Do the different settings on the decline bench work different areas of the abs, or what is their purpose?

Answer 1

Actually, doing your ab work on a decline is probably one of the toughest ab workouts you can do.

The higher the decline, the more muscle it takes to get crunch your abs.

Mostly, though, you are working the same ab muscles, just through a greater range of motion as well as difficulty.

The decline bench can be used for a variety of exercises, including bench presses and shoulder work. It is up to you on what angle you'd like to set the bench at.