Tag: supplements

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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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The U.S. government plans to spend $1 billion on a new NIH centre on “Advancing Translation Sciences.” Great news, right? Not according to James Hebert and Steven Blair of USC, who have a new commentary just posted online at the British Journal of Sports Medicine:

This plan typifies the search for a ‘magic bullet’, in pill form, that will cure all diseases and health problems…

[L]arge drug companies have spent ~US$400 billion on drug research over the past 15 years. We should examine the effectiveness of this huge expenditure in terms of public health benefits… What happens in a society in which people are told that pills are available to put them to sleep, wake them up, stimulate them, calm them down and control appetite and body weight? We argue that the answer is in the growing number of people with mental disorders including depression and anxiety, sleep disorders, deteriorating nutritional status and increasing rates of obesity unprecedented in human history. The pills that have been developed, advertised on television and demanded by a desperate populace have been spectacular in their inability to address the major and growing public health problems of the USA.

Instead, Hebert and Blair want to see more emphasis on lifestyle change. They cite some interesting data from studies comparing lifestyle and pharmaceutical interventions. For example, a study found that just three or four sessions with a dietician produced the same reduction in total and LDL cholesterol as taking statins. And two randomized trials found that “lifestyle interventions” were twice as effective as drugs in preventing high-risk individuals from developing diabetes. The authors are “puzzled and concerned” that results like these haven’t received more publicity and follow-up.

So what’s the solution? They suggest an NIH “National Institute for Improving Healthy Lifestyles” instead of the translational medicine institute. Would this make a difference? It seems to me that if we knew how to get people to change their lifestyles, we’d already be doing it. But perhaps they’re right: with enough resources — and $1 billion would be a pretty good start! — maybe lifestyle change wouldn’t look quite so daunting.

We understand that while changes in diet and physical activity are conceptually easy, they are diabolically difficult to do in practice. The promise of even easier solutions to cure the consequences of years of sloth needs to be debunked.

That, I think, is the key point. We need to stop promising that getting healthy will be easy, and emphasize instead that it’s worthwhile. To borrow a thought from physics, it’s like that Einstein quote: “Everything should be made as simple as possible, but not simpler.”

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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Just when I thought I’d extricated myself from the great “bike helmets and risk homeostasis” debate, along comes a study suggesting that taking multivitamin pills causes people to behave in less healthy ways for the rest of the day. Even worse, the title of the paper in Psychological Science (“Ironic Effects of Dietary Supplementation: Illusory Invulnerability Created by Taking Dietary Supplements Licenses Health-risk Behaviors”) is likely to start an even fiercer debate about the correct use of the word “irony.” (Maybe it’s just a pun, since some multivitamins contain iron.)

But seriously, folks… The researchers gave a bunch of volunteers a harmless placebo pill; half of them were told it was a placebo, while the other half were told it was a multivitamin. Then they did some experiments and found that those who thought they’d taken a multivitamin “expressed less desire to engage in exercise and more desire to engage in hedonic activities, preferred a buffet over an organic meal, and walked less to benefit their health than the control group.”

It would be silly to take this study as evidence that multivitamins are “bad.” Still, I can’t help feeling that it does point toward a trade-off that people may unconsciously make when they look for “exercise pills” and other shortcuts. Most of the athletes I know take multivitamins as a way of “covering their bases” in case their diet falls short — as, in the real world, it occasionally will. But are there times when it only falls short because they feel that it’s okay to cut corners because they’ve got the pills as back-up? That’s what this study suggests. Maybe it’s better to take away the safety net, so you have more motivation to stay on top of your diet.

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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The traditional theory goes like this: strenuous exercise produces “reactive oxygen species” (ROS), which cause damage to cells and DNA in the body. Taking antioxidant supplements like vitamins C and E helps to neutralize the ROS, allowing the body to recover more quickly from workouts.

The new theory, in contrast, goes like this: strenuous exercise produces ROS, which signal to the body that it needs to adapt to this new training stress by becoming stronger and more efficient. Taking antioxidant supplements neutralizes the ROS, which means the body doesn’t receive the same signals telling it to adapt, so you make smaller gains in strength and endurance from your training.

