05 August 2012

Later Today: Fastest Human

The men's 100-m sprint final will be held later today.  The winner is often referred to as the world's fastest human.  Shelly-Ann Fraser-Pryce of Jamaica was crowned world's fastest woman yesterday as she edged my pre-Olympics pick, Carmelita Jeter of the US, by 0.03 s to take gold with a time of 10.75 s.  I was intrigued by Jeter's training after reading a Washington Post article last February that described how science and technology were helping shave tenths of a second off Jeter's 100-m time (click here for the article).  Jeter began training with John Smith about three years ago and made use of Ralph Mann's video analysis work at CompuSport.  Video of Jeter's sprints would be compared against a simulated sprinter racing with optimum technique.  Jeter was able to knock about 0.4 s off her personal best by making using of sports science.  Jeter had the best semifinal time of the London Olympics, and even improved on that by 0.05 s in the final, but Fraser-Pryce beat her own semifinal time by 0.10 s to win gold.

On the men's side, I made a bold prediction before the Olympics.  I claimed that the winner of the men's 100-m sprint would be Jamaican with an A in his first name and an L in his last name.  Okay, with current world-record holder Usain Bolt being joined by fellow countrymen Asafa Powell and Yohan Blake, my prediction was hardly the stuff of the clairvoyant!  What intrigues me about those three men is their height.  Bolt is 1.96 m (6' 5") tall; Powell is 1.91 m (6' 3") tall; Blake is 1.80 m (5' 11") tall.  Scaling arguments tell us that long legs are good for top speed, whereas short legs are good for acceleration.  If Blake makes the final, I'll be interested to see if he is able to get an early lead because of a possible acceleration advantage.  I'll then be interested to see if he can sustain a lead while longer-legged competitors possibly gain on him.

Making predictions for the 100-m sprint is difficult because there are so many factors at play.  One challenging aspect of the race for sprinters is the false start rule.  Two years ago, the IAAF (International Association of Athletics Federations) created the rule that a sprinter who pushes off the starting block less than 0.10 s after the gun goes off is disqualified.  There are no second chances!  Athletes risk disqualification if they try to anticipate the gun.  Starting blocks are electronically linked to the gun, meaning humans don't make disqualification decisions.  Usain Bolt was disqualified in last year's world championships after his false start.

Given the electronic linking of the blocks and guns, it is easy to determine athletes' reaction times.  Those times are typically in the range of 0.15 s - 0.20 s.  For a race that may be decided by hundredths of a second, reaction time could make all the difference between saluting one's flag from the medal stand and going home empty.

Once the race begins, note that sprinters are not completely upright as they accelerate out of the blocks.  They do not reach top speed until they've traveled a distance of 50 m - 60 m.  Being completely upright at top speed, the real skill in the final portion of the sprint is maintaining top speed.  Much of a sprinter's training focuses on the ability to hold off on slowing down for as long as possible.  Powerful muscles help supply energy at a sufficient rate to help top sprinters maintain top speed.  Those guys are not ripped for looks alone!

Being from the US, my rooting interests lie wih Ryan Bailey (height:  1.93 m or 6' 4"), Justin Gatlin (height:  1.83 m or 6' 0"), and Tyson Gay (height:  1.80 m or 5' 11").  When you watch the final of the 100-m sprint, look for the athlete that gets out of his blocks first.  Then, look to see if one of the shorter athletes (perhaps Blake, Gatlin, or Gay) is able to accelerate to the early lead.  Finally, take notice of top speeds and who is best able to sustain his top speed.  Will one of the taller athletes (perhaps Bolt, Powell, or Bailey) sustain the greatest top speed?

I'll write more on scaling arguments and different body types before the men's high jump final on Tuesday.

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