1. Begin lying on your back with your legs lifted off the floor slightly and your arms by your sides.
2. Bring your knees in to your chest, then straight up towards the ceiling, and crunch upwards taking your hands towards your shins.
3. Reverse the movement to return to the start, lowering your upper body back to the floor and bending your knees to your chest, then extending them straight out just above the floor.
Aim to complete three sets of 10-12 reps.
Keep your lower back pressed into the floor throughout the exercise. If you feel your lower back arching, lift your legs higher off the floor when extending them.
1. Place the front of your hips on the top of a swiss ball, with your feet on the floor. Place your fingertips against your temples and lower your upper body over the ball – this is your starting position.
2. Raise your upper body to form a straight line between your head and feet. Hold this position for a count of one then slowly return to the start and repeat.
Aim to complete three sets of 15-20 repetitions.
Performing this exercise on the Swiss ball gives you a larger range of motion than when doing the regular extension on the floor.
If you can comfortably perform 20 reps, hold a weight with both hands across your chest to increase the difficulty.