Can laughing give you a workout?

(CNN) -- Rolling on the floor laughing, giggling until your stomach hurts, guffawing and slapping your knees -- sometimes laughing can feel like a workout.

Studies have shown that mirthful laughter, the kind that stems from real joy, relieves stress, lightens mood and confers health benefits.

Since the concept of laughing for health surfaced in the 1970s, studies have indicated it can decrease cortisol and epinephrine (the hormones that regulate stress), help reduce blood vessel constriction and boost immune function.