The bench oblique crunch is an exercise that targets the obliques, the muscles running alongside the rectus abdominis. The range of motion is fairly small, but it still does a great job of working these hard-to-isolate muscles. Like most crunch variations, it is usually performed for moderate to high reps, such as 8-12 reps per set or more.
Works the obliques
Easy to learn and master
The balance challenge of staying on the bench may make the core muscles work harder