Rock | Hard

According to the ACE Fitness guide on core training , developing rock-hard abs requires targeting all four major abdominal muscle groups and incorporating back stabilizers.

To help you get exactly what you need, direct overviews for both interpretations are provided below. Rock Hard

If you are looking to build solid muscle, incinerate body fat, or carve out a strong core, true results come from a combination of structured resistance training and strict nutrition. According to the ACE Fitness guide on core

Is There a Quick Fix to Getting Rock-Hard Abs? - Genesis Health Clubs incinerate body fat