Bruce Lee perfected his abs through an intensive, daily routine that worked them to the max. He believed that a strong set of abdominal muscles changed all the power the body could output in every movement and it appears, he was right. 

Instructions: Repeat each move 10, 20, 30 or 40 reps depending on your fitness level with no rest in between until the set is done, rest up to 2 minutes and repeat the whole set again, 3 times in total.

What it works: upper abs, lateral abs, lower abs, core, quads.

Tips: Bruce Lee was renowned for his explosive martial arts moves. Aim, here, to do every exercise as fast as you can, upping your personal intensity level, exhaling fast and hard at the point of maximum muscle tension.