Image caption Olympic timings need to be precise to cater for close finishes - as in Athens 2004, when America's Justin Gatlin beat Portugal's Francis Obikwelu by just 0.01s in the 100m final

Olympic timekeepers Omega are unveiling the latest technology that will be used at the London 2012 Games. It can monitor athletes' performance to the nearest one thousandth of a second. How does it work, and how can athletes make every instant count as they go for gold?

Timing at the Olympics has come a long way since a single technician with 27 stopwatches was sent to oversee proceedings at the Berlin Games in 1936.

In London this summer, there will be 450 professional timekeepers supported by about 800 trained volunteers, working with 420 tonnes of equipment including 390 scoreboards, 180km of cables and state-of-the-art timekeeping and data-handling technology.

At the Olympics, races with tight finishes can be won or lost by the width of a vest, so every element of timing is vital.

Perhaps the most scrutinised race at London 2012 will be the men's 100m final.

And the man with the responsibility for firing the gun at that race is Alan Bell, the Games' chief starter.

Blink of an eye

Mr Bell has witnessed major technological developments since he began officiating races in the 1980s, when most races were judged with orthodox pistols and hand-held timers.

"Race timing has come on light years since then," he told the BBC. And the days when athletes broke through a tape at the finish line - as they did the last time the Games were held in London, in 1948 - are long gone.

At London 2012, the starter's gun will be electronic and entirely integrated with a quantum timing system which will allow races to be timed to the nearest one thousandth of a second - 40 times quicker than the blink of an eye.

The fired gun sends an electrical current to the starting blocks - specially modified with pressure pads to detect false starts - which starts a quartz oscillator in the timing console.

'Top technology'

The sound of the shot is amplified through speakers on each set of blocks so all competitors hear it at the same time.

At the finish, a laser is projected across the line at a photoelectric cell or electric eye which, when crossed by an athlete, sends a signal to the timing console to record the runner's time.

This is synchronised with the reading of a high-speed digital video camera that can be used to decide a photo-finish.

Athlete's view - Milorad Cavic Image caption Touch pads are used in the pool to monitor when a swimmer completes a race In some longer disciplines, a swimmer can afford to glance at the clock while racing to pace themselves, but as a sprinter, it's just a bad idea. Technically we'd have to alter one or two strokes in a way so that we could look at the clock, and the cost-benefit for shorter distance races just doesn't make sense. We dedicate a good amount of time - three workouts per week - to focus on starts and finishes, with video analysis sometimes, but that's not to say we don't give them enough thought on a day-to-day basis. It's hard to work on the timing of the finishes because they vary depending on the position we're in in the pool and the fatigue our bodies experience at that very moment. In theory, touchpad timing is supposed to take away "human error" in making an accurate and unbiased measurement. In practice though, even the touchpad has its own flaws in sensitivity for example, to where the human eye can make a better assessment than technology. Serbia's Milorad Cavic won silver in the men's 100m butterfly at Beijing 2008 - losing to Team USA's Michael Phelps by the pressure of a finger-tip

Similar hi-tech systems are used in track cycling, with a radio transponder attached to the front tyre of each bicycle emitting an identification code to antennae placed at the start and finish lines.

In swimming, touch pads are used to record when a swimmer dives into the pool and when they touch the edge of the pool at the race's end.

A former athlete, Mr Bell has started some big races - not least Usain Bolt's world record 100m in Berlin 2010, and his disqualification in the 100m final at last year's world championships in South Korea - but to officiate an Olympics on home turf will be, he said, the pinnacle of an incredible career.

He said composure was key to starting a race, but would not be drawn into a discussion on the "one strike and you're out" false start ruling - saying only that it has, at least, kept athletics meetings on schedule.

A false start is triggered if an athlete leaves the starting blocks within 100/1000ths of a second of the gun being fired, and former mile and 1,500m world champion Steve Cram said the zero-tolerance ruling made reaction time even more important.

While starts and finishes were crucial for sprinters, they were also important for endurance runners, he added.

"The margins are tight - Kelly Holmes won the 800m in Athens by the thickness of a vest," Mr Cram told the BBC. "You can lose a 10,000m by 1/1,000th of a second as well as a 100m."

Going for gold

With all the technological developments, is it possible for modern athletes to beat the clock?

While analysts suggest not, they say there are tricks to maximise performance at the start and finish of a race.

Sports psychologist Dr Costas Karageorghis, author of Inside Sport Psychology and coach of British student athletes, said athletes were influenced by social elements, such as the size and density of the crowd.

Performing on home turf would lend an advantage to British athletes, he said, because crowd support would optimise their pre-event activation, increasing their psycho-motor arousal and essentially speeding their reaction times.

Dr Karageorghis advised athletes to study the pattern of the starter before the race, as any idiosyncrasies could help anticipate the gun and improve reaction time.

Image caption In track cycling events can be decided by the width of a tyre

Mr Bell, though, rejected the suggestion that athletes can learn from starters' idiosyncrasies, as no two races are the same. "Trying to predict when I'm going to pull the trigger is literally a non-starter," he quipped.

At the other end of the race, athletes could follow the example of British hurdler Colin Jackson in swooping for the finish line, said Dr Victor Thompson, a sports psychologist and international triathlete.

In the pool, finishing a race with an arm fully extended rather than tucked behind the body at the end of a stroke could make all the difference in a tight finish.

In training, swimmers mostly use tumble-turns at the end of a lap, gliding to the end of a pool at the end of a practice session, rather than pushing for an imaginary touch-pad, said sports psychologist Phil Johnson, who