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The Jockology column from a couple of weeks ago discussed the pros and cons of balance training. A Toronto strength coach named Tim Enfield left a comment on the blog yesterday offering a different perspective. Here’s what he wrote:
I noticed that you have an article on unstable training related to athletic performance. I wanted to bring to your attention research on that topic posted on PUBMed, located at http://www.ncbi.nlm.nih.gov/sites/entrez. I believe this study stands in direct contradiction to what you wrote in your blog, and perhaps the writing was misleading to the average gym goer. There is no evidence that for an athletic population unstable devices provide any sort of pre-habilitation function in regards to ankle sprains. For rehab, labile devices are more than appropriate for rehabilitating the stabilzing muscles of the ankle, namely the evertors and invertors, but for the average population the study found they provide little to no significant benefit. Further, in terms of force production the study found that athletes who used unstable training as a training method actually decreased muscular leg force production. If you require the original source, I’d be more than happy to provide it, and to also educate you on better stability training and ankle sprain prehab methods.
First of all, I appreciate the feedback. I’ll have to hold off on a full response until I can see the paper that Tim is referring to (his link above just points to the PubMed site rather than to a specific paper), but a couple of quick points:
There is no evidence that for an athletic population unstable devices provide any sort of pre-habilitation function in regards to ankle sprains.
I don’t doubt that whatever paper he’s referring to failed to find any pre-habilitation function from unstable devices. The problem is that this is an area of research full of conflicting studies, in part because there’s no standard protocol for how such devices should be used. This review of the literature from the journal Sports Medicine looked at 21 such studies. Among their conclusions:
Multifaceted intervention studies that have included balance training along with jumping, landing and agility exercises have resulted in a significant decrease in ankle or knee injuries in team handball, volleyball and recreational athletes… As a single intervention, balance training has been shown to significantly reduce the recurrence of ankle ligament injuries in soccer, volleyball and recreational athletes… Balance training on its own has also been shown to significantly reduce anterior cruciate ligament injuries in male soccer players…
It’s true that no one has demonstrated that balance training, on its own, will reduce the occurence of ankle sprains in people who have never had previous ankle problems. But that’s very different from saying that we’ve proven that balance training doesn’t help. I think any honest appraisal of the full body of literature (rather than a few studies in isolation) will conclude that (a) we still really don’t exactly what balance training helps with and how to maximize its effects, and (b) it’s clear that it does have some injury-reducing potential, in at least some circumstances.
Whether those potential benefits outweighs the downsides is another question. As Tim notes:
(I)n terms of force production the study found that athletes who used unstable training as a training method actually decreased muscular leg force production.
This is a point that I also made in the original Jockology article:
The problem is that if you do a bench press while lying on a Swiss ball, you won’t be able to lift as much weight, so you’ll gain less strength. As a 2007 study of soccer players at the University of Connecticut concluded, training on unstable surfaces “may create a hesitant athlete for whom stability is gained at the expense of mobility and force production.”
So there’s some potential good, and some potential bad — and enough uncertainty that I’d be wary of anyone who claims the research is black-and-white. Personally, I’ve never felt the need to incorporate any instability work into my training — though things like single-leg squats and upper-body free weights provide some of the same stimuli. But overall, I’m pretty comfortable with the conclusion I provided in the Jockology article:
Add up the evidence, and you’re left with a familiar message: moderation. Balance training can be a useful tool to help prevent lower-leg injuries, and perhaps to ward off falls as you get older. But if you spend too much time on the Swiss ball, you’ll be missing out on other training benefits.