Dez Bryant -- Can You Stomach My Insane Ab Workout?

Welcome to "Dez Bryant Is a Freak of an Athlete: Part 46" ... this time, it's all about his insane ab workout.

Here's video of the Dallas Cowboys star using his legs grip a heavy bag ... and then doing several sets of FULL EXTENSION sit ups while hanging from the top.

Yeah, this ain't exactly the B.S. halfway crunch things most people do in the gym.