Abs with a emphasis on the upper abs.
Best In Workout:
In general, always do abs last in your workout, following your major bodyparts. But within your ab-specific training, put this weighted crunch before your bodyweight moves.
Sets & Reps:
Perform 4 sets with 10-15 reps
Place a decline bench near a low pulley (your head nearest the stack). Most gym have portable abdominal benches, so drag or carry one to the pulley station. Place it a couple of feet away from the stack so that when your grasp and place the rope in place, the weight rises off the stack and will not touch down between reps.
Hook a rope attachment to the cable and hold the handles tight to your body outside your ears. You can also grasp both ends of the rope and hold them on one side of your head. The emphasis is not altered all that much and could be more comfortable and practical depending on the attachment. But if your do so, be sure to transfer your hands to each side of your head from set to set.
Range Of Motion:
Crunch up as high as possible, bringing your elbow toward your quads. Because you are holding a cable that provides constant tension, you can raise your body as high as possible. In other words, you do not have to stop short of perpendicular to the floor as you do during your bodyweight version to keep the abs engaged and stimulated, but come up as high as you can go. Try not to pull through your quads to lessen the engagement of the hip flexors.
Back To Start:
Squeeze your abs hard and then slowly lower yourself to the start position and repeat. Feel free to come all the way down until your head touches the bench, but if you want to make it more difficult, stop just short of letting your shoulder blades touch the bench. Either way, do not let the weight plates touch down at the bottom of each rep.