Antioxidants block gains from endurance training


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Another study on antioxidant supplements, this one from researchers at the University of Queensland in Australia, published online in Medicine & Science in Sports & Exercise.

The study was with rats: 14 weeks of supplementation with vitamin E and another antioxidant called alpha-lipoic acid, training four times a week. The antioxidants suppressed the growth of new mitochondria (the “power plants” of your cells), which is one of the primary adaptations to endurance training. One of the new wrinkles to this study compared to previous ones is that growth of mitochondria was suppressed even in rats that weren’t training, if they took the supplements.

I’ve written several times before about this area of research. The idea is that “reactive oxygen species” (ROS) are generally bad, and antioxidants fight them. But when you exercise, the ROS you produce are the “signals” that tell your body to adapt, so if you take antioxidants, your body doesn’t realize it’s supposed to adapt and get stronger (or grow more mitochondria or whatever).

The conclusions are far from clear — for instance, this study didn’t find any reduction in the benefits of endurance training from antioxidants. But given how little evidence there is that these types of supplements actually help, the potential costs certainly seem to outweigh the benefits.

5 Replies to “Antioxidants block gains from endurance training”

  1. This is inline with my other philosophies that inhibit adaptation like anti-inflammatory and correction shoes so I’m not sure why I’ve been taking a vitamin E supplement all those years. Should I stop eating blueberries and green tea?

  2. Did the study mention anything about antioxidants coming from real food? I think I read somewhere that coming from real food is no problem, but I’m just making sure.

    Also,if the ROS you produce signals for adaptations, and it’s exactly that you’re trying to not lose by taking an antioxidant supplement, what if you were to take ROS after exercising (assuming you can somehow take it), would you achieve greater adaptations? Just thinking out loud…

  3. Very interesting post but I’m unclear – the first paragraph says that the antioxidants (vitamin e specifically) may suppresses at least some of the benefits of exercise.

    Then, the third paragraph says, “this study didn’t find any reduction in the benefits of endurance training from antioxidants.”

    The post is fascinating but can you please clarify this contradiction for me?


  4. Thanks for the comments, folks, and apologies for the delayed replies – just back from a four-week hiking trip in Nepal. Richard and Andy, the question about real food versus antioxidant supplements is a very interesting one. The most common response is the Michael Pollan one: foods are very complicated, so we’re not really capable of isolating one or two ingredients and getting the same benefits we get from food. There’s no doubt whatsoever that antioxidant-rich foods like fruits and vegetables have lots of benefits (i.e. reduction in cancer rates), but it seems that there’s something about whole foods — the precise mix of chemicals or something — that gives you a benefit you can’t get from antioxidants alone.

    On the other hand, when I asked Michael Ristow (one of the pioneering researchers in this area) this question, he had a different take. He thinks antioxidants are unequivocally bad, and the health benefits of fruits and vegetables must come from other chemicals in them.

    So, as usual, more research needed…

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