Fast food

While illegal performance-enhancing drugs have destroyed the careers of sprinters such as Ben Johnson, the development of creatine, the naturally occurring protein, has been key in driving down race times. “It is perhaps the best-known aid to high-intensity athletic performance,” says Olympic gold medalist Darren Campbell. But it has really only been around since 1992, when guys like Linford Christie and Carl Lewis were among the first runners to use it.

Top gear

A sprinter’s equipment might be limited to singlet, shorts and shoes, but, “Every area of the sport has moved forward,” says Campbell, citing technological innovation, “from the reduction in the weight of the spikes they run in, to improved weights equipment that helps runners become more powerful.”

The height of success

“The past ten years has seen a trend towards taller, more slender sprinters,” says Dr Matthew Taylor, a sports scientist at Essex University. Dr Taylor’s research into the science behind Usain Bolt’s success helps explain the effects of this change in sprinters’ physiques. “When a sprinter is taller they take longer steps,” he says, “And if you are more slender and you have to carry less weight, your power-to-weight ratio improves.” 

On the right tracks

The 1968 Mexico City Olympics was the first Games to feature a hard, synthetic track, rather than the much softer cinder surface. “Sprinters need a hard surface, because that allows them to generate more force off the ground to propel themselves further forward,” says Campbell. There is good news for those hoping that the record falls again this year. “I’ve already walked on the London track and know it’s a quick one,” says Campbell.

One in a million

It is a slice of immense good fortune that an athlete such as Usain Bolt was even born. Dr Taylor says: “Sprinters by definition are not normal people, and Usain Bolt is not a normal sprinter. He is unique.” But even with Bolt on the starting line, a new record isn’t guaranteed. Campbell says: “Executing on the day when the eyes of the world are on you is what matters. You have to stay relaxed.”

Past and present athletes Bolt has pipped to the post

1. Usain Bolt - 9.69, Beijing 2008. Four years ago he won gold and broke the world record - despite having one shoe untied and starting to celebrate before reaching the finish line.

2. Donovan Bailey - 9.84, Atlanta 1996. The Canadian’s winning time remained an Olympic record for 12 years, before it was shattered by Usain Bolt in Beijing.

3. Ben Johnson - 9.79, Seoul 1988. The Canadian’s triumph was erased from the record books after he failed a drugs test. But even powered by steroids he still trails Bolt by metres.

4. Justin Gatlin - 9.85, Athens 2004. Following a four-year doping ban, the American has made an explosive comeback and will be a contender in London.

5. Maurice Greene - 9.87, Sydney 2000. The highlight of Greene’s injury-blighted career, but the American remains the world record holder over 60 metres.

6. Linford Christie - 9.96, Barcelona 1992. The third Brit to win the blue riband event. Aged 32, he is the oldest ever winner of the Olympic 100m.

7. Carl Lewis - 9.99, Los Angeles 1984. Just one of four golds the American won in Los Angeles, equalling the great Jesse Owens haul in Berlin in 1936.

8. Allan Wells - 10.25, Moscow 1980. A boycott by the US helped the flying Scotsman but, roared on by wife Margot, he grabbed the opportunity in style. 

See if Bolt can beat his own world record in the men’s 100m final - tonight at 9:50pm on BBC1, BBC Olympics 3.