The crunch is one of the most common abdominal exercises. This calisthenic exercise is easy and effective to train you abs. Sit ups are usually performed on a flat underground, but alternative exercises as shown below are just as effecive
HOW TO DO A SIT UP
- Lie on your back with your knees bent and you feet flat on the floor.
- Place your hands on your head.
- Pull your shoulder blades back so your elbows are out to the side.
- Brace your abs and then raise your body up towards your knees. Your shoulders should be lifted of the floor.
- Roll back down to the starting position.
What is the differences between a crunch and a sit-up?
Unlike the sit-up, in a proper crunch, the lower back stays on the floor. This is said by scientific literature to eliminate any involvement by the hip flexors, and make the crunch an effective isolation exercise for the abdominals.