The vertical leg crunch exercise is one that is sometimes overlooked by a lot of bodybuilders, both professional and amateur. You should take a look at it because it is quite effective especially for your obliques and rectus abdominis. Here is what you will need to do:
- Lie with the face up on the floor and start lifting the legs up while keeping your knees crossed.
- Contract the abs muscles and lift your shoulder blades. The chest should try and reach the feet.
- Keep the legs fixed and then after reaching the top position lower the legs but only after doing the crunches.
You should do around 2 to 4 sets, each with 10 to 20 repetitions. This should be enough and will work pretty well on your 6 pack abs. A demo video of vertical leg crunches can be seen after the jump.