We run. We mountain bike. We paddle. But, do we all stretch? It’s the one training essential, like navigation, that is sorely neglected and should be considered an activity on its own – one that is incorporated into each and every training session. Just consider the benefits:
- Stretching elongates your ligaments, tendons and muscles improving your range of motion (ROM)
- Increased ROM relates to improved flexibility, decreasing your risk of injury through joint sprain and muscle strain
- Stretching incorporated into your pre-training routine assists in preparing your body for activity by bringing your physiology to a state of readiness (warming up)
- Stretching reduces muscle soreness and muscle tension, contributing to your physical and mental relaxation
Flexibility and stretching exercises fall into several categories depending on the manner in which the muscle is stretched:
- Static stretching is the safest means of enhancing flexibility by stretching to the fartherest point of muscle elongation and holding the stretch. These stretches are easy to learn, easy to execute and require little energy expenditure. But, static stretching exercises lack specificity and do little to enhance co-ordination.
- Ballistic stretching is the most controversial stretch type causing the most soreness and injury. It involves bobbing, bouncing, rebounding and rhythmic types of movement using momentum as the driving force that moves the body or limb to forcibly increase the ROM. This technique fails to provide adequate time for the tissues to adapt to the stretch.
- Dynamic stretching is often incorporated into training programs. It does not end with bouncing or jerky movements. Instead, all movements are controlled and thus enhance optimal dynamic flexibility, essential for all sports.
- Passive stretching requires you to be relaxed, making no contribution to the ROM. An external force is created by a manual or mechanical outside agent. This technique is most suitable when antagonist muscles restrict flexibility. But, there is a great risk of soreness and injury if a partner applies the external force incorrectly.
- Active stretching is accomplished by using your own muscles without the application of any external force e.g. standing upright and slowly lifting one leg as high as possible. Active stretching is preferred when the weakness of the muscles producing the movement (agonists) restrict flexibility. This form of exercise is essential to the athlete because it promotes dynamic flexibility and is the most specific to a given discipline. These stretches are easier to work into a routine as they do not require equipment or a partner.
The Cell Biology of Muscles and Stretching
A muscle is comparable to a regular electric cable.
The grey outer insulation layer is equivalent to the epimysium, an outer covering which surrounds the whole muscle mass i.e. around one of the 4 quadriceps mucles. Each of the earth, neutral and live wires correspond to mucle cells – they’re specialised cells and are thus called muscle fibres. The thin copper wires, correspond to the numerous parallel subunits within each fibre, termed myofibrils. And finally, each myofibril is made up of ‘chains’ of alternating thick and thin filaments of myosin and actin respectively, two very important contractile proteins.
I’m not going to go into the structure of these proteins except to say that they have specific structures. Actin appears like a bead necklass folded in half and slightly twised (2-stranded helix), while myosin has a structure of two pieces of rope, twised together (long thin tail) with monkey-fist knots (the head) at the top of each rope.
The Sliding-Filament Theory
Well over a century ago, researchers had observed that when a muscle contracts or stretches, the length of the muscle is altered. Using a specially built microscope, they observed that the dark bands (myosin) always stayed the same length even during contraction, while the lighter bands (actin) became narrower. the Sliding Filament Theory proposed in 1954, revolutionised the understanding of muscular physiology.
In brief, the shortening of a muscle during contraction occurs not because of a change in the length of the actin and myosin filaments themselves – and thus the myofibril – but as a consequence of the active sliding of the thin (actin) filaments between the thick (myosin) filaments. The proteins overlap.
Now, think of the actin filaments as the fluffy strip of velcro, and the myosin filaments as the other strip, the protein’s head acting like the little hooks. The more of the fluffy strip that is attached to the hook strip, the greater the tension developed. Thus, each hook provides an increment of tension, the total tension determined by the number of cross-bridges formed. Muscles with longer actin & myosin filaments can therefore develop greater tension per unit because of the greater extent of overlap possible. This explains why long muscles like your quads and hammy’s are so strong.
Now there is obviously a limit to how far you can stretch and explains the difference between you – unable to touch your toes – and contortionists.
When muscles are stretched the actin and myosin proteins reverse the action involved in contraction. At first a stretch is easy. But, as it progresses the fibres become displaced and if overstretched the muscle fibres may rupture. Thus, the importance of the connective tissue that envelops and surrounds the muscle (recall the electric cable analogy above) and its relation to flexibility.
