If you're a regular watcher of women's talk shows or the Sex and the City series and films, then you probably know what Kegels are. The exercise is named after Dr. Arnold Kegel, who invented an instrument that measured the strength of pubococcygeus, or PC, muscles. These muscles exist in the pelvic floor of both men and women, and they can weaken as a result of pregnancy, childbirth and prostate issues in men. The result of that weakening can mean urinary incontinence, stress incontinence and erectile dysfunction in men. For both men and women, strengthening the PC muscles can lead to heightened sexual enjoyment by allowing men to control the onset of ejaculation. And because this is the muscle that contracts when women have orgasms, it can increase the intensity and probability of having an orgasm.