Tired brains, sprint supplements, and tunes that make you faster

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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 July-August issue of Canadian Running is on newsstands now, which means the latest “Science of Running” column is available online. Topics covered: why mental fatigue can slow you down as much as physical fatigue; how a supplement called beta-alanine can boost your sprint finish even at the end of a long race; how running compares to cycling and weight-lifting for building bone strength; what types of music boost performance; and the best pacing strategies for racing in the heat.

Of course, there’s lots of other good stuff in the issue, including (pardon the self-promotion) a feature I wrote on how running has influenced human evolution, and what it means for our current attempts to avoid injury. To whet your appetite, here are the first few paragraphs:

The giant screen at the front of the lecture theatre shows, in gruesome detail, a dissected bare foot connected through tendons to ten different muscles in the lower leg, all pulling in slightly different directions. Benno Nigg, a renowned professor of biomechanics who co-directs the University of Calgary’s Human Performance Laboratory, is leading an audience of Australian academics gathered at the University of Sydney through a presentation titled “The Future of Footwear.” During almost four decades as one of the world’s leading athletic shoe researchers, Nigg has worked closely with major companies such as Adidas, Nike and Mizuno. But plotting the future of the running shoe, he now believes, may require a look to the past, at what worked for our ancestors.

“Look at all these muscles here,” he says, gesturing at the dissected ankle. He asks the audience to guess which of the muscles we need in order to walk while wearing a typical shoe. Only two of the ten are needed, it turns out: the tibialis anterior (shin) and the triceps surae (calf). “And all the other ones, you don’t need, because the shoes take over.” Nigg pauses to let his audience consider this piece of trivia, then poses the central question of his talk: “Is that a problem?”

There are, of course, very good reasons for the existence of all the long, spring-like tendons and muscles in our legs. With each stride, we store energy in these coiled springs and then release it with the next stride – a process that researchers estimate saves about 50 percent of the energy we would otherwise require to run. This is one of the key observations made by Dennis Bramble of the University of Utah and Daniel Lieberman of Harvard University in a controversial 2004 cover story in the scientific journal Nature. Bramble and Lieberman enumerated 26 distinct features of the modern human skeleton that make our lives as runners much more pleasant, from the specialized neck tendon that keeps our head from flopping when we run to the unusually short toes that add stability and turn our legs into more efficient levers.

Bramble and Lieberman’s ER (for “endurance running”) hypothesis argues that running, rather than walking, was the crucial skill that separated us from our tree-borne simian cousins. Loping for long distances across the savannah allowed us to scavenge for meat from leftover kills and perhaps even chase live animals to exhaustion, and the demands of that pursuit shaped our subsequent evolution. The theory remains hotly disputed, though it has received widespread attention – especially from runners, who delight in newfound kinship with their post-Australopithecene forebears and vindication of their not-so-odd-after-all hobby. But from a runner’s point of view, it also leaves a puzzling question unanswered – one that Benno Nigg has been considering throughout his career. By some estimates, in any given year 70 to 80 percent of active runners will suffer a running injury. So if we were born to run, why are our bodies constantly breaking down?