Tag: supplements

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

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My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

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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.

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Supplement watch: quercetin for endurance

THANK YOU FOR VISITING SWEATSCIENCE.COM!

My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

***

Quercetin is an antioxidant found in berries, fruit skins, black tea, red wine, and a few other places. It has generated some excitement because it has been shown to increase the production of mitochondria and enhance running endurance by 37 percent in mice. Human studies (it almost goes without saying) have produced less spectacular results — and now an excellent double-blind, placebo-controlled trial by researchers at the University of Georgia, published in the Journal of Applied Physiology, has failed to find any effect on a whole series of athletic performance markers in humans.

“We did not see any performance enhancing effect of quercetin,” [researcher Kirk] Cureton said. “To a certain extent that was disappointing because our hypothesis, based on previous studies in mice, was that we would see positive effects. But our findings are important because they suggest that results from the animal studies shouldn’t be generalized to humans.”

The press release (from which the above quote is taken) is unusually well-written and provides lots of details on the study and its significance and context. The researchers cast their net pretty widely, looking for possible effects. They measured:

  • The rate at which muscles synthesize energy after strenuous exercise;
  • Peak oxygen consumption;
  • The rate of perceived exertion during cycling;
  • Metabolic changes, such as the percentage of energy derived from fats and carbohydrates (more conditioned individuals tend to use more fat for energy);
  • Performance on a cycling test; and
  • Strength loss following prolonged cycling.

In none of these cases did they find any performance enhancement. The last word to the researcher:

“The take home message here is that promising results in mice don’t necessarily translate to humans,” Cureton said.

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Antioxidant vitamins, exercise and muscle damage: another nail in the coffin?

THANK YOU FOR VISITING SWEATSCIENCE.COM!

My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

***

Back in May, there was a flurry of excitement about a study suggesting that antioxidants might block some of the beneficial effects of exercise (heightened insulin sensitivity, to be specific). A new study in this month’s issue of Medicine & Science in Sports & Exercise now offers additional evidence for another proposed downside of antioxidant supplementation. According to a University of Porto study of 20 kayakers on the Portugese national team, popping anti-oxidant pills may delay muscle recovery.

Here are the details of the study. Continue reading “Antioxidant vitamins, exercise and muscle damage: another nail in the coffin?”

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Beet juice boosts endurance

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My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

***

Today’s “exercise in a bottle” study: beet juice can help you exercise for up to 16 percent longer, according to researchers at the University of Exeter.

After drinking beetroot juice the group was able to cycle for an average of 11.25 minutes, which is 92 seconds longer than when they were given the placebo…

The researchers are not yet sure of the exact mechanism that causes the nitrate in the beetroot juice to boost stamina. However, they suspect it could be a result of the nitrate turning into nitric oxide in the body, reducing the oxygen cost of exercise.

For the record, the study consisted of eight men, who took 500 mL of beet juice for six straight days. The presence of nitrate isn’t something I’d ever heard of before, so maybe there’s some new science here. Certainly, the researchers seem to be pretty excited about it.

“We were amazed by the effects of beetroot juice on oxygen uptake because these effects cannot be achieved by any other known means, including training. I am sure professional and amateur athletes will be interested in the results of this research,” [said Professor Andy Jones].

My personal prediction: don’t look for Tour de France riders or Olympic runners to be downing beet juice anytime soon. I’d stick with training.

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Vitamins and exercise don’t mix? (and rehabilitating free radicals)

THANK YOU FOR VISITING SWEATSCIENCE.COM!

My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

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A new report in the latest issue of the Proceedings of the National Academy of Sciences has caused a stir. As Scientific American puts it,

Exercise is good for you. Antioxidants are good for you. But put them together and it’s not as good as you’d think. Because a recent study shows that some vitamins block the beneficial effects of exercise.

Continue reading “Vitamins and exercise don’t mix? (and rehabilitating free radicals)”