5 Minute Plank Abs Challenge – 1.1.6

The plank is one of the best exercises you can do for your core because it builds isometric strength to help sculpt your waistline and improve your posture. And depending on the type of plank you try, you can also engage your back, arms, shoulders, glutes, and hamstrings. Win! Free app, train at home. No gym equipment required! Features.