One-Arm High-Pulley Cable Side Bends

How to do it

Connect a standard handle to a tower. Move cable to highest pulley position.
Stand with side to cable. With one hand, reach up and grab handle with underhand grip.
Pull down cable until elbow touches your side and the handle is by your shoulder.
Position feet hip-width apart. Place free hand on hip to help gauge pivot point.
Keep arm in static position. Contract oblique to bring the weight down in a side crunch.
Once you reach maximum contraction, slowly release the weight to the starting position. The weight stack should never be unloaded in a resting position. The aim is constant tension during the set.
Repeat to failure.
Then, reposition and repeat the same series of movements on the opposite side.

What muscles does the One-Arm High-Pulley Cable Side Bends work?: Mainly the abs.
What equipment do I need?: Cable.
Is it good for beginners?: Yes, it is rated beginner level.
How do I track progress on it?: Log each set and beat the weight or reps from last time. Liftrung shows your last set beside the next one and estimates your one-rep max from your sets.

Exercise descriptions: free-exercise-db, public domain.