9 Core Exercises That Get You Closer to Six-Pack Abs - Healthy Tips World Everybody wants a six-pack—which is great. But FYI, there are actually four key muscle groups you need to tone to get a taut tummy. “For the best results, both aesthetically and functionally, you need to target all the muscles in your abdomen,” explains NYC-based trainer Joan Pagano, author of Strength Training Exercises for Women. What … http://snip.ly/qhtfb