By Jake Francis
Eccentrics... you folks in the health and fitness industry have likely heard this word before. But, for those of you that have no clue what I'm on about, eccentric movement (or rather contraction) describes a muscle lengthening during contraction under load - basically the muscles that are working when you are lowering a weight.
As an example, there are a few exercises that are commonly used as "eccentrics". These are calf raises - usually prescribed as "stand on a step with your heels of the edge, raise your heel up, then slowly lower yourself down until you feel a stretch in your calves". This is not eccentric exercise... this is placing emphasis on the eccentric phase of a movement. It definitely has benefits:
> It encourages greater control of movement
> You a greater period of time under tension, which recruits more motor units, which increase neuromuscular strength
However, it is not a true eccentric exercise. In eccentric exercise the entire focus should be on eccentric contraction for multiple repetitions, as the name implies. This means we have to create a situation where it is only possible to slowly increase the length of the muscles. Now, in eccentric contraction we can take an awful lot more load than concentric (shortening muscle under load). So, if we take calf raises as the example here, I would suggest taking a heavy weight or weighted vest - one that you can physically lift in a one legged calf raise. Then you will raise your heels up on both legs. Now in that raised position, take one leg away and slowly lower yourself down until you feel a stretch and then support yourself with your second leg again.
I will not deny, this is a horrible exercise... I mean, really.. it's disgusting! However, let's look at the benefits:
> Again, even greater control of the movement
> Heavier load, so even more motor units recruited, and so much greater neuromuscular strength increase
> Far greater stress placed through the lengthening tendons, so you build resilience, so you're far less likely to get injured
It's not just benefits to normal training and injury prevention. Eccentrics (true eccentrics) are the main exercise that should be prescribed with tendinopathies, these are your tennis and golfers elbows, your patellar tendinopathies, and Achilles tendinopathies. Why? Because this exercise encourages far greater stress through the tendons which encourage the fibres to heal in a nice organised longitudinal fashion, and it increases oxygen to the tendon which is needed for all healing. It is rehab that is very uncomfortable, but in the long run it works. You'll end up in no pain and feel stronger and more able to do everyday tasks or your sport. This is currently the best method for tendinopathies, as stated in the research which you can read here.
So why isn't it being used more? Well, the truth is, as many of you might be thinking, this exercise is very difficult to do without the appropriate equipment (ie. heavy weights). This is one reason why exercises with a focus on eccentric movement are prescribed as eccentric exercise. However, the other reason is that people don't understand the difference. This is an issue for therapists, because it will make our notes inaccurate... and we all know how important our notes are (or should know). There is also ways to get around the lack of equipment issue: You can do the exercise normally to fatigue and then, when you can no longer lift up, that's when your eccentric repetitions begin. Can be more fatiguing but it is an alternative.
So, the message is: make sure you understand the exercise you are doing and how you can achieve the benefits of that exercise. If you are being treated for tendinopathy of any kind and your therapist does not know this, find another therapist!