Sat Bir Khalsa, a Harvard Medical School sleep researcher and Kundalini yogi, has found that people who do intentional breathing and meditation before bed experience sounder sleep than those who don’t. He recommends the shabad kriya: Sit upright with your right hand resting palm-up in your left hand, thumbs touching. Inhale in four short bursts in time with the silent mantra Sa ta ma ma. Hold for a few moments and then exhale in two segments, silently repeating Wahe guru. Repeat and continue for 10 minutes.