alex – Page 103 – Sweat Science

August 11, 2009

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)

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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.

August 11, 2009

CRMag: massage and lactic acid, Achilles debridement, reading on the treadmill and more

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- Alex Hutchinson (@sweatscience)

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The September-October issue of Canadian Running magazine is back from the printers, and should be in the mail and on newsstands soon. As usual, lots of good stuff — a profile of Ray Zahab, a pilgrimage through the three big-city U.S. fall marathons, and a Q&A with the ever-entertaining Reid Coolsaet, who’s currently in Berlin to run the marathon at the World Championships. Also, our editorial director, Dave Chaundy-Smart, tried out the Internet coaching offered by legendary Olympic marathoner Jon Brown. And finally, my regular Science of Running column covers the relationship between vitamins and exercise, a new gadget for reading on a treadmill, a new approach to Achilles tendinitis, the physiology of massage, and good news about marathons and heart damage.

August 10, 2009

Barefoot running: theory versus practice

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- Alex Hutchinson (@sweatscience)

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With the publication of Chris McDougall’s Born to Run this spring, there’s been a flurry of interest in barefoot running (or minimalist running, which involves donning ultralight shoes like the Vibram FiveFingers, whose function is to keep your soles clear of broken glass and doggie doo rather than support your ankles). I had an interesting chat with McDougall for an feature I wrote in the July-August issue of Canadian Running (an excerpt is available here, but the full article isn’t available online at this point). I mention this because a reader just forwarded me a good overview of the topic from Wired, which offers its usual research-backed take on the topic [thanks for the tip, Adam].

To me, the jury is still out on this one. I like the theory behind minimalist running, and am willing to believe that, for those who take the time to build up slowly and do it right, it may be a route to injury-free running. But in practice, I’m not convinced that it’s widely applicable in our concrete-covered world, especially for people who have grown up wearing shoes. The extreme patience and diligence needed for a successful transition to barefoot running are precisely the qualities that most of us fail to demonstrate when running in regular shoes — which is why we get injured in the first place. So I think minimalism will remain a minority option for a small group of very methodical people who have tried and failed to run injury-free in regular shoes, but are truly committed to finding a way to run.

August 2, 2009

Running marathons makes your memory worse…and better

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- Alex Hutchinson (@sweatscience)

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This is a neat paper on how running affects the mind, with a surprise twist. (Check out Frontal Cortex and Neurocritic for more detailed discussions.) Researchers at Columbia University wondered whether the extreme stress of running a marathon might trigger hormones in the brain that would temporarily alter how our minds work. It’s a reasonable assumption:

Indeed, [the researchers write] cortisol levels recorded 30 min after completion of a marathon rival those reported in military training and interrogation (Taylor et al., 2007), rape victims being treated acutely (Resnick, Yehuda, Pitman, & Foy, 1995), severe burn injury patients (Norbury, Herndon, Branski, Chinkes, & Jeschke, 2008), and first-time parachute jumpers (Aloe et al., 1994).

So does running disrupt your memory? Yes. The researchers tested Boston and New York marathon participants, either a few days before their race or within 30 minutes of finishing, and the post-race tests showed worse performance on a set of verbal memory tests. That’s an example of “explicit memory,” where you consciously remember events and facts. But here’s the surprise: the researchers also found that the post-race testees did better on tests of “implicit memory,” which is how you store information that you don’t need to access consciously, like how to ride a bike.

In other words, it appears that being under stress (and marathons definitely count as stress!) causes you to tap into the older, reptilian part of your brain, where instinct and intuition dominate.

[Thanks to Kyle for the tip. I’m heading out the door in a few hours for a week-long canoe trip, so expect the next blog update around August 10. Happy long weekend!]

August 1, 2009

Running to prevent glaucoma, cataracts and macular degeneration

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- Alex Hutchinson (@sweatscience)

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For the last 18 years, Paul Williams of Lawrence Berkeley Laboratory has been following 55,000 runners as part of the the National Runners’ Health Study, which has incredible statistical power thanks to its size and duration. These days, Williams churns out new studies like clockwork, showing the association of running with various health risks and body parts. Most recently, it’s the eyes: in three separate studies (one in Medicine & Science in Sports & Exercise, two in Investigative Ophthalmology and Visual Science), Williams shows that running reduces the risk of glaucoma, cataracts and macular degeneration. The mechanism isn’t entirely clear (epidemiological studies like this shows correlations, not causes), but Williams speculates that aerobic exercise may reduce “intraocular pressure,” the fluid pressure behind the eye.

What Williams really emphasizes in his recent studies is the “dose-response” relationship between running and health: the farther and faster you run, the greater the benefits. In this case, for instance, every additional kilometre in your average daily run lowers your glaucoma risk by five percent. Also, the faster your best 10K time, the lower your risk — in fact, there were no reported cases of glaucoma for runners who could run 10K faster than 33:20! This is quite different from the usual government health recommendations that advocate a fairly minimal amount of moderate exercise each week, and make it sound like there’s no particular benefit in doing more.