The Double Crunch is a great abdominal exercise because it emphasises both the lower and upper portions of the stomach at the same time.
1. Lie on the floor. Hold the kettlebell with both hands round the ball and the handle resting near your collarbone, your elbows should be tucked into your side. Your shoulders should be positioned back and down with your abdominals tense. The legs should be flat out.
2. Press the kettlebell upwards in a straight line above the chest extending the arms, and generating the power through the chest, shoulders and arms.
3. Keeping a slight bend in the elbow bring the kettlebell over your head extending the arms out. Before the kettlebell handle touches the floor, tighten up the lats and begin to bring the kettlebell back over your head. (See Fig. 1)
4. Aim to curl your spine from the floor whilst bringing the kettlebell back over head. At the same time bring your legs to a 90 degree angle. Your knees should finish directly above your hips, and your ankles should remain in line with your knees throughout the movement.
5. As you crunch extend the arms and reach the kettlebell over the front of your shins. Remembering to make sure that the knees don’t travel past the hips. Keep the abdominals tense throughout. (See Fig. 2)
6. To reverse the movement extend the legs and arms trying not to let the lower back arch. You may need to be careful how far you reach overhead and how far you extend the legs. Go as far as is comfortable. Think about rolling your spine back into the floor with control using your abdominals. Do not let your legs or the kettlebell drop to the floor. Repeat the movement from point 3 for as long as desired.

Double Crunch
Fig. 1

Double Crunch
Fig. 2

Once finished return the kettlebell back to the chest decelerating through the arms and shoulders. Then lower the kettlebell back to the floor.