Two nerve-fibre receptors exist (GTO’s and muscle spindles) with the ability to detect stretch at muscle-tendon and muscle-connective tissue sheath junctions. They’re responsible for the ‘Stretch Reflex’, which maintains muscle tone and prevents injury, like when you take a bad step overstretching your ankle muscles and tendons.
The most well known reflex is knee jerk caused by a light tap on the kneecap (patella) tendon. The tap stretches the muscle fibres causing them to change shape. The receptors initiate a nervous response (reflex arc) that recruits the quads causing them to shorten and your knee to straighten, taking the tension off the receptors.
Proper and regular stretching resets the point at which your stretch reflex is initiated, causing your muscles to relax further into the stretch, increasing your flexibility and range of motion during activity.
Before or After?
While it has been unanimously decided that stretching after your workout is essential, there’s always controversy over the issue whether stretching before your training session is necessary. My opinion – go for both.
When you warmup your body is prepared for activity by increasing your heart rate and rate of respiration, triggering homeostatic mechanisms like thermoregulation (induces sweating) and muscle facilitation – where muscle fibres are recruited and made ready for work.
Considering that your muscles are cold at the start of the training session, you won’t benefit much from static or passive stretching and will be more likely to injure yourself. Thus the evolution of dynamic pre-training stretches. Incorporate the following dynamic stretches into your warmup routine.
- WE ARE THE CHAMPIONS – Raise both arms above your head reaching for the sky to stretch your back. Lean over to your left and hold for 10s, lean over to your right and hold for 10s. Don’t bend forward at your hips, rather keep your posture and just lean over. You’ll feel it on your sides.
- FISH OUT OF WATER – Make as if you were swimming freestyle with one arm, swinging your arm in forward and backward circles. Do 10 circles per arm forwards and then 10 circles per arm backwards.
- “FISH OUT OF WATER: TAKE 2” – This time make circles with both arms at the same time. Do 10 circles forward and 10 circles back. Remember that the object is not to swing wildly as fast as possibl but to move your shoulder joint through its full range of motion (ROM).
- I’M AN AEROPLANE – This time work on your co-ordination. Start with your right arm up towards the sky and your left down at your sides. Bring your right arm down (forward circle) and your left arm at your side up (backwards circle). Your arms will pass each other in front of your chest. It’s like pretending that you’re an aeroplane. Do 10 and then swop directions.
- CRAB WALKING / GREEK DANCING – Holding your arms out for balance move sideways crisscrossing your legs. When your leading leg crosses in front of you, look towards the direction in which you’re heading. Your next step will cause your leading (other) leg to cross behind you. Look in the opposite direction. This movement improves the length of your stride, proprioception and hip mobility. Start by walking and then increasing your speed to a run once you get competent. Do 10 strides each direction.
There are dozens of brilliant dynamic stetch exercises. These will get your started, a book will keep you going.
Incorporating a stretching program into your workout
Begin with a general warm-up. This can consist of movements not directly related to the activity itself i.e. joint rotations, gentle twisting & bending, walking. Here the goal is to increase muscle blood flow, increase your rate of respiration and volume of oxygen intake and to raise your core body temperature.
The duration, frequency and intensity of stretching will depend on your level of flexibility. But, as a guideline…
- Perform two to three repetitions of each stretch for a duration of 10 seconds; or one repetition of each stretch for 30 seconds.
- As training progresses, increases the number of successive repetitions and gradually increase your range of motion.
- As a general rule, non-athletes should stretch at least once a day, three to five days per week to maintain flexibility (more if your want to improve). Depending on the sport, dedicated and serious athletes may require two to three stretching sessions per day for 6 to 7 days per week.
- Within a workout session, gently stretch after a light warm-up, keeping your main stretching session for after the main part of your workout. At this stage your tissue temperatures are highest, making stretching both safer and more productive.
- You decide your stretch intensity. In general, stretch to the point of tension, not pain.
Basic Post-Training Stretch Routine
There are many stretching variations that all work the major muscle groups. I have selected 12 common ones that do the job. The stretch images below have been taken from ‘Alter, M.J. (1998) Sport Stretches (2ed). Human Kinetics. Illinois‘. I have taken the liberty of adding colour. This book has 311 stretches and is well worth buying.
Include a basic stretch routine into your training session, stick with it and you’ll notice the improvement in your performance, recovery and the condition of your muscles.
Author: Lisa de Speville