Training the abdominal muscle group is no easy task. The muscles do not all respond to training at the same rate and there is a core group of abdominal s, running beneath the external ones with muscle fibres pointing the opposite way. This makes for a core picture which no single exercise can adequately address which helps explain why strong abs are hard to attain, which makes them an aim to strive for. The plank helps develop strength in the core, shoulders, arms, and glutes. The longer you can