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.

Core strength testing has come a long way from the straight-legged, twisting sit-ups used before World War II. We've moved on to bent-knee sit-ups, to crunches and now to the plank pose or hanging ...

Core muscles wrap around the midsection like a girdle, forming a connecting link between the upper and lower body. They support, stabilize, and help move your spine, trunk, and pelvis, and most body ...