Take it from Amy Wechsler, M.D., who recently wrote about her nightly wind-down routine on mindbodygreen: After long days working as a dermatologist and psychiatrist and grad school student, she inevitably feels stressed come bedtime from time to time.

For nights when this happens, Wechsler writes, “I learned a great pre-sleep relaxation technique from a counselor at a sleepaway camp back when I was 12 (yes, really!). She taught us to contract each muscle in our body fully, then relax it, starting at our heads and working down. This methodical tightening and relaxing always helps me, and I remember teaching it to my kids when they were younger.”

There’s some research to back up this camp folklore. One older study in the 1970s found that the progressive relaxation method was able to reduce participants’ sleep onset time 1(the time it took to fall asleep) by an impressive 22 minutes on average. More recent research on 60 healthy college students showed that the technique, when paired with deep breathing and guided imagery, was “effective in improving relaxation states2 at both the psychological and physiological level.”

The beauty of this method is that it’s easy and free to do whenever you could use some help in the sleep department. Starting at the forehead, simply contract your muscles and pull your eyebrows together, holding a tense, furrowed face for a few seconds. Then release. Focus on how relaxation feels following moments of tension. Then, gradually move down your body and repeat the process with as many muscle groups as you can. Go slow, and deepen your breath to further sink into this soothing technique.

By the end of the practice, you may note that the tension you’ve been storing in your body throughout the day has dissipated. With any luck, you’ll have released some pressure in the mind too, leaving you free to drift off to dreamland unencumbered.