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I have to admit, I was very, very skeptical when I read this report in the New York Times about “performance mouthpieces” that would instantly boost strength, power, endurance, flexibility, reaction time and so on. Alarm bells ring for me when a researcher offers evidence like this:
Previously she “had been happy with running 10-minute miles,” she said, but wearing the mouthpiece, she consistently ran a mile in as little as 8 minutes. “It was pretty astounding to me,” she said. “I didn’t feel as tired as when I ran the 10-minute-per-mile pace.”
So I figured I’d look into the research behind the claims for a Jockology column, which appears today.
What I found was a surprise — in both directions. There was some surprisingly good research that suggests there may be a real effect here. And there was some surprisingly bad research that any company should be embarrassed to promote. The main research cited by Under Armour to back up the claims for its mouthpiece come from a special issue of the far-from-prestigious Compendium of Continuing Education in Dentistry. And not just any special issue — every article in the issue is written by someone who is either an employee or paid consultant of Bite Tech, the company that developed Under Armour’s mouthpieces. This is not research, it’s advertorial.
Here’s an example of what this means, as I describe in the Jockology piece:
The results are interpreted rather generously. What’s described as “a definite trend for lower cortisol” turns out to mean that cortisol levels dropped in only 11 of the 21 cyclists in the study – barely more than half. A follow-up study of runners in 2009 also failed to find any statistically significant change in cortisol.
On the other hand, there is a placebo-controlled, double-blinded crossover study, funded by Makkar Athletics, that found an increase in vertical jump and power in a 30-second cycling test. So, despite my skepticism, there may be something there after all…