Abloiu09
Joined: 11 Dec 17 Posts: 15
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Posted: Thu Dec 14, 2017 12:52 am Post subject: Nike runners have scored some major victories in the shoe |
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chaussure nike femme soldes "The energetic savings at all three speeds was very consistent," says biomechanist Wouter Hoogkamer, who led the study. "We didn't test it at slower speeds, so it will be very interesting to do follow-up studies, but the consistency suggests the improvement to running economy will be similar whether the person wearing them is running a five minute mile or a 10 minute mile." The attribute the shoe's effectiveness not to its weight, but its unique materials. (At 199 grams, the size 10 Vaporfly prototype that the tested weighed four grams less than the Streak 6 and 51 grams less than the Boost 2, but Hoogkamer equalized their weight by sewing lead pellets into the tongues of both Nikes.)
chaussure nike hommme soldes The Vaporfly uses a very light, compressible, and—most importantly—springy foam. When the imulated the impact of a runner's footfall by pressing the shoes into a force-sensing plate, they found that the foam in the Vaporfly returned 87 percent of the energy it stored on impact. The Boost 2 returned 76 percent. The Streak 6? A measly 66 percent. The Vaporfly also features a carbon fiber plate in its midsole, which caused no shortage of controversy when Nike unveiled the shoe earlier this year. Any device inserted into the shoe, and which purports to add to energy return or elastic recoil or stiffness should be banned.
chaussure nike femme pas cher But at the time of the Vaporfly study, none of the test subjects knew that Nike's prototype was purported to improve running economy. (It's worth pointing out, too, that Nike's prototype looked pretty janky compared to the completed product the company now sells.) More importantly, MacIntosh says, it's very hard to lower your running economy intentionally. "The issue is: Even if the test subjects did know the shoe was supposed to improve running efficiency, how in the world could they alter their economy by 4 percent?" When I ask Kram why the test subjects were not blinded to the shoes they would be wearing.
chaussure nike hommme pas cher The bigger question now is: Why haven't the results from the study translated to actual road races? A 4 percent boost in running economy means that a marathoner usually capable of running a 2:05 race should be able to slip on a pair of Nike's shoes and run pretty close to a two hour race, no problem. But that’s not what we see in the real world. It's true, Nike runners have scored some major victories in the shoe—including Shalane Flanagan, who earlier this month became the first American woman to win the New York City Marathon since 1977—but none of the performances have been Earth-shattering. |
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