Bruce Lee was a martial arts icon of our time, boasting one of the strongest bodies ever seen. He always focused on possessing a powerful body to be able to take the demands of martial arts, or pretty much any activity. He saw the abdominal musculature as a shield that protects the rest of the torso. And wouldn’t you know it – he boasted one of the most chiseled physiques ever known.

Lee always stressed perfect form when exercising. Regarding sit-ups, he’d once said, “The proper way of doing sit-ups isn’t just to go up and down, but to curl yourself up; to curl yourself back up, like rolling up a roll of paper.” He’s absolutely right. Form is of utmost importance, and if your form isn’t sound, why even exercise?

So without further ado, here is Bruce Lee’s Abdominal Workout (and in addition to these, please check out these easy tips on toning your stomach):

1. Sit-up twists.

4 sets of 20. Lie on the floor or a mat, with your knees bent and toes directed ahead of you. Try to minimize as much space as you possibly can between your lower back and the mat. Rest your hands behind your head, but you don’t have to interlock your fingers. Curl up gently like the newspaper Bruce Lee talked about as far as you can go comfortably. Turn your torso to the left as far as you can go comfortably. Smoothly come back to your beginning position. Repeat the exercise and twist your torso to the right this time. This is one repetition.

2. Leaning twists.

4 sets of 50. Stand up straight and place your feet about 2 ft apart. Take a broom handle or wooden pole and place it on your shoulders. Grasp it with your hands wherever you can comfortably. Bend your upper body forward while keeping your back straightened, and then turn the pole up toward the ceiling as far as you are able to comfortably. Come back to your beginning position and do the exercise again for the other side. This is one repetition.

3. Waist twists.

4 sets of 70. Sit up straight on a chair with your toes facing ahead. Put your broom handle on your shoulders and grasp it with your hands. Twist your torso slowly to the left. Hold this position momentarily and come back to the middle. Repeat the movement and turn to the right this time. This is one repetition.

4. Frog kicks.

4 sets of 50. Lie on the floor or a mat and close the gap between your lower back and the mat. Move your knees up to your sternum and kick your feet out at around 45 degrees.

5. Leg raises.

4 sets of 20. Lie on the floor or a mat, with knees down, and your legs together. Remember to close that gap between your lower back and the mat. Gently raise your legs together, upwards to around 45 degrees, and slowly return to the starting position, but don’t let your legs touch the floor.

Together with these ab exercises, Bruce Lee rode an exercise bike for about 45 minutes daily, as discussed in these easy tips on toning your stomach.