One of the easiest ways to strengthen the stomach muscles and build a tighter midsection is through the use of hanging ab straps. The reason ab straps are so effective is that they provide more core resistance since you’re working against gravity and pulling yourself up.
It’s carabiner and the strap to begin you’re gonna wrap it around the bar. And you’re gonna loop that carabiner. Back through the opposite side strap
Pull up Bar AB Slings Straps Sports and Fitness Equipment Hanging Straps Belt Chin Up Sit Up Bar Muscle Training Support Belt