Lie on the floor with your legs straight up in the air or as high as they can go while your back remains flat on the ground. Your hands should be behind your head with your elbows out wide.
Lift your shoulders off of the ground and pull your belly button into your spine to engage your core.
As you lower your left leg to the ground, twist your torso to the opposite side, leading with your left elbow. Bring your left leg back up to meet your right, and return your upper body to center.
Switch sides, lowering your right leg to the ground and twisting your torso over to your left leg with your right elbow leading, before bringing your right leg back up and returning to center.
One crunch on the right and one crunch on the left equals two reps.
Alternate sides for a total of 30 reps, and rest for the remainder of the minute.