In many cases it is relatively small movements such as the hand slide crunch exercise which have the greatest impact on your upper and lower abdominal muscles. The starting position for the hand slide crunch exercise is to lie down on the ground with your feet flat and your knees raised. Then place your hands onto your thighs and sit up only using the top half of your body. As you sit up, slide your hands down towards your knees and pause at the top of the cycle. Then lower yourself back down towards the ground. Repeating the exercise, while not touching the ground with your upper body, will stretch and develop your abdominal muscles. If you want to develop this exercise, on the down movement do not touch the floor before the next up movement and you will feel extra pull on your abs.