Requires the athlete to hold a strong isometric unsupported position for the given time. This is extremely useful for building usable core strength. The core is designed to work in a isometric position so we make it strong in this position.

Training:
2 minutes jump rope
2 minutes sit-ups
2 minutes plank
90 seconds jump rope
90 seconds sit-ups
90 seconds plank
60 seconds jump rope
60 seconds sit-ups
60 seconds plank
30 seconds jump rope
30 seconds sit-ups
30 seconds plank



Decent video of the plank