights left on in hallways. The good news is that these are usually easy to fix. Blackout curtains or blinds, covering small LEDs with tape, keeping phones face down or outside the bedroom and using a comfortable eye mask can bring light levels close to darkness. If you need light during the night, for example to go to the bathroom, a dim, warm-colored night light placed low is less disruptive than overhead lighting.

A dark room works best as part of a broader sleep routine. Keeping the bedroom cool, quiet and used mainly for sleep, dimming lights in the hour before bed and getting bright light exposure during the day all help the body clock stay on track. For people who train hard, better sleep quality supports recovery, mood, appetite control and performance. If you still sleep poorly despite a dark, comfortable room and regular habits, it is worth discussing it with a doctor.

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