Homemade sports drinks

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As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- Alex Hutchinson (@sweatscience)

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A few months ago, I promised to look into how to make your own sports drink at home. It has taken me a while to follow up, but I thought I’d pass the following along. From the book “Nancy Clark’s Sports Nutrition Guidebook,” as cited in a New York Times blog entry:

1/4 cup sugar
1/4 teaspoon salt
1/4 cup orange juice
1/4 cup hot water
2 tablespoons lemon juice
3 1/2 cups cold water

In a quart pitcher, dissolve the sugar and salt in the hot water. Add the remaining ingredients and the cold water. The drink contains about 50 calories and 110 mg of sodium per 8 ounces, approximately the same as for most sports drinks.

Do you have the exercise gene?

THANK YOU FOR VISITING SWEATSCIENCE.COM!

As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- Alex Hutchinson (@sweatscience)

***

Last fall, there was a flurry of excitement about the tests being offered by Atlas Sports Genetics, which promised to determine whether you had a predisposition to strength or endurance sports depending on the presence of a variant in the ACTN3 gene. Overbearing parents of young toddlers rushed to sign up.

In a similar vein, it’s now well established that the desire to exercise — the seemingly personal choices we make about whether to spend our leisure hours playing violin or simulating stairclimbing on a machine at the gym — depends to a significant degree on genetic factors. In fact, a 2006 study of more than 85,000 adult twins from seven different countries found that between 48% and 71% of the variance in exercise behaviour is explained by genetic factors.

“So what’s the gene,” you ask, “and do I have it?”

Well, you’re in luck: a new study has been accepted for publication in a future issue of Medicine & Science in Sports & Exercise, titled “Genome-Wide Association Study of Exercise Behavior in Dutch and American Adults.” They did find genetic linkages, and here they are: Continue reading “Do you have the exercise gene?”

Jockology: How long does it take to get fit?

THANK YOU FOR VISITING SWEATSCIENCE.COM!

As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- Alex Hutchinson (@sweatscience)

***

The latest Jockology column is now up on the Globe website:

The question

How long does it take to get “fit?”

The answer

The pair of “before and after” pictures is a staple of fitness hucksterism. Follow our patented program for a few weeks or months, the ads say, and your body will be transformed.

Intrigued by such ads, Megan Anderson and her colleagues at the University of Wisconsin-La Crosse put 25 subjects through an intense six-week exercise program, modelled on claims made by companies such as Bowflex and Body-for-LIFE, in a 2004 study published in the Journal of Strength & Conditioning Research. The subjects’ before-and-after attractiveness was rated by a panel of six judges, who were unable to detect any change whatsoever.

Does that mean six weeks isn’t long enough to reshape your body? Not necessarily.

“The ‘time course’ of fitness changes depends on the training stimulus: intensity, duration and frequency,” says Friederike Scharhag-Rosenberger, a researcher at the University of Potsdam in Germany who published a study on the topic in Medicine & Science in Sports & Exercise earlier this year.

Under the right circumstances, six weeks may be enough. But even if it takes longer, the benefits of exercise start long before you begin to bulk up or run faster.

Here’s what you can expect from different kinds of workouts… [read on here]

Drinking too much during marathons (hyponatraemia): an update

THANK YOU FOR VISITING SWEATSCIENCE.COM!

As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- Alex Hutchinson (@sweatscience)

***

Just noticed a University of London preprint that has been accepted for future publication in the British Journal of Sports Medicine that looks at incidence of hyponatraemia in the 2006 London marathon. This topic has received a fair amount of attention in the past few years (justifiably, since at least five people have died recently in the U.S. and Britain, according to the paper), but there are a couple of new wrinkles in this paper.

First of all, this wasn’t your typical hot marathon where people are pouring fluids down their throat with abandon — the 2006 London race was held in “wet, rainy conditions with air temperature 9-12 [degrees] C.” Still, 11 of the 88 runners studied developed “asymptomatic hyponatraemia,” as diagnosed by low sodium levels. They didn’t have any negative effects — or any symptoms at all, actually — but they were on the border, supporting the contention (the authors claim) that hyponatraemia is underdiagnosed.

As expected, the hyponatraemia sufferers drank more (every mile, most commonly, compared to every second mile for the non-sufferers), and they put on weight during the marathon on average, while everyone else lost weight. But there were some anomalies: four of the hyponatraemics actually lost weight, but still somehow ended up overhydrated. It’s not clear how this happened, though the researchers speculate about “inappropriate antidiuretic hormone (ADH) release during exercise causing altered renal function and secondary fluid retention.”

So what do we take from this? Well, it’s hard to get too worried about an asymptomatic condition that doesn’t cause any problems (though of course if they persist into the symptomatic regime, they risk serious problems). On the other hand, these results tell us that quite a few people are still chugging water well beyond their needs. So maybe it’s worth bearing in mind the words of Tim Noakes, the respected South African sports scientist who has been stirring up dissent about our current obsession with proper hydration: “If you are thirsty, drink; if not, do not,” he wrote in 2007. “All the rest is detail.”

Supplement watch: quercetin for endurance

THANK YOU FOR VISITING SWEATSCIENCE.COM!

As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- 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.