Curl ups ("Crunch" Core/abdominal strengthening, arms crossed; 01)

Lie on your back with your knees bent and your arms crossed over your chest with your lumbar spine pressed towards the floor.
Breathe in, and then exhale as you lift your shoulders off the floor.
Keep your abdominal muscles tight as you curl up off the floor and do not allow your lumbar spine to raise off the mat.
Return back down to the starting position in a slow controlled manner and repeat.