Soccer science

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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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When I went out for my run this morning, Sydney seemed like a ghost town: empty sidewalks, tumbleweed blowing down the streets, etc. The only signs of life were in the pubs, which had been open since 4 a.m. for the Socceroos’ Monday-morning World Cup debut. Inside, people were huddled quietly over their empty schooners, absorbing their 4-0 loss to Germany.

In that spirit, a couple of good recent articles on the science of soccer:

– Ross Tucker of The Science of Sport has started a series on the physiology of soccer. The first installment offers a good profile of what it takes to play a full game: running 10 to 15 km, including between 80 and 110 sprints, and so on. I had a chance to chat with Ross for a couple of hours last week for an upcoming article — a very interesting guy with lots of insight, as you can gather from the blog.

– A very thorough round-up of recent research on the psychology of the penalty kick, by Andrew Keh of the New York Times. As I write this, Ghana has just taken the first penalty kick of the tournament, scoring to defeat Serbia — but we’ll be seeing a lot more of these when we reach the elimination rounds. One of the most interesting observations:

Kick takers in a shootout score at a rate of 92 percent when the score is tied and a goal ensures their side an immediate win. But when they need to score to tie the shootout, with a miss meaning defeat, the success rate drops to 60 percent.

“This to me is the key finding of all our studies,” said Geir Jordet, a professor at the Norwegian School of Sport Sciences in Oslo who has analyzed shootouts with fervor. Jordet also found that shooting percentages tend to drop with each successive kick — 86.6 percent for the first shooter, 81.7 for the second, 79.3 for the third and so on.

“It demonstrates so clearly the power of psychology,” he said

How to taper for a race, and why it works

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 research into tapering: how to reduce your training before an important competition so that you’re well-rested but don’t lose any fitness. It tackles how long you should taper for (two weeks seems to work well); how you should adjust training volume (reduce by 40 to 60 percent), intensity (don’t change) and frequency (don’t change); and the difference between step, linear and exponential tapers.

The most interesting finding for me came from a new study by Scott Trappe and his colleagues at Ball State’s Human Performance Laboratory, suggesting that tapering isn’t just about rest — it actually helps your muscles grow:

He and his colleagues took a series of muscle biopsies from university cross-country runners preparing for a championship race. Surprisingly, they found that the individual muscle fibres responsible for explosive power in the legs actually got bigger and contracted more powerfully after the training reduction.

“On a molecular level, the wheels are so greased that the engines proceed at a high rate even after you reduce your training,” explains Dr. Trappe. This creates a window of opportunity during which the delicate balance between muscle synthesis and breakdown shifts to favour muscle growth.

In contrast, the researchers found no change in measures of cardiovascular endurance such as VO2max. This suggests that it’s the muscle adaptation that provides the performance boost of tapering – and just as importantly, that a brief period of less training doesn’t compromise endurance. The result: The runners raced 6 per cent faster over 8 kilometres than they had just three weeks earlier. [read the rest of the column]

Weak hips cause runner’s knee

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’m looking forward to going through the research presented last weekend at this year’s ACSM meeting. For starters, a study presented by researchers from the Indiana University found that hip strengthening exercises reduce or eliminate “patellofemoral pain” (“runner’s knee”) in female runners. This is an idea that has been gaining momentum over the past few years — I first heard about it back in 2007 from Reed Ferber of the University of Calgary’s Running Injury Clinic (and wrote about it here).

The Indiana study is pretty small — just nine runners, with the five who did the hip strengthening exercises lowering their pain score from 7 to 2 or lower (on a scale of 0 to 10) after six weeks of twice-a-week strengthening. The researchers are hoping to try the same program on a larger group of runners. Normally I wouldn’t get too excited about such a small study, but given that the idea is also being developed elsewhere (such as this study about hips strength and knee arthritis that I blogged about last year), it’s starting to look pretty interesting. I suffered through an extremely persistent case of runner’s knee a decade ago that kept me out of competition for almost two years, so I certainly wish I’d known about the possibility that hip exercises might help.