So which is true? Back in 2009, a German study found that vitamins C and E did indeed block gains in insulin sensitivity — a key adaptation to exercise — in a group of sedentary volunteers. But in January 2010, a study of cyclists found no difference in fitness parameters like maximal oxygen consumption, power output, lactate threshold and so on between a placebo group and a vitamins C/E group. But then last December, a study with rats found that vitamin E did block gains in mitochondria, a key adaptation to endurance training.

Which brings us to the most recent study, published in March in the International Journal of Sports Physiology and Performance. A total of 17 recreational runners did a four-week training program consisting of four interval workouts a week (5x3min hard with 3min jog recovery — a bit of an odd program, but it succeed in significantly boosting VO2max, running economy, 10K time trial performance, etc.). Half the subjects took 1 gram of vitamin C every morning, while the other half took a placebo; the trial was double-blinded, so no one knew who was in which group. The results: no significant differences between the groups.

So where does this leave us? I’m not really sure. The paper discusses a couple of possible explanations. One is that antioxidants do block some training gains but that this study was too small to detect them. With nine subjects in one group and eight in the other, that’s certainly possible. For example, the subjects ran two  “YoYo Intermittent Recovery Tests” with slightly different parameters. In the first one, the vitamin C group improved 22% while the placebo group improved only 16%; in the second one, it was the other way around, with the placebo group improving 10% and the vitamin C group improving only 5%. This doesn’t give me a whole lot of confidence in the test-retest variability, or the ability to detect subtle differences in adaptation.

Another possibility relates to the initial fitness of the subjects. The 2009 German study used sedentary, unfit subjects, who thus would be expected to produce very high levels of ROS in response to the unfamiliar stress of exercise. In these subjects, one might expect antioxidant supplements to make a bigger difference to training adaptations. The new study, on the other hand, used subjects with higher initial aerobic fitness (“recreationally active,” not trained athletes). As the saying goes, “exercise is the most powerful antioxidant we have.” So it’s possible that fit subjects already have reasonably effective natural antioxidant defenses in place, so taking additional antioxidant supplements doesn’t make as much (or any) difference.

All of this leaves us with no firm answer — as usual, more studies are needed. My guess (thinking back to my last post about the pros and cons of training on empty) is that we’ll eventually conclude that the answer is “it depends.” Perhaps antioxidant supplements will be helpful during extremely heavy training blocks, but should be avoided as you approach competition. Or perhaps it’s the other way around: let the ROS run wild during heavy training blocks, but take antioxidants to ensure full repair as competition approaches. The latter approach fits with a Portugese study that found that antioxidants may delay muscle repair after heavy workouts, but could allow muscles to actually work harder in the heat of competition. It’s too soon to know for sure.

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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Wow. This study is really impressive. Drinking 500 mL of beet juice 2.5 hours before a cycling time trial improves 4 km TT time by 2.8% and 10 mile TT time by 2.7%. On the one hand, this shouldn’t be surprising, because there have been a bunch of recent studies showing beet juice boosting time-to-exhaustion and reducing oxygen cost… But still, those types of studies often don’t end up translating into real differences in the parameter that matters: actual performance. So, as I said: Wow.

The study, published online last week in Medicine & Science in Sports & Exercise, is legit. It’s from Andrew Jones’s group in Exeter. It’s a properly designed placebo-controlled crossover study. The placebo was beet juice with the nitrates (the active ingredient) filtered out with an ion resin, thus indistinguishable from the active beet juice. The subjects (nine competitive cyclists) visited the lab at least five times before the actual experiment even started, to practice taking the time trials until they achieved repeatability of less than 1%.

To reiterate what’s most striking:

• Performance benefits of 2.8% (6.26 vs 6.45 min) over 4 km and 2.7% (26.9 vs 27.7 min) over 10 miles.
• This improvement was achieved with just one dose of 500 mL of beet juice, taken 2.5 hours before the event. (Note that this dose is equivalent to 1.6 kg of spinach or 3.1 kg of lettuce!)

They also took other measurements: the amount of oxygen used was the same with and without nitrates, but the power generated was higher with nitrates. Also, plasma level of nitrites was higher after the beet juice, consistent with previous studies suggesting that the beet juice works because nitrates are converted to nitrites then to nitric oxide, which lowers the oxygen cost of muscle contractions.

