Why Stretch? What Happens with Stretching?

by Paula Allia PT, DHSc, MTC, OCS

It is a common practice to stretch muscles in yoga, Pilates, and during exercise routines. What is it exactly that is so important about stretching and when should stretching be done?

Muscles are made up of protein. This protein is arranged differently in different muscles throughout the body. Depending upon the muscle fiber direction, motions occur as the muscle shortens (contracts) and pulls on the tendons. The tendons attach to the bone, and it is this combination that actually creates movement.

The contractile element of a muscle is called the sarcomere. During a contraction, the proteins in these sarcomeres slide closer together to create movement. Muscles have a significant amount of sarcomeres. These sarcomeres in muscles are laid down either in series (length) or in parallel (wider cross section). Increasing the amount of sarcomeres in series provides the opportunity for elongation and stretch while increasing muscle fibers in parallel contribute to a muscle’s strength.

Stretching can be done either actively and passively depending upon why the stretch is being done. Within muscles there are nervous system components that sense muscle positioning and length tension. This information is relayed to the brain and this loop of information prepares the guts of the sarcomeres for their next move.

It has been studied and confirmed that to build strength these sarcomeres parallel to each other have to be worked (exercised) and stressed. The muscle breaks down to build up even better provided that the workout was hard enough to cause the breakdown.

Stretching causes sarcomeres to lay down in length (series). The muscle fibers have to actually stretch in order to activate and produce more sarcomeres. Thus, stretching is the stimulus to the muscle for ultimate stretching and possible new length to occur over time.

Ensuring that protein is consumed as well as water is very important in this transformational process. Warming up by doing some form of cardiovascular activity for 5-15 minutes should be considered beforehand exercise session. This exercise stimulates the heart rate, gets the blood flowing, and Warms the muscles slightly which prepares them for exercise. Pre-exercise stretching can be done but this stretching should not be prolonged because this stretching is only done for the purposes of priming the muscles to perform. This shorter stretch can prime the neuromuscular system to be ready for contracting during exercise.

Stretching the muscle can be done in a limited range that is going to be used in the exercise session and should NOT be overdone. There is no need to overstretch a muscle into extreme lengths if those ranges are not going to be used. Priming the viscoelasticproperties of the muscle is the goal.

Immediately following your initial stretching is a good time to start strength training. If there is a long duration between the two one can lose the length rather quickly and the sarcomeres can retract back to a shorter range. Controlled movement is important which can stimulate collagen and allow for elongation. The fascia (sheaths between muscles fibers) can also lengthen. Stretching for short periods of time in the range desired can prep the muscle fibers to work better.

Post exercise session, after much of the muscle has contracted and been used, stretching for at least 30 seconds in a larger range will help stretch out the sarcomeres and fascia. Over time, the sarcomeres can elongate and retain the strength as well as the longer length.

Positioning oneself properly is key to obtaining the best stretch. After all, the muscles attach to the tendons which then attach to the ones and, if angled incorrectly, could put excess strain on the wrong structures. When stretching for relaxation and potential elongation of muscle tissue, slow prolonged stretches for 30 seconds is key. During this time work on breathing and during the exhale there is less resistance in the body so take advantage of this to allow the stretch to occur. Do not push into the stretch where it is uncomfortable. Patience is important if you desire good outcomes.

If you need help getting to a better place, please call Fitness Together at (239) 263-9348 (335 14th Avenue South) and we can guide you in the right direction.