Is athlete prowess attained or innate? Those who have suffered the scolding of a tyrannical games master at school might be forgiven for doubting the idea that anyone and everyone is capable of great sporting achievement, if only they would put enough effort into it. Practice may make perfect, but not all are built in ways that make it worth bothering in the first place. The latest evidence of this truth has been gathered by Sabrina Lee of Simon Fraser University in Vancouver and Stephen Piazza at Pennsylvania State University. They have looked at the anatomy of sprinters and found that their feet are built differently from those of couch potatoes. They looked at seven university splinters who specialize in the 100-metre dash and five 200-metre specialists, and compared them with 12 non-athletic university students of the same height. In particular, they looked at the sizes of bones of the toes and heel. They also used ultrasonic scanning to measure the sliding motion of the Achilles tendons(the tendon inside the back of your leg just above your heel)of their volunteers as their feet moved up and down. This allowed them to study the length of the lever created by the tendon as it pulls on the back of the heel to make the foot bend and push off the ground. Dr Lee and Dr Piazza found that the toes of their sprinters averaged 8.2cm in length, while those of non-sprinters averaged 7.3cm. The length of the lever of bone that the Achilles tendon pulls on also differed, being a quarter shorter in sprinters. These findings suggest sprinters get better contact with the ground by having longer toes. That makes sense, as it creates a firmer platform to push against. In a sprint race, acceleration off the block is everything. The reason for the difference in the Achilles tendons, though, is less immediately obvious. At first sight, sprinters might be expected to have more Achilles leverage than average, not less. First sight, however, is wrong. When muscles have to contract a long way, they usually do so quickly and with little force. When contracting short distances, though, they move more slowly and generate more force. Having a short Achilles lever allows the muscles that pull on the tendon to generate as much as 40% more force than the same muscles in a non-sprinter would be able to manage. It is possible—just—that these anatomical differences are the result of long and rigorous training., But it is unlikely. Far more probable is that the old saying of coaches, that great sprinters are born not made, is true. Everyone else, games masters included, should just get used to the idea.

单选题 According to Paragraph 1, the idea that practice makes perfect

单选题 Dr Lee and Dr Piazza found that the feet of the sprinters are different from those of

单选题 Longer toes of a sprinter are helpful in that they enable him to

单选题 We can learn from this text that the advantages of a sprinter come from

单选题 Which of the following best summarizes the text?