How to do the dragon flag. Mastering the dragon flag will make sure your abs grow big and strong. The Dragon Flag is the most advanced version of the Reverse Crunch. The dragon flag exercise helps you to build up shoulder strength and muscle mass. Dragon Flags are performed by bracing hard on a bench or hard surface, while locking your arms in a fixed position. The video above will show a progression of exercises that you can do before attempting the Dragon Flag. To learn how to do the dragon flag, watch our video below and practice the correct dragon flag progressions. DRAGON FLAG FORM VIDEO Popularized by Bruce Lee, Dragon Flags are an amazing core exercise that teaches ultimate stability. Lie on your back and reach your arms behind you to hold onto a … It also looks really cool. The legs are driven up as if you are performing a reverse crunch. The dragon flag, a move named after its supposed inventor, Bruce Lee, isn’t just a flashy exercise that got dumped into the Rocky IV training montage because it looked cool. Dragon flags also happen to be one of the hardest abdominal exercises you can do - and the benefits in strength and size correlate with the difficulty of the exercise. From there, the lifter will lower themselves down not allowing any part of their body to touch the bench except for their upper back.