What is a curl-up?

Self-tutoring about exercise: the tutor seeks the definition of curl-up.

A curl-up is done like so:

1. The arms are folded across the chest.
2. The heels are flat on the floor.
3. The knees are bent.
4. In the “down” position, the person’s shoulder blades touch the floor.
5. In the “up” position, the elbows touch the knees.

Source:

www.military.com