For two days after I ran the half marathon, I slept so soundly for a good eight hours. The great sleep I got makes running another half marathon very tempting. But 30-minutes of any aerobic exercise should do the trick. Whenever I am extremely physical, I tend to get great sleep.
And there is research to prove it. According to a study in the journal of Sleep Medicine 20-30 minutes of aerobic exercise will help improve sleep by enabling you to fall asleep faster and stay in a deep sleep longer. One of the reasons they think this happens is that exercise raises the temperature of the body. It can stay raised for four hours, but when it cools off the temperature is usually lower than prior to exercising, which may help in falling asleep.
The benefits of better sleep are huge. The longer you are in a deep sleep the more growth hormones you produce, which helps you to rebuild and heal your body. But for me, I just love the feeling of waking up and feeling refreshed.