Lifestyle

Tryptophan causes sleepiness. Proteins from the food we eat are the building blocks of tryptophan, which is why the best bedtime snack is one that contains both a carbohydrate and protein such as cereal with milk.

Melatonin helps control your sleep-wake cycles. Your body’s internal clock (also known as your circadian rhythm) influences how much melatonin your body makes, as does the amount of light that you're exposed to each day.

Sex = good for sleep. It boosts oxytocin (a hormone that makes you feel connected to your partner) and lowers cortisol (a stress-related hormone). Plus, orgasms release prolactin, which help you feel relaxed and sleepy.

Generally, caffeine lasts for 5 to 6 hours in the body before wearing off. So cut out the coffee after early afternoon so that you can start to wind down in time for bedtime.

Sleep improves your ability to make more accurate split-second decisions by about four percent. Hey, it may not sound like much, but every little bit helps!

It doesn't matter when you hit the gym, just that you get in your daily burn. People who work out regularly sleep better—and longer—than those who don't.