Injuries, antioxidants and more on beets

This article was originally posted by Ryan at the original Blogs.

To think, by Friday morning I was worried that I might not have anything to post this week. Then I got flooded Friday and Saturday morning with some interesting research.

First, a couple studies on injuries:

This meta-analysis of studies on the effectiveness of different kinds of exercises to prevent sports injuries had some interesting results.

In general, physical activity was shown to effectively reduce sports injuries. Stretching proved no beneficial effect, whereas multiple exposure programmes, proprioception training, and strength training, in that order, showed a tendency towards increasing effect. Strength training reduced sports injuries to less than one-third. We advocate that multiple exposure interventions should be constructed on the basis of well-proven single exposures and that further research into single exposures, particularly strength training, remains crucial. Both acute and overuse injuries could be significantly reduced, overuse injuries by almost a half. Apart from a few outlying studies, consistently favourable estimates were obtained for all injury prevention measures except for stretching.

In short, stretching doesn’t appear to be helpful in preventing injury but strength training and proprioception (balance) exercises have very positive effects.

That doesn’t mean that you should stop stretching if you already do so and it feels good. Personally, when I don’t stretch after a run, I feel it during the rest of the day and the next day. That said, don’t just assume it will make you injury free. Better to focus on strength and coordination for injury prevention. What I’m taking home from this is that the proprioception exercises I do sporadically should be a more consistent part of my auxiliary training routine and I should probably be stressing both them and a basic strength routine (something I’ve already been thinking a lot about) more with the runners I coach.

This review of studies (which I found via Running Research Junkie) looks at the causes of injuries. The conclusion kind of speaks for itself:

The main risk factor identified in this review was previous injury in the last 12 months, although many risk factors had been investigated in the literature. Relatively few prospective studies were identified in this review, reducing the overall ability to detect risk factors. This highlights the need for more, well designed prospective studies in order to fully appreciate the risk factors associated with running.

As many of us have surmised for quite some time, the greatest risk factor for injury is prior injury. This is one of the reasons why one of the first questions I always ask a runner I’m new to coaching is about their injury history. I would love to see a deeper dive into why prior injury is such a great risk factor. I have a couple suspicions. First, people tend to rush back too quickly after an injury and re-injure themselves. Second, people often treat the symptoms and not the causes. This results in the underlying cause of the injury still being present when the runner begins running again and the injury recurs.

Other causes mentioned are frequency and volume of running. To me, this isn’t a great surprise. The more you run, the more you risk something happening. Just like the more you walk, the more you risk tripping over your own feet (especially if you have my coordination).

Of note, gender was not associated with higher injury risk in most studies.

On to antioxidants:

This study investigated oxidative stress in cyclists and the effects of antioxidant supplementation.

The data suggest that well-trained athletes with suitable ultra-endurance training volume and intensity do not require antioxidant vitamin supplements to adapt their endogenous antioxidant defenses to exercise-induced ROS.

That pretty much sums it up. Another study that says antioxidant supplementation is unnecessary.

More on beets:

Last week, in my first post of this style, I mentioned beet juice and how it seemed to not help most well trained middle distance runners.

Consider this a follow-up on the topic. This study took an interesting look at nitrate (beet juice extract) supplemtation.

In the study, they took untrained men and had them supplement with beet juice concentrate and a placebo. They then tested these participants for voluntary and involuntary (initiated by electrodes) muscle contraction.

Voluntary contraction force production was statistically similar but involuntary contraction force production, depending on intensity, was either 5-10% greater (at sub-maximal intensities) or 3-15% greater (at maximal intensities).

This is interesting for a couple of reasons. First, it suggests that there is a physiological benefit, at least for untrained individuals, of nitrate. Second, it suggests the central nervous system may somehow counter that so your real world results will not be as greatly enhanced.

Shortly after I read through this, Alex Hutchinson at the Runner’s World Sweat Science blog posted on it and had some interesting insights. Very much worth a read.

It would be very interesting in my opinion to see this kind of test, with voluntary and involuntary force production, done with trained individuals.

Finally, if you see anything interesting, I’d encourage you to comment here with it. Maybe I’ll blog on it next week. If not, at the very least, we can discuss it in the comments.

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