Laughing sends chemicals called endorphins to the brain. These soothe pain and improve your sense of well-being. Laughter also stimulates the heart, lungs, and muscles; improves your resistance to infection. If you laugh for 20 seconds, the body receives the same amount of beneficial oxygen (good for stress relief) as with 3 minutes of cardio exercise. It is also almost impossible to remain tense while laughing. Look for cartoons, TV shows, writers, and comedians that make you laugh. Share jokes on social media with friends.