On another note (further to this previous post):

The subjects also abstained from using antibacterial mouthwash and chewing gum during the supplementation periods since these are known to eradicate the oral bacteria which are necessary for the conversion of nitrate to nitrite.

So what more is there to say, other than “Buy stocks in beet juice companies pronto”? Well, one caveat is that it hasn’t yet been shown that these results can be duplicated in elite athletes. It’s notoriously easier to produce big improvements in less-trained athletes, and these subjects were recreationally competitive. So further studies will be required in elites. But it’s time to acknowledge once again that my initial predictions when I first heard about this research in August 2009 were wrong, wrong, wrong!

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)

***

The performance-boosting effect of beet juice, attributed to the nitrate it contains, has been one of the biggest sports science stories of the past year. A few days ago, Swedish researchers published a new study in the journal Cell Metabolism (press releases here and here) that answers some questions about how nitrate works — and raises some questions about whether mouthwash might actually hurt your performance. Interestingly, this Swedish group has been publishing results on the performance-boosting effects of nitrate since 2007. It’s only when Andrew Jones’s group at the University of Exeter started publishing results in 2009 using beets instead of isolated nitrate that everyone started paying attention.

The study: a randomized, double-blind crossover trial with 14 subjects given either 0.1 mmol/kg of sodium nitrate or a placebo each day for three days. Since their previous studies have shown that this protocol allows subjects to use less oxygen while cycling at a given intensity, this time they looked for the root cause. They isolated mitochondria (the cellular “power plants” that generate ATP to fuel muscle contractions) in the subjects. Sure enough, the mitochondria from the nitrate group used less oxygen to generate a given amount of ATP. Further (rather complicated) experiments suggested that this is because nitrate leads to lower levels of a protein that causes efficiency-sapping proton leakage across the mitochondrial membrane.

So what does it mean? Well, the researchers suggest that it might be nitrate (which, as they note, “has previously been considered merely as an inert end product of NO metabolism or as a potentially toxic constituent in our diet” — think hot dogs) that is responsible for the well-known but poorly understood health benefits of a diet high in vegetables (particularly leafy green ones). And of course, it’s more evidence that nitrate might be the real deal as an ergogenic aid for endurance athletes.

But what really caught my attention was the following offhand remark in one of the press releases:

As an interesting aside, Weitzberg says that the benefits of dietary nitrates suggest that powerful mouthwashes may have a downside. “We need oral bacteria for the first step in nitrate reduction,” he says. “You could block the effects of inorganic nitrate if you use a strong mouthwash or spit [instead of swallowing your saliva]. In our view, strong mouthwashes are not good if you want this system to work.”

Huh? Here’s a brief explanation from the paper itself about how nitrate is used by the body:

Circulating nitrate, normally derived both from endogenous NO [nitric oxide] production and from dietary intake, is actively taken up by the salivary glands, excreted in saliva, and reduced to nitrite by commensal bacteria in the oral cavity.

The statement about mouthwash having a negative effect is just speculation at this point, not backed up by any studies. But it’s interesting…

UPDATE Feb. 9: Thanks to Colby for pointing out that the same Swedish group has actually already done a study looking at the effects of mouthwash, published back in 2008. The gist is as follows: the nitrate we take in through our diet is converted first to nitrite then to nitric oxide, which is what has a positive effect on blood pressure, performance and other parameters. But our cells are unable to convert nitrate to nitrite — to make that conversion, we rely almost exclusively on friendly bacteria in our saliva. To test that hypothesis, the researchers fed nitrate (the equivalent of about 300 g of spinach or beets) to volunteers 15 minutes after they gargled with an antibacterial mouthwash (Corsodyl). Here’s what they saw:

Even though nitrate levels in saliva were similar, the bacteria needed to convert nitrate to nitrite was gone in the mouthwash experiments, so nitrite levels in saliva remained flat. As a result, nitrite levels circulating in the blood (which is what’s shown above) increased far less in the mouthwash than the non-mouthwash case.

Unfortunately, this still doesn’t tell us much about timing and chronic effects. If you mouthwash before bed, will your nitrate-to-nitrite conversion still be impaired at dinner the next day? I really don’t know. I’m certainly going to keep mouthwashing — but it might make me think twice about the gratuitous middle-of-the-day extra gargle!