This exercise strengthens the core.
1 Begin on your stomach on your elbows and toes (or knees).
2 Lift your trunk up off the surface to form a straight line keeping your abdominal muscles tight.
3 Be careful not to lift the gluts up higher than your back.
4 Hold for 10 seconds and repeat 10 times.
Once you've finished the exercise, click to see what percentage you have completed.