Exercise, but not within 4 hours of bedtime

Working out—especially cardio—improves the length and quality of your sleep, says Dr. Shives. That said, 30 minutes of vigorous aerobic exercise keeps your body temperature elevated for about 4 hours, inhibiting sleep. When your body begins to cool down, however, it signals your brain to release sleep-inducing melatonin, so then you'll get drowsy.