Antioxidants and fitness vs. efficiency

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

A long lasting debate and an important reminder this week.


First, the reminder.

Back when I was a relatively new runner, everyone believed antioxidants were very good for runners. The belief was the more, the better. Antioxidants would help you recover from your training faster, which would allow you to train harder.

Conceptually, this makes great sense. In fact, upon a recommendation from a doctor who was also a good runner, I took mega doses of antioxidants for many years. I have to wonder now, though, in the face of more recent evidence how much those mega doses of antioxidants may have harmed my fitness.

Well, here’s more to get me thinking:

On the basis of vitamin E and NAC studies, acute intake of antioxidants is likely to be beneficial. However, chronic intakes of most antioxidants have a harmful effect on performance.

So short term supplementation may make sense. Long term? Forget it. It’s likely to do more harm than good.

Fitness vs. efficiency

There’s been a long debate over whether increased fitness decreases one’s efficiency. On one hand, it wouldn’t seem that one would directly affect the other. On the other hand, it seems that the people with the best fitness as measured by VO2max are not those with the best running economy. Even the elites tend to be great in one or the other but not both.

There is some new research that took a look at two questions:

1) If you have a high VO2max, are you more likely to have a lower running economy?

…there is an inverse relationship between VO2 max and running economy: those who are good in one are less likely to be good in the other. But it’s a pretty scattered relationship. Overall, knowing someone’s VO2 max accounts for only seven percent of the variance in their running economy. The rest is determined by other factors.

So the answer is yes but not by a significant margin.

2) If you improve your VO2max, does that mean you’re more likely to make your economy worse?

Again, those who improved VO2 max were slightly less likely to improve running economy. In this case, knowing the change in VO2 max explained 12 percent of the variance in running economy changes.

Again, yes but not by much.

So it’s true that a better VO2max apparently is associated with worse running economy but the relationship is weak. It’s not a death knell. You can improve both at the same time and you can do well in both measures.

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