This movement is performed on a standard cable machine with the use of a single D-handle. This is one of the best exercises to target the obliques in a very unique way.
Begin by standing with your side to the machine.
Grab the D-handle and pull it down so your arm is locked straight down to the side.
From here perform the same movement as you would a dumbbell side bend. The difference with this is the resistance is now opposite what it would be with a dumbbell. The tension is now on the downward phase.
Tighten your abs and obliques. Now bend to the side and make sure to keep a controlled tempo. Flex your obliques very hard when you reach the midpoint and keep your upper body erect.
Return to the start position slowly while keeping as much tension on the obliques as you can.
When you complete the set you'll then switch sides. I've found this movement works very well when performed two ways. The first way is to train very heavy for 6-8 reps. Another method that works very well is to keep the weight light for sets in the 30-60 second range.
Training Mistakes
Going too heavy. This may cause you to break form and begin to bend forward.
Going too fast. Keep the tempo slow and controlled, making sure to keep tension on the muscle.