4.) Kissing keeps facial muscles strong. Sure tight abs or cellulite-free thighs may be first on the Tone Up list, but don't underestimate the workout your mouth gets during a makeout session. Researchers say you use 30 muscles while kissing and the smooching helps keep your cheeks tight. Nice. We'll take what we can get.
5.) Kissing naturally relaxes you. Scientific reports say kissing increases the levels of oxytocin, the body's natural calming chemical and also increased endorphins, the body's feel-good chemicals. Swapping spit is also noted to increase dopamine, which aids in feelings of romantic attachment.