Not just for the ladies, kegels strengthen the pubococcygeus or "PC" muscle, and are easy to do. "The exercise itself couldn't be simpler," says Hays. "Contract the PC muscle, the same one that you'd use to stop the flow of urine in midstream. Squeeze and hold for three to five seconds, then relax." Kegels improve ejaculatory control and can lead to stronger, firmer erections. Plus, they can be done pretty much anytime, anywhere. Hays suggests doing one set of 10, three times a day.