Stretching can be an overlooked component of a fitness program but it offers extended benefits.
The efficacy of stretching in an exercise regime is a long-debated subject. Is it a time-waster or a valuable investment in the future health of your body?
Stretching forms a basic component of most people’s exercise regimes so it is important to question what you are actually trying to achieve with a stretching program. The aim should be to increase the length of the muscle to allow for an adequate range of motion of your joints. However, length of muscles alone is not enough and the strength of the muscle is also very important. It’s no good being able to do the splits if you are unable to stabilise the knee joint in that position.
There are two basic reasons for considering a stretching program: muscle rehabilitation post injury; and chronic stretching to increase Range of Motion (ROM)
When stretching for rehabilitation, ensure that the injured muscle is first able to recover from the initial injury. This is dependent on the injury but generally will take five days or so before the muscle integrity has repaired enough to allow for any benefit of stretching. Prior to this, the actin and myosin filaments (the building blocks of muscle tissue, or sarcomeres) are not reformed sufficiently to be able to cope with stretching without causing more damage.
Post-injury you will experience a decreased ROM, decreased strength, as well as scarring. All of this adds up to a greater risk of re-injury. The focus of a good rehabilitation program is to lengthen the muscle as well as strengthen the muscle in this new range to allow for optimal function.
Chronic stretching can lengthen a muscle in two different ways: it increases the number of sarcomeres and it increases the length of the sarcomere.
Which of these mechanisms plays the most important role in increasing the length of a muscle over time is debatable. Based on current research both appear to play a role.
You can think of a sarcomere as a stretchy rubbery ‘brick’ in a muscle ‘wall’ (the scientific term being viscoelastic). We can make our wall of muscle longer by putting in more bricks or by lengthening the current bricks. The problem which this causes is that as we lengthen by either process it affects the structural integrity of the wall so the new bricks and/or longer bricks require strength training to be able to create as much force as the same muscle did before within its previous ROM. This may sound disheartening at first but the effects of chronic stretching can take weeks to months to show, so the changes in the structural integrity of the muscle are constantly adapting to this new length.
The lesson is two-fold. First, if you are undertaking a stretching program as part of your exercise program (and you should be) remember that it takes a long time to increase the length of a muscle. Second, make sure you continue to strengthen the muscle as it lengthens, particularly in the case of a recently injured muscle.