Callenetics exercises use movements as delicate as a pulse. There are no jerking or bouncing movements. Callanetics is and always has been no-impact. It is not difficult to do, but you WILL feel your muscles working, as these tiny movements are in fact incredibly powerful, providing an extremely fast, safe and effective way of achieving a strong and flexible body. Callanetics exercises tighten and reshape the whole body, while increasing flexibility, strength and body alignment.