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Usain Bolt is one of—if not the—fastest men who has ever lived. At age 12 he was already the fastest boy in his school (Irving, 2010: 54). At the 2009 Berlin Olympics, he set the world record for 100 m race (Bolt also holds the world record for the 200 m dash, at 19.19s), clocking in at 9.58 seconds. His average speed was 27.8 mph with an average speed of 23.5 mph. Why is Bolt so fast? Of course, there are multiple interacting factors that contribute to Bolt’s world record times. Bolt’s somatotype, muscle fibers, will to win, intense training, mind, etc all contribute to his world record—along with the type of athlete he is. In this article I will discuss what Bolt does, his anatomy and physiology, what lead up to his record-breaking time, and a possible challenge to his record.

Usain Bolt is tall, as far as sprinters go, with a height of 6’5”. Since he is so tall, compared to other sprinters, his average stride length is at the extreme upper-limit of modern sprinters. So what makes Bolt unique as a sprinter is his stride length (Shinabarger, Hellrich, and Baker, 2010). So Bolt has to take fewer strides than other sprinters, which, in part, explains his success.

During Bolt’s record-setting 9.69 s dash in 2008, during the last 2 seconds—when 20 meters were left to run—Bolt looked to the side and started celebrating (Eriksen et al, 2009). Bolt’s coach claimed that he would have shattered even his future record-setting performance of 9.58 s running 9.52 s or better. The runner-up of this race was Richard Thompson. By 4 s, Bolt and Thompson were neck-and-neck, so Bolt’s medal was won between 4 and 8 s. After 8 s, Bolt considerably decelerated while Thompson equalizes and surpasses Bolt. Thompson could not match Bolt’s speed, though, and slows down after 8.5 s. Then, to answer the question “How fast would Bolt have run had he not celebrated the last 2 s?”, Eriksen et al (2009: 226) make two assumptions:

Assumption 1: Bolt matches Thompson’s speed at up to 8 s.
Assumption 2: Bolt maintains a 0.5 m/s2 higher acceleration than Thompson at 8.5 s.

Of course the justification for A1 is obvious: Bolt outran Thompson between 4 and 8 s. But in regard to A2, it is difficult to quantify exactly how much stronger Bolt was than Thompson, since Bolt is a 200m specialist, they take the 0.5 m/s2. So, in two scenarios that Eriksen et al (2009) put forth, the world record would either be 9.61 s or 9.55 s. Eriksen et al (2009: 228) conclude “that a new world record of less than 9.5 s is within reach by Usain Bolt in the near future.” And what do you know: a year later, Bolt ran the 100 m at 9.59 s.

Bolt has a slow reaction to the gun—that is, he has more moving to do to get to the sprinting start since he is so tall. His reaction time at the Beijing Olympic Final was 0.165 s. So if he could reduce his reaction to the gun by .3 s then he would have beaten his world record of 9.58 s to 9.56 s. If he could get it down to 0.12 s then he would be looking at a 9.55 s time, and if he could get it down to as fast as the rules allow—at 0.10 s—then his time would have been 9.53 seconds, almost right there by his coach’s prediction had he not celebrated during his record-setting run (Darrow, 2012).

Since Bolt is so tall—taller than his competitors—he can take fewer steps per 100 m. For instance, he set his record time in 2009 taking 41 steps to win, whereas his competitors took 45 steps (Beneke and Taylor, 2010). The average sprinter has a higher proportion of type II fibers compares to type I fibers (Zierath and Hawley, 2004). So one thing that separates Bolt from his contemporaries is superior biomechanical efficiency along with relative power generated per-step (Beneke and Taylor, 2010; Coh et al, 2018). So Bolt’s record-setting performances comes down to anthropometric characters, coordinated motor abilities, his ability to generate power, and an effective running technique. Sprint performance on the force generated during ground contact.

Bolt has an ectomorphic-dominant somatotype. Since he is ecto-dominant, this gives him certain advantages over more endo- and meso-dominant competitors. Furthermore, along with his body type, Bolt is Jamaican. Most of the ancestry found in Jamaicans is derived from West Africa. Jamaicans are more likely to have the RR ACTN3 genotype (Scott et al, 2010), while the RR genotype—along with type II fibers (with a greater cross-section area) contributes to whole muscle performance during high-velocity contractions (Broos et al, 2016). I am not aware of any analyses of Bolt’s genotype, but I would bet what’s in my bank account that he has the RR genotype—that he has two copies of ACTN3.

Tyson Gay then emerged as a challenger to Bolt (in 2013, Gay gave a dirty urine for PEDs, performance-enhancing drugs, and Bolt said that Gay should be “kicked out of the sport“). Varlet et al (2015) state that Bolt and Gay influenced how fast the other ran in Berlin, 2009. Both Bolt’s and Gay’s steps were pretty much synchronized with each other. Though since Gay was slightly behind Bolt in the race, he had the better chance to synchronize his movement with Bolt’s. However, Blikslager and de Poel (2017) argue against this: they state that there is no sufficient evidence for the claim that Bolt and Gay had synchronized movements.

The center of mass in blacks is around 3 percent higher in blacks than it is in whites. This 3 percent difference in center of mass between whites and blacks leads to them doing better in one sport over another: sprinting for blacks and swimming for whites (this is one reason why blacks are worse swimmers than whites). Further, for runners, the 3 percent increase in center of height translates over to a 1.5 percent increase in running speed, translating to a difference of 10 s compared to 9.85 s (Bejan, Jones, and Charles, 2010). So the change is 0.15 s for runners. This is yet another reason why Bolt excels: he is exceptionally tall.

Bolt is really tall compared to his contemporaries; Bolt goes through insane training (as do his contemporaries). Of course, the explanation for Bolt’s running success is due to numerous factors, including (but not limited to) his height, leg length/stride length, running economy, Vo2 max, training, where he grew up, and a whole slew of other—irreducible—factors. The fact that Bolt could have set an even more unbelievable record had he not celebrated with 2 s—or 20 meters—left during his record-setting run is incredible. That he can even hit at or near to what his coach predicted that he would have gotten had he not celebrated, while getting his reaction time better is even more incredible. Bolt does not even need to improve his running skill to become better—just improve his reaction to the gun and he will, in my opinion—set records that no one wull ever break.