Jockology: vitamin C may slow muscle recovery and inhibit fitness gains


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This week’s Jockology column delves into the highly controversial body of research on antioxidants and exercise:

The question

How do antioxidants affect my workout?

The answer

Sales of orange juice are soaring as people seek flu protection from vitamin C, The Globe and Mail reported last month.

Old habits die hard, and our faith in the power of antioxidants is deeply entrenched. Over the past few years, a vast series of studies involving hundreds of thousands of subjects have failed to find any health benefits from antioxidant supplements.

Now, a handful of studies suggest that popping these pills may even block some of the benefits of exercise, and even slow down post-workout muscle recovery. [read on…]

Not to spoil the ending, but to me this research is yet another reason to focus on meeting nutritional needs by eating good foods (in this case, fruits and vegetables) rather than by swallowing pills.

9 Replies to “Jockology: vitamin C may slow muscle recovery and inhibit fitness gains”

  1. I read your article on this at the Globe and Mail – very good stuff! I shared it with a few friends, but like most of the general population they don’t understand why over-supplementing could ever be a bad thing. I would love for you to write a dumbed down version for moms trying to lose weight and guest-post it over on my blog: Lazy Mama Fitness. Let me know if you’re interested – thanks!

  2. Thanks for the comment and the question, Janice. I just got back from a few weeks of holiday, so I’m a bit snowed under right now, but I’ll try to answer in more detail sometime in the next few weeks. I should point out that the research I described in the Globe (about the negative effects of antioxidant supplementation) is still preliminary — by no means is this a topic where all researchers agree! But leaving aside some of those potential pitfalls (delayed muscle recovery, inhibition of insulin response), I personally think the biggest downside of (over)supplementing is that it offers a false sense of security. People taking multivitamins and vitamin C and so on may be less inclined to make the extra effort required to eat enough fruits and vegetables, since they figure they’ve got themselves covered with their supplements. But the evidence is pretty clear that taking pills is nowhere close to a substitute for a healthy, balanced diet.

    Of course, people may say, “With my busy life (or constrained budget or whatever), there’s no way I’ll EVER meet the recommendations for fruit and vegetable consumption, so taking some supplements is better than NOTHING, right?” Well, first of all, the new research I reported in the Globe piece suggests that the supplements may, in fact, have actual negative effects. But even if they’re completely benign, I’m not sure it makes sense to have a $23.7-billion-a-year industry based on the placebo effect (see my Dec. 15 post for more on this). This is where we start to drift away from scientific research and into public health strategy, which is another question entirely. ๐Ÿ™‚

  3. Agreed – I got into an argument about this precise topic with a friend awhile ago. It’s so hard to beat an industry the size of the supplementation industry, isn’t it? They’ve pretty much brain-washed everyone.

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