Good science vs. bad science in fitness claims

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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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The latest Jockology column in the Globe and Mail is now available online:

Pretty much every fitness product claims to be “backed by science.” But a recent spate of lawsuits against the makers of Power Balance bracelets highlights how empty these claims can be. Even for companies trying to do the right thing, navigating the complexities of scientific evidence can be a challenge, as the following examples illustrate…

The examples are Power Balance bracelets, Athletic Propulsion Labs’ “banned” basketball shoes, Reebok’s “oxygen-enhancing” ZigTech clothing, Gatorade’s claim that drinks with electrolytes help reduce the risk of hyponatremia, and — my favourite these days — beet juice’s endurance-boosting effects. There’s also a nice supporting graphic from Trish McAlaster.

The physiology of aquafit (and pool running)

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)

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This week’s Jockology column looks at the physiological differences between land- and water-based exercise — aquafit, water running and activities where you’re vertical in the water rather than horizontal like swimming:

[…] The differences between water and land might seem obvious, but there are some subtleties. For example, the pressure exerted by water against your body is strongest at the bottom of the pool, where your feet are, and weakest at the top. This pressure gradient helps push blood back towards your heart, making its job easier. [Read the whole article…]

The article focuses mainly on the advantages of water-based exercise for people with balance, joint or weight concerns that make land-based exercise more difficult. But there’s a special bonus for pool-running aficionados: a brutal 60-minute workout that Canadian mile record-holder Kevin Sullivan used when he had a stress fracture in his sacrum. He got it from 1984 Olympic bronze medalist (and fellow Michigan alum) Brian Diemer, who relied on it to stay in shape prior the 1984 Olympic Trials — Diemer apparently had a stress fracture and came out of the pool only three weeks before the Trials, but was still fit enough to make the team and go on to medal later that summer.

I did it myself, every third day, when I had a sacral stress fracture in 2004. There’s something about the symmetry of the workout that I love — I’m always surprised when all those parts manage to add up to exactly 59:55.

Predictions (and story ideas) for sports science in 2011

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)

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I did a little crystal-ball gazing (some might call it navel gazing) in my column in today’s Globe, picking 10 topics in sports science that I think we’ll be hearing about in 2011:

It’s January, which means the gyms are full of exercisers resolving that 2011 will be the year they meet their fitness goals. In labs around the world, meanwhile, exercise scientists are resolving to settle some of the fitness questions that still dog us. Here are 10 confusing, contradictory, or just plain complicated areas of exercise science that will see significant progress in 2011… [READ THE WHOLE COLUMN]

Most will be familiar to regular readers of Sweat Science, since I think the best predictor of what researchers will be studying is which topics we’ve been discussing and arguing over the past few years. Needless to say, I’d love to hear suggestions of what I missed — which also doubles as a request for ideas for future columns, blog entries and so on. What sports science topics would you like to hear more about in 2011?

(One “miss” that I’ll mention: I didn’t include the debate over running shoes and the ideal stride, even though I’m sure it will remain a hot topic, because I’ll be revisiting it in a couple of columns next month.)

Circadian rhythms and athletic performance

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)

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The latest Jockology column is posted on the Globe and Mail site (it won’t actually appear in the paper until this coming Thursday due to a schedule change, so you’re getting a sneak peak online!). The topic is circadian rhythms — how they affect physical performance, and how you can alter them. An excerpt:

[…] A 2007 study by Tunisian and French researchers found that power in an all-out 30-second cycling test was lowest at 6 a.m., then increased steadily through the day until it was about 10 per cent higher at 6 p.m., then fell steadily. A long list of earlier studies had found similar effects in back and arm strength, vertical and broad jump, and also in sports ranging from swimming to badminton, with the peak time always within a few hours of 6 p.m.

This effect may be partly a function of time awake (you’re groggy early in the day and tired later in the evening) and eating patterns (you won’t be at your best before breakfast or immediately after lunch).

But more subtle circadian rhythms, such as the daily change in core body temperature, also play a role, Dr. Sleivert says. Studies have found that body temperature rises by about 1 C between early morning and late afternoon, which may help loosen muscles and swell blood vessels in the same way a pre-exercise warm-up does… [READ THE WHOLE ARTICLE]

A related topic is how athletes deal with jet-lag, which is covered in an info-graphic that accompanies the piece (but doesn’t seem to be included online). I looked into some of the research on melatonin (the hormone that basically tells the body that it’s nighttime), and found it convincing enough that I decided to give it a try. By coincidence, I flew to London last night/this morning, so I’ll have a chance to give a try when I go to bed in a few hours. Here’s hoping for a melatonin miracle and a good night’s sleep!

Jockology: training for soccer

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)

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This week’s Jockology column rounds up a bunch of research on the optimal preparation and training for soccer: the mechanics of kicking, the physiology of repeated short sprints, the psychology of penalty kicks, the optimal warm-up and nutrition, rapid direction changes, etc. It’s in the form of a big infographic, put together by Trish McAlaster, the talented artist I often work with at the Globe. (We’re currently working a pretty cool graphic for the next column — stay tuned!)

Most interesting bit of info in the current column, for me, was this: when you run a short sprint, you get about 20% of the ATP you need from aerobic processes, and 80% from anaerobic processes. But if you keep sprinting (as you would for a soccer game), the third sprint is already 50% aerobic/50% anaerobic, and the “Nth” sprint is 75% aerobic/25% anaerobic. So if you want to be fast late in the game, you need to fuel yourself like an endurance athlete.

(This info comes from Stuart Phillips‘ chapter in the book Sports Nutrition: From Lab to Kitchen. And I actually simplified the info a bit for the column by combining the contributions from phosphocreatine with other anaerobic sources. The actual split for aerobic/anaerobic/phosphocreatine is 20/30/50 for the first sprint, 50/20/30 for the third, and 75/5/20 for the Nth.)