Ab Twister 10-in-1 Ab Workout Machine - Abdominal Exercise Machine AbTwister abdominal exercise machine lets you select from 10 great exercises to tone and tighten 6 completely different muscle groups, all with one machine. The Ab Twister also strengthens your back muscles, helping to relieve lower back pain. AbTwister is compact and made of gym quality steel. Ab Twister is easy to take apart for storage. 10 great exercises.