Exercise will help improve the quality of your sleep—if you time it right. Working out late in the day can actually leave you staring at the ceiling in bed, since it can take three to four hours for your body to cool itself afterward. "When your core body temperature is too high and your heart rate is too fast, it can keep you awake," Ojile says. It's better to exercise at least four hours before bedtime. Better yet, hit the gym in the morning or at lunch—you'll feel the energy-boosting effects for hours.