The crunch is a classic ab exercise. It’s also pretty straightforward: Lie on your back with your knees bent and feet flat on the floor, contract your abdominals, and lift your shoulders, neck, and ...

Crunches, on the other hand ... Engage your core muscles by drawing your belly button towards your spine. Keep your shoulders ...

The main difference between sit-ups and crunches is the range of motion involved in each exercise. Sit-ups require you to lift all the way up, while crunches require a slight lift off the ground.