How important is stretching to you? Probably ranks right up there with going to the dentist or cleaning out your gutters, right? I have to admit that the idea of stretching, putting my body into uncomfortable positions and producing pain for myself is not my idea of fun. Now, how important is flexibility and preventing injury? When we think about these goals, especially as tennis players, they probably rank a little higher on the priority list – and if not, they should. I’d like to look at how important flexibility is, how to incorporate stretching into our exercise regimens, and what benefits it has to overall body fitness.
Stretching Physiology
Let’s look at what stretching actually does first. Muscles are composed of long, elastic fibers called fascicles, and like any elastic material, they work better when warm and flexible, Proper stretching takes the muscle into it’s full, extended state, aligning the individual muscle cells (called sarcomeres) and can serve to realign any cells that have become disorganized. The more fibers that are stretched, the longer the muscle becomes. The longer you hold a stretch, the more the proprioceptors (nerves that convey information to the central nervous system) allow the muscle to ‘remember’ the stretched length and become accustomed to the new length – we’ll refer to this as the ‘stretch reflex’ going forward.
Static Stretching
Our muscles have two types of intrafusal muscle fibers. The first are ‘chain’ fibers which are long and thin. When the muscle is stretched slowly, the stretch reflex nerves increase their signal rate to the nervous system, telling it to contract as the muscle nears it’s preset limit. Holding of static stretches (no movement) overcomes the stretch reflex to a point and reprograms the stretch reflex threshold, increasing the range of motion that the stimulated muscle fibers can lengthen in.
Dynamic Stretching
The second type of fibers are the ‘bag’ fibers. These fibers fire rapidly when a quick muscle stretch is initiated, sending a strong contraction signal in order to protect the fibers from tearing. This stretch reflex protects our muscles from injury caused by sudden movements. This signal decreases as the rate of change in the muscle length decreases.
Because of the differing reaction of the two ‘stretch fibers’ above, both static and dynamic stretching are important to incorporate into any stretching routine, and are beneficial in increasing the length of the muscle through bot fast and slow ranges of motion.
Warm Up First
Many times, we erringly think of stretching as our warm up before physical activity. Consider this – would you take long piece of taffy out of the freezer and attempt to pull it? It would probably break due to the inflexibility of the fibers in the taffy, right? The same is true in muscles. When we attempt to stretch a ‘cold’ muscle, we are placing demands on that group of fibers that they are not prepared to handle yet. A simple increase of a few degrees and some increased blood flow will go a long way to maximizing the stretch potential and decrease the likelihood of an injury. Running in place for a few minutes, jumping rope, or riding a bike at low exertion will accomplish the needed ‘loosening up’ of the muscle fibers that will adequately prepare them for the stress of the stretching to come.
Stretching Benefits
So, what do we hope to gain by stretching properly? Stretching can do a number of things, it increases flexibility as we just learned. It improves the range of motion of our joints by stimulating the nerve receptors located near the end of the muscle fibers. It improves circulation, increasing the flow of blood into the muscles, which increases performance and can speed recovery. Stretching can also decrease stress by causing the surrounding muscles to lengthen and then relax in a uniform manner.
We didn’t discuss any particular stretches in detail because there are a multitude of resources out there and if we keep in mind what our body actually does when it stretches, we can use some common sense to find the right ones for us. We all know how important flexibility is as a tennis player, and hopefully you’ll give it some more thought now that you know what it’s all about.
