The term ‘dynamic stretches’ refers to stretching exercises that are performed with movement. In other words, the individual uses a swinging or bouncing motion to extend their range of movement and flexibility. Listed below are four different types of dynamic stretching exercises.
1. Ballistic Stretching Ballistic stretching is an outdated form of stretching that uses momentum generated by rapid swinging, bouncing, and rebounding movements to force a body part past its normal range of movement. The risks associated with ballistic stretching far outweigh the gains, especially when better gains can be achieved by using other forms like dynamic and PNF stretching. Other than potential injury, the main disadvantage of ballistic stretching is that it fails to allow the stretched muscles time to adapt to the stretched position and, instead, may cause the muscles to tighten up by repeatedly triggering the stretch (or myotatic) reflex.
2. Dynamic Stretching Unlike ballistic stretching, dynamic stretching uses a controlled, soft bounce or swinging motion to move a particular body part to the limit of its range of movement. The force of the bounce or swing is gradually increased but should never become radical or uncontrolled. Do not confuse dynamic stretching with ballistic stretching. Dynamic stretching is slow, gentle, and very purposeful. At no time during dynamic stretching should a body part be forced past the joint’s normal range of movement. Ballistic stretching, on the other hand, is much more aggressive and its very purpose is to force the body part beyond the limit of its normal range of movement.
3. Active Isolated Stretching Active isolated (AI) stretching is a new form of stretching developed by Aaron L. Mattes and is sometimes referred to as the ‘Mattes Method’. It works by contracting the antagonists, or opposing muscle group, which forces the stretched muscle group to relax. The procedure for performing AI stretching is as follows.
1.Choose the muscle group to be stretched and then assume the appropriate starting position.
2.Actively contract the antagonists, or opposing muscle group.
3.Move into the stretch quickly and smoothly.
4.Hold for 1–2 seconds and then release the stretch.
5.Repeat 5–10 times.
While AI stretching certainly has some benefits (mainly for the professional or well-conditioned athlete), it also has a lot of unsubstantiated claims. One such claim is that AI stretching does not engage the stretch reflex, because the stretch is only held for 2 seconds or less. This, however, defies basic muscle physiology. The stretch reflex in the calf muscle, for example, is triggered within three-hundredths of a second, so any claim that AI stretching can somehow bypass or outsmart the stretch reflex is nothing more than wishful thinking.
4. Resistance Stretching and Loaded Stretching Resistance stretching and loaded stretching are forms of dynamic stretching that both contract and lengthen a muscle at the same time. They work by stretching a muscle group through its entire range of motion while under contraction. For this reason, both resistance stretching and loaded stretching are as much about strengthening a muscle group as they are about stretching it. Like AI stretching above, resistance stretching and loaded stretching do have their benefits. The five-time Olympic swimmer Dara Torres credits a portion of her swimming success to the use of resistance stretching. However, these forms of stretching place high demands on the musculoskeletal system and therefore are recommended only for professional or well-conditioned athletes.