If you want to give them a try, here are Reed Ferber’s suggested hip exercises [pdf, 2 MB].

Barefoot running and the difference between biomechanics and injury rate studies

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)

***

I just noticed that a short article I wrote for Canadian Running‘s May/June issue is now available online. It’s my attempt to provide some context for the studies on barefoot running that made lots of (somewhat wild) headlines at the beginning of the year. It doesn’t offer any definitive conclusions, mainly because I don’t think such conclusions yet exist. My main point is the distinction between biomechanical studies and injury-rate studies. Everyone has been beating up on the shoe industry for years because it relies on the former rather than the latter — but that distinction is suddenly being “forgotten” now that biomechanical studies supporting barefoot running are appearing.

A short excerpt:

[…] There’s no doubt that thinking on footwear has evolved in the last decade or two. For instance, plush cushioning is no longer considered the ultimate defence against injury. “I wish running companies would stop rattling on about ‘gel’ and ‘air’ and so on,” says Simon Bartold, an Australian shoe researcher who consults for Asics. Newer shoes reflect this thinking, he says: Nike has introduced the Free, for example, and Asics has completely abandoned the concept of “motion control.” But rushing to the opposite extreme and claiming that runners of all shapes and sizes should give up shoes makes no sense either – and the new studies certainly don’t support this position. […]

“Heart rate recovery” and acute vs. chronic training fatigue

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)

***

I had a chance to see an interesting study in progress a few days ago, during my visit to Cape Town, which prompted me to look up a paper that appeared earlier this year in the European Journal of Applied Physiology. It’s a case study of an elite Dutch cyclist being monitored with something called the Lamberts and Lambert Submaximal Cycle Test (LSCT), which was first described last year in a British Journal of Sports Medicine paper.

The gist is as follows: to warm up before a hard workout, you do a specific 15-minute protocol (6min at 60% of max heart rate, 6min at 80%, and 3min at 90%). You measure your power output and perceived exertion during these three stages, and then you measure how much your heart rate decreases during the 90 seconds after the test. Doing the test frequently (it’s not too strenuous, so you can do it as a warm-up before pretty much every workout) gives you objective data that tells you whether you’re fresh or tired, and whether your training is making you faster or slower.

Just as a sample, here’s a snippet of data, showing the power (at a fixed heart rate) for the first stage of the test, compared to the weekly training load. Pretty clear correlation:

lsctYou can see a gradual increase in power as the training cycle progresses, indicating that the cyclist is getting fitter. But you can also see big spikes in power during the heavy training weeks — that’s not because he was “fitter,” but because the acute training-induced fatigue meant he had to work harder (and thus produce more power) in order to get his heart rate up to 60% max. The mechanism has to do with decreased sympathetic nerve activity and increased parasympathetic nerve activity — and what’s most interesting to me is that the exact opposite happens in the case of chronic training-induced fatigue.

The same pattern can be seen in the heart rate recovery data:

lsct2During the heavy training weeks, the athlete’s heart dropped more quickly than during the other weeks. So he was tired from the dramatic increase in training load — but the test suggests that he was what the researchers call “functionally overreached” as opposed to “non-functionally overreached.” Had he persisted with the extreme training load for too long, his heart-rate recovery would have started to dip down instead of up, indicating overtraining. In other words, the researchers conclude:

This suggests that training-induced acute and chronic fatigue are reflected differently in the LSCT, which has important practical applications for monitoring.

Obviously this test is best suited to cycling, since you can precisely measure your power output. But I wonder whether a simplified version of the test, where you just exercise (run, row, whatever) at a set submaximal heart rate and then measure your heart rate recovery, would provide any meaningful information.

Oh yeah, the study I saw in progress: two groups of cyclists, each doing two (I think) hard workouts a week. One group does them on set days, come hell or high water; the other group does the LSCT three times a week, and determines whether or not to work out that day depending on the results. The hypothesis is that working out when your body is ready to go, and resting when it’s not, will lead to greater gains in fitness and performance. It’ll be interesting to see the results.