Are athletes really getting faster, better, stronger? | David Epstein

6,965,430 views ・ 2014-04-29

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00:12
The Olympic motto is "Citius, Altius, Fortius."
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Faster, Higher, Stronger.
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And athletes have fulfilled that motto rapidly.
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The winner of the 2012 Olympic marathon
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ran two hours and eight minutes.
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Had he been racing against the winner
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of the 1904 Olympic marathon,
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he would have won by nearly an hour and a half.
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Now we all have this feeling
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that we're somehow just getting better
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as a human race, inexorably progressing,
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but it's not like we've evolved into a new species
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in a century.
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So what's going on here?
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I want to take a look at what's really behind
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this march of athletic progress.
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In 1936, Jesse Owens
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held the world record in the 100 meters.
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Had Jesse Owens been racing last year
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in the world championships of the 100 meters,
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when Jamaican sprinter Usain Bolt finished,
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Owens would have still had 14 feet to go.
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That's a lot in sprinter land.
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To give you a sense of how much it is,
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I want to share with you a demonstration
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conceived by sports scientist Ross Tucker.
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Now picture the stadium last year
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at the world championships of the 100 meters:
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thousands of fans waiting with baited breath
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to see Usain Bolt, the fastest man in history;
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flashbulbs popping as the nine fastest men in the world
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coil themselves into their blocks.
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And I want you to pretend
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that Jesse Owens is in that race.
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Now close your eyes for a second and picture the race.
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Bang! The gun goes off.
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An American sprinter jumps out to the front.
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Usain Bolt starts to catch him.
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Usain Bolt passes him, and as the runners come to the finish,
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you'll hear a beep as each man crosses the line.
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(Beeps)
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That's the entire finish of the race.
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You can open your eyes now.
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That first beep was Usain Bolt.
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That last beep was Jesse Owens.
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Listen to it again.
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(Beeps)
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When you think of it like that,
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it's not that big a difference, is it?
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And then consider that Usain Bolt started
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by propelling himself out of blocks
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down a specially fabricated carpet
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designed to allow him to travel
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as fast as humanly possible.
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Jesse Owens, on the other hand,
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ran on cinders, the ash from burnt wood,
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and that soft surface stole far more energy
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from his legs as he ran.
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Rather than blocks, Jesse Owens had a gardening trowel
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that he had to use to dig holes in the cinders to start from.
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Biomechanical analysis of the speed
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of Owens' joints shows that had been running
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on the same surface as Bolt,
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he wouldn't have been 14 feet behind,
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he would have been within one stride.
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Rather than the last beep,
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Owens would have been the second beep.
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Listen to it again.
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(Beeps)
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That's the difference track surface technology has made,
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and it's done it throughout the running world.
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Consider a longer event.
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In 1954, Sir Roger Bannister
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became the first man to run under four minutes in the mile.
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Nowadays, college kids do that every year.
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On rare occasions, a high school kid does it.
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As of the end of last year,
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1,314 men
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had run under four minutes in the mile,
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but like Jesse Owens,
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Sir Roger Bannister ran on soft cinders
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that stole far more energy from his legs
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than the synthetic tracks of today.
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So I consulted biomechanics experts
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to find out how much slower it is to run on cinders
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than synthetic tracks,
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and their consensus that it's one and a half percent slower.
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So if you apply a one and a half percent slowdown conversion
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to every man who ran his sub-four mile
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on a synthetic track,
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this is what happens.
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Only 530 are left.
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If you look at it from that perspective,
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fewer than ten new men per [year]
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have joined the sub-four mile club
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since Sir Roger Bannister.
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Now, 530 is a lot more than one,
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and that's partly because there are many more people
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training today and they're training more intelligently.
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Even college kids are professional in their training
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compared to Sir Roger Bannister,
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who trained for 45 minutes at a time
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while he ditched gynecology lectures in med school.
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And that guy who won the 1904 Olympic marathon
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in three in a half hours,
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that guy was drinking rat poison and brandy
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while he ran along the course.
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That was his idea of a performance-enhancing drug.
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(Laughter)
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Clearly, athletes have gotten more savvy
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about performance-enhancing drugs as well,
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and that's made a difference in some sports at some times,
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but technology has made a difference in all sports,
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from faster skis to lighter shoes.
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Take a look at the record for the 100-meter freestyle swim.
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The record is always trending downward,
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but it's punctuated by these steep cliffs.
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This first cliff, in 1956, is the introduction
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of the flip turn.
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Rather than stopping and turning around,
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athletes could somersault under the water
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and get going right away in the opposite direction.
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This second cliff, the introduction of gutters
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on the side of the pool
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that allows water to splash off,
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rather than becoming turbulence
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that impedes the swimmers as they race.
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This final cliff,
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the introduction of full-body
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and low-friction swimsuits.
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Throughout sports, technology has changed the face of performance.
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In 1972, Eddy Merckx set the record
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for the longest distance cycled in one hour
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at 30 miles, 3,774 feet.
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Now that record improved and improved
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as bicycles improved and became more aerodynamic
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all the way until 1996,
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when it was set at 35 miles, 1,531 feet,
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nearly five miles farther
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than Eddy Merckx cycled in 1972.
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But then in 2000, the International Cycling Union
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decreed that anyone who wanted to hold that record
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had to do so with essentially the same equipment
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that Eddy Merckx used in 1972.
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Where does the record stand today?
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30 miles, 4,657 feet,
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a grand total of 883 feet
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farther than Eddy Merckx cycled
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more than four decades ago.
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Essentially the entire improvement in this record
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was due to technology.
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Still, technology isn't the only thing pushing athletes forward.
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While indeed we haven't evolved
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into a new species in a century,
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the gene pool within competitive sports
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most certainly has changed.
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In the early half of the 20th century,
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physical education instructors and coaches
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had the idea that the average body type
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was the best for all athletic endeavors:
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medium height, medium weight, no matter the sport.
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And this showed in athletes' bodies.
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In the 1920s, the average elite high-jumper
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and average elite shot-putter were the same exact size.
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But as that idea started to fade away,
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as sports scientists and coaches realized that
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rather than the average body type,
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you want highly specialized bodies
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that fit into certain athletic niches,
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a form of artificial selection took place,
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a self-sorting for bodies that fit certain sports,
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and athletes' bodies became more different from one another.
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Today, rather than the same size as the average elite high jumper,
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the average elite shot-putter
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is two and a half inches taller
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and 130 pounds heavier.
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And this happened throughout the sports world.
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In fact, if you plot on a height versus mass graph
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one data point for each of two dozen sports
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in the first half of the 20th century, it looks like this.
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There's some dispersal,
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but it's kind of grouped around that average body type.
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Then that idea started to go away,
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and at the same time, digital technology --
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first radio, then television and the Internet --
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gave millions, or in some cases billions, of people
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a ticket to consume elite sports performance.
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The financial incentives and fame and glory afforded elite athletes skyrocketed,
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and it tipped toward the tiny upper echelon of performance.
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It accelerated the artificial selection for specialized bodies.
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And if you plot a data point for these same
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two dozen sports today, it looks like this.
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The athletes' bodies have gotten
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much more different from one another.
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And because this chart looks like the charts
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that show the expanding universe,
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with the galaxies flying away from one another,
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the scientists who discovered it call it
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"The Big Bang of Body Types."
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In sports where height is prized, like basketball,
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the tall athletes got taller.
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In 1983, the National Basketball Association
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signed a groundbreaking agreement
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making players partners in the league,
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entitled to shares of ticket revenues
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and television contracts.
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Suddenly, anybody who could be an NBA player
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wanted to be,
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and teams started scouring the globe
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for the bodies that could help them win championships.
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Almost overnight,
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the proportion of men in the NBA
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who are at least seven feet tall doubled
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to 10 percent.
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Today, one in 10 men in the NBA
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is at least seven feet tall,
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but a seven-foot-tall man is incredibly rare
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in the general population --
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so rare that if you know an American man
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between the ages of 20 and 40
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who is at least seven feet tall,
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there's a 17 percent chance
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he's in the NBA right now.
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(Laughter)
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That is, find six honest seven footers,
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one is in the NBA right now.
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And that's not the only way that NBA players' bodies are unique.
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This is Leonardo da Vinci's "Vitruvian Man,"
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the ideal proportions,
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with arm span equal to height.
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My arm span is exactly equal to my height.
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Yours is probably very nearly so.
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But not the average NBA player.
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The average NBA player is a shade under 6'7",
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with arms that are seven feet long.
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Not only are NBA players ridiculously tall,
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they are ludicrously long.
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Had Leonardo wanted to draw
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the Vitruvian NBA Player,
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he would have needed a rectangle and an ellipse,
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not a circle and a square.
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So in sports where large size is prized,
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the large athletes have gotten larger.
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Conversely, in sports where diminutive stature is an advantage,
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the small athletes got smaller.
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The average elite female gymnast
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shrunk from 5'3" to 4'9" on average
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over the last 30 years,
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all the better for their power-to-weight ratio
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and for spinning in the air.
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And while the large got larger
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and the small got smaller,
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the weird got weirder.
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The average length of the forearm
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of a water polo player in relation
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to their total arm got longer,
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all the better for a forceful throwing whip.
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And as the large got larger,
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small got smaller, and the weird weirder.
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In swimming, the ideal body type
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is a long torso and short legs.
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It's like the long hull of a canoe
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for speed over the water.
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And the opposite is advantageous in running.
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You want long legs and a short torso.
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And this shows in athletes' bodies today.
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Here you see Michael Phelps,
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the greatest swimmer in history,
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standing next to Hicham El Guerrouj,
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the world record holder in the mile.
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These men are seven inches different in height,
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but because of the body types
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advantaged in their sports,
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they wear the same length pants.
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Seven inches difference in height,
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these men have the same length legs.
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Now in some cases, the search for bodies
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that could push athletic performance forward
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ended up introducing into the competitive world
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populations of people that weren't previously competing at all,
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like Kenyan distance runners.
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We think of Kenyans as being great marathoners.
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Kenyans think of the Kalenjin tribe
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as being great marathoners.
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The Kalenjin make up just 12 percent
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of the Kenyan population
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but the vast majority of elite runners.
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And they happen, on average,
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to have a certain unique physiology:
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legs that are very long
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and very thin at their extremity,
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and this is because they have their ancestry
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at very low latitude
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in a very hot and dry climate,
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and an evolutionary adaptation to that
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is limbs that are very long
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and very thin at the extremity
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for cooling purposes.
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It's the same reason that a radiator has long coils,
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to increase surface area compared to volume
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to let heat out,
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and because the leg is like a pendulum,
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the longer and thinner it is at the extremity,
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the more energy-efficient it is to swing.
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To put Kalenjin running success in perspective,
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consider that 17 American men in history
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have run faster than two hours and 10 minutes
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in the marathon.
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That's a four-minute-and-58-second-per-mile pace.
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Thirty-two Kalenjin men did that last October.
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(Laughter)
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That's from a source population the size
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of metropolitan Atlanta.
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Still, even changing technology
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and the changing gene pool in sports
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don't account for all of the changes in performance.
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Athletes have a different mindset than they once did.
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Have you ever seen in a movie when someone gets
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an electrical shock
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and they're thrown across a room?
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There's no explosion there.
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What's happening when that happens is that
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the electrical impulse is causing
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all their muscle fibers to twitch at once,
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and they're throwing themselves across the room.
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They're essentially jumping.
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That's the power
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12:22
that's contained in the human body.
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12:24
But normally we can't access nearly all of it.
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12:26
Our brain acts as a limiter,
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12:28
preventing us from accessing all of our physical resources,
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because we might hurt ourselves,
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tearing tendons or ligaments.
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But the more we learn about how that limiter functions,
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the more we learn how we can push it back
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just a bit,
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in some cases by convincing the brain
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that the body won't be in mortal danger
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by pushing harder.
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Endurance and ultra-endurance sports
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serve as a great example.
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Ultra-endurance was once thought to be harmful
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to human health,
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but now we realize
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12:54
that we have all these traits
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12:55
that are perfect for ultra-endurance:
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12:58
no body fur and a glut of sweat glands
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13:01
that keep us cool while running;
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13:02
narrow waists and long legs compared to our frames;
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13:06
large surface area of joints for shock absorption.
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13:09
We have an arch in our foot that acts like a spring,
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13:12
short toes that are better for pushing off
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13:14
than for grasping tree limbs,
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13:15
and when we run,
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we can turn our torso and our shoulders
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13:18
like this while keeping our heads straight.
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13:20
Our primate cousins can't do that.
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13:21
They have to run like this.
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13:24
And we have big old butt muscles
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13:26
that keep us upright while running.
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13:28
Have you ever looked at an ape's butt?
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13:30
They have no buns because they don't run upright.
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13:33
And as athletes have realized
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13:34
that we're perfectly suited for ultra-endurance,
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13:37
they've taken on feats
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13:38
that would have been unthinkable before,
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13:40
athletes like Spanish endurance racer Kílian Jornet.
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13:44
Here's Kílian running up the Matterhorn.
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13:46
(Laughter)
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13:47
With a sweatshirt there tied around his waist.
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13:50
It's so steep he can't even run here.
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13:52
He's pulling up on a rope.
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13:53
This is a vertical ascent
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13:55
of more than 8,000 feet,
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13:57
and Kílian went up and down
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13:59
in under three hours.
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14:01
Amazing.
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14:03
And talented though he is,
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14:04
Kílian is not a physiological freak.
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14:07
Now that he has done this,
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14:09
other athletes will follow,
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just as other athletes followed
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14:12
after Sir Roger Bannister
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14:14
ran under four minutes in the mile.
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14:16
Changing technology, changing genes,
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1627
14:17
and a changing mindset.
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14:20
Innovation in sports,
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14:21
whether that's new track surfaces
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14:23
or new swimming techniques,
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1464
14:25
the democratization of sport,
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14:26
the spread to new bodies
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14:28
and to new populations around the world,
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14:30
and imagination in sport,
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14:32
an understanding of what the human body
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14:34
is truly capable of,
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14:36
have conspired to make athletes stronger,
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14:38
faster, bolder,
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14:40
and better than ever.
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14:42
Thank you very much.
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14:44
(Applause)
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