Stretching is a massively underrated and often ignored part of sport and exercise. The majority of people who aren't competing at a high level where there is a structured pre-match/competition taken by a coach or trainer will often ignore warming up and go straight into physical activity. I know this first hand of failing to prepare properly and suffering the consequences from that. A 10 minute warm up is better than a 3 month recovery period. It is something I will always try and avoid!
Stretching has numerous effects on preparing the body for physical activity, maintaining the optimum physical condition of the body in terms of performance and injury prevention and stretching has a big role in aiding the recovery of the body after physical activity.
Stretching helps avoid muscular tightness and imbalances. Tight muscles often effect how we move and our posture, if we have a tight muscle it can lead to an imbalance in function between certain muscles placing added undue stress on the opposing muscles and joints which overcompensate and sacrifice optimal movement patterns/sequences to complete the task. These imbalances increase the risk of injury massively, especially in activities where large forces go through the joints e.g. running/jumping/throwing. Stretching will also aid speed, strength and power in performance terms through reducing reciprocal inhibition (the reduction of nerve signals due to tight muscles). Correct posture, movement and function are taken for granted unless you are aware of how we should move and function correctly.
Stretching allows for an increased range of motion (ROM) this means that for someone who has a good ROM they can recruit more muscles and therefore produce a larger amount of force in that action. An example of this is a running stride, if someone has limited hip mobility their stride length will be smaller and they won't be able to recruit as many muscles in that stride, reducing their power, speed and ultimately performance. Stretching has also been shown to increase muscular growth through increasing range of motion because it will be stimulating more muscles to grow, also by increasing the elasticity of the muscle fascia which further allows the muscles grow.
There are many different ways of stretching and there has been lots of research and critical reviews into some of these methods.
Firstly I will talk about static stretching which is the simplest and most renown method of stretching. Static stretching involves holding a stationary position whereby a select muscle group is stretched in an extended position. Typically people are told to hold these stretches for 8-10 seconds. Now, the main problem I have with this method is generally for a warm up light cardio is used first to increase heart rate, blood flow, muscle and core temperature ready for exercise and then to go into a static stretching regime the body will cool back down negating the benefits of the initial warm up. Static stretching has also come under some scrutiny with its effectiveness in injury prevention, its effectiveness in increasing range of motion and improving flexibility. To make the most of static stretching it would be to use it as a cool down method but the time of hold should be 45+ seconds rather than 8-10 this will allow the muscle to return to its original length (as muscles tighten during exercise), it aids the delivery of fresh blood and nutrients to the muscles and simultaneously removes the free radicals and waste products caused through the muscular contractions.
The next method of stretching I will talk about is dynamic stretching. This method is becoming the most preferred method of stretching for "warming up" and I am one of those trainers behind the method. Unlike static stretching, dynamic stretching involves performing movement patterns that will be replicated in the subsequent sport/exercise, gently and progressively increase the ROM around those joints rather than stationary holds. The main advantage of dynamic stretching is that the body is still moving whilst performing these stretches and as a result it maintains the acute physiological adaptations from the warm up beneficial for performance/injury prevention.
One of the main factors to take into account when conducting a dynamic stretch is that the stretch doesn't become an exercise, what I mean by this is that movements like sumo squats and lunges are good dynamic stretches but if used too soon in the warm up or if too many are performed it becomes an exercise set rather than a stretch, placing a greater demand on the muscles than desired at this point. It is important to take each movement slightly further than the previous as the muscles become in tune to the movement pattern and the increased blood flow, neural feedback, muscle temperature and elasticity will enable you to increase the stretch and making the most of the method. Dynamic stretching will also better prepare the joints for exercise than static stretching by increasing synovial fluid secretion which will effectively lubricate the joints and allow for better movement and avoid pain.
The final two methods of stretching I will talk about are essentially static stretches but use muscular contractions during the stretch to enhance the effectiveness of the stretch.
Proprioceptive Neuromuscular Facilitation (PNF) stretching is a method of stretching that dramatically increases ROM in a very short period of time. PNF involves the athlete/patient/client being placed in a gentle position of stretch where they can feel the stretch but is not in pain, relaxed and breathing normally. They will hold this position for 25-30 seconds then instructed to take a deep breath and sub-maximally contract (20-50% max effort) the muscle being stretched in an isometric contraction (joint angle remains the same) holding this contraction for 8-10 seconds then exhaling and relaxing. Once this is performed the stretch will be able to be increased and be repeated two more times to get full ROM from that muscle.
Muscle Energy Technique (MET) as it is known to sports massage therapists is essentially the reverse process of PNF whereby the athlete/patient/client is positioned in a light stretch before the pain barrier and contracts sub-maximally for 20-25 seconds then deeply inhales and exhales whilst relaxing the muscle as it then is put into an increased stretch before repeating the process 2-3 more times. So PNF is relax-contract-relax repeat, MET is contract-relax-contract repeat.
How does this work? Well we all have a safety mechanism in our muscles called golgi tendon organs (GTO's) which detect the rate and length that our muscles contract and relax. Imagine them as a coil spring when lengthened and stretched they send feedback to the brain to contract and restrict any further movement preventing the muscle from damage. However, during PNF stretching the isometric contraction essentially tricks the GTO's into thinking the muscle length has shortened, preventing the brain from protecting the muscles by shutting down the movement, allowing the muscle to be stretched further and increasing the ROM.
These two methods are very effective, personally I prefer the PNF relax-contract-relax method as I tend to find clients responding better to it and I feel it gives me as a trainer a better indication to tightness asymmetrically. These can be used in a warm up as they provide much better results compared to traditional static stretching. However, they do possess the same issue as static stretching where the body is stationary and will cool down, so if they are implemented in a warm up then the athletes/patients/clients must be re-warmed again prior to the sport/activity/exercise to gain the most benefits from the stretches.
Stretching is also complemented well by massage therapy and foam rolling. This is especially relevant when relieving areas of tightness where adhesions develop between different muscles. It becomes hard for the adhesions to be broken up and remedied through stretching alone, the additional help will support muscle function and good ROM.
I hope this article has been of some help, if anyone would like to know more about the topics in this article feel free to get in touch.