FC2-PPV-4655177 This time, you'll get to see An's dedicated efforts. As some of you may already know, this is an exercise using vaginal training balls. These egg-shaped training balls are inserted after applying Vaseline or lubricant. The key aspect of this workout is tightening your pelvic muscles to keep the ball from falling out. There are three different sizes available, each offering varying levels of difficulty for added enjoyment.