“Knock, knock.” “Who’s there?” “Spell.” “Spell who?” “W…H…O!” Have you ever heard a corny joke similar to the one above and groaned in mock misery? You probably then made light fun of the person who told it, and even laughed at them and at the joke itself. Did you know that by doing so you just improved your health?

The average adult laughs 17 times a day. Multiple studies have shown that this complex action has many benefits to one’s emotional and physical health.

But what is laughter? It is the physiological response that humans have to humor. During a laugh, 15 facial muscles contract and the respiratory system becomes upset by irregular breathing, which can cause gasping. Sometimes, tears flow and faces turn red. Meanwhile, strange and unique sounds, ranging from giggles to guffaws, are heard.

What are the results of this bizarre set of reactions that we all enjoy so much? Consider. Have you ever expressed a sigh of contentment after a good laugh with some friends? That satisfaction is a direct by-product of our bodies shutting down the flow of certain hormones produced when we feel stress or anger. These hormones suppress our immune systems. Therefore, by shutting off their flow, we experience a sense of relaxation and a boost to our immune system.

Also, during laughter, our bodies increase production of various immune system cells that help us destroy tumors and viruses, fight diseases, and respond faster to sickness.

What is another benefit of laughing? How about a total body workout?

Researchers estimate that laughing 100 times is equivalent to spending 15 minutes on an exercise bike. That is why you may feel worn out after a giggling spell. You just exercised your stomach, back, respiratory and facial muscles—and possibly even your leg muscles, depending on how hard you laughed!

So, maybe you do not think of yourself as much of a “laugher.” Or, maybe you are asking yourself, “How do I learn to laugh more?” Use the following tips to increase the “giggle-factor” in your life—and improve your overall health at the same time!

Surround yourself with happy, funny people.

Watch funny movies with friends.

Learn some jokes—then tell them!