The bench crunch is a popular ab exercise performed lying on a bench. It is largely similar to the same exercise performed on the floor, but being able to press the lower back into the bench pad can help reinforce proper form and increase the burn in the abs. Like most crunch variations, it is usually performed for moderate to high reps, such as 8-12 reps per set or more.
Benefits
Focuses on the rectus abdominis or "six-pack" muscles, particularly the upper abs
Easy to learn and master
The balance challenge of staying on the bench may make the core muscles work harder
