Neanderthals: They weren’t really into distance running. According to research by David Raichlen in the Journal of Human Evolution, they were more the power walking type: The shape of a Homo sapiens heel compared to that of a Neanderthal would have allowed our ancestors to be much more efficient runners over long distances.
Raichlen stated with living humans, studying them as they ran on treadmills.
By looking at MRI scans of their ankles, he found that the distance between a point on the heel bone just below the ankle bone, and the back of the heel bone where the Achilles tendon attaches, was proportional to the runner’s efficiency. The shorter this distance, the greater is the force applied to stretch the tendon – and the more energy is stored in it. This means that people with shorter distances are more efficient runners, using less energy to run for longer. [New Scientist]
With this knowledge, Raichlen and colleagues looked at the remains of Neanderthals as well as humans of the same era. The difference, he says, was distinct.
No, this ostrich is not decked out early for Halloween. The bird’s glowing get-up is part of an experiment that settled just why these elongated creatures can run so much faster and farther than us: They have twice as much bounce in their step.
Jonas Rubenson and colleagues adorned the tame ostriches with the reflectors at points that would show how their joints moved as they sprinted down a test track. The team watched the birds run and then sampled human volunteers the same way. Rubenson’s study appears in the Journal of the Royal Society Interface.
“Cheetahs and lions are great sprinters, but they use a lot of energy when moving,” he says. “However ostriches, horses and antelopes are adapted to running fast and economically over long distances.” Rubenson says previous work had shown the ostrich uses 50% less energy running when compared with humans, yet can run at twice the speed. [Australian Broadcasting Corporation]
About two-fifths of marathon runners “hit the wall” on the big day. That means they completely deplete their body’s stash of readily available energy, which makes them feel wiped out and severely limits their running pace; it sometimes forces people out of the run completely.
Marathoner and biomedical engineer Benjamin Rapoport has been physically and mentally struggling with this phenomenon for years, and had the bright idea to turn it into a research project. He published a mathematical theory in the journal PLoS Computational Biology describing how and why runners hit the wall–and how they can avoid it.
By taking into account the energy it takes to run a marathon, the body’s energy storage capacity and the runner’s power, the researchers were able to accurately calculate how many energy-rich carbohydrates a runner needed to eat before race day and how fast to run to complete all 26.2 miles (42 kilometers). [LiveScience]
Rapoport’s studies of marathoners were prompted by his desire to run in the Boston Marathon in 2005, and his teacher’s desire for him to be in class. In return for missing class, Rapoport was tasked with giving a class lecture on the physiology of the marathoner. That same year, Rapoport himself hit the wall while running the New York Marathon.
Perhaps the original design is still the best. In this week’s Nature, Harvard’s Daniel Lieberman and his team reported on the impact force of people who are used to running barefoot versus those of us who wear spongy sneakers to protect the bottoms of our feet. Those who ran barefoot (the way humans evolved to run) moved differently, and with far less stress on their feet than the shoe-wearing masses.
The researchers first traveled to Kenya to watch endurance runners who grew up running sans shoes. The study—the first to test lifelong barefoot runners and not simply people trying it out—found that the barefoot runners landed on the front or middle of their feet. By contrast, runners in shoes typically land on their heels. Lieberman says: “This creates an impact; it’s like someone hitting your heel with a hammer with up to three times your body weight” [BBC News]. In follow-up tests in the United States, the team noted that barefoot runners put, on average, only a third of the initial impact force on their feet than their shod counterparts did.
If you read this blog last week, you might have seen us cover a study suggesting that South African sprinter Oscar Pistorius ought to be allowed to compete in the same track and field events as everyone else because his prosthetic legs confer no advantage over a sprinter with biological legs. But if you saw a study cited by the Associated Press and many other publications yesterday, you might think that Pistorius would soon be banned from competitions, because his “blades” let him swing his legs far faster than even the world’s fastest man, Usain Bolt. So what the heck is going on?
The AP’s study isn’t actually a “study,” per se. Rather, what the Journal of Applied Physiology published was a point-counterpoint (pdf), now freely available for anyone to read. In in, Peter Weyand and Matthew Bundle argue that Pistorius’ prosthetics are a huge advantage, particularly in what matters most: how fast he can move his legs. Weyand and Bundle say that the lightweight blades allow Pistorius “to reposition his limbs 15.7 percent more rapidly than five of the most recent former world-record holders in the 100-meter dash” [AP].
There is, however, a counterpoint to this argument in the journal piece that yesterday’s news reports neglected, coauthored by Alena Grabowski of the MIT Media Lab (who led the research on Pistorius’ blades that 80beats covered last week). Her team has found that the limiting factor determining an athlete’s top speed was how hard the foot or prosthesis hit the ground. Their study showed this “ground force” was around 9% lower in the prosthetic limb versus the unaffected leg [The Guardian]. Grabowski’s research focused on professional runners with only one prosthetic leg.
South African sprinter Oscar Pistorius raised a ruckus last summer when the he wanted to qualify for the Beijing Olympics, thanks to the J-shaped carbon fiber blades that the double-amputee uses to run. Pistorius didn’t get to run in last summer’s games, but now an MIT team has released a study declaring that he doesn’t have an unfair advantage. Rather, the researchers found quite the opposite: Running blades for amputees, even made with today’s best materials, can’t compete with the legs that humans have evolved.
Pistorius has long argued that he should be allowed to compete alongside able-bodied athletes in races, but athletics authorities banned him from doing so in last year’s Olympic games, claiming that his blades gave him an unfair advantage over able-bodied athletes [The Guardian]. The MIT Media lab team led by Alena Grabowski helped to reverse his racing ban before turning its attention this year to the general question of whether blades or legs are better.
The team concocted a clever solution to the problem of testing this question. The study participants were six elite sprinters who had one intact leg and one leg that had been amputated below the knee. Researchers decided to study these types of amputees because they could compare their affected leg to their unaffected leg [Los Angeles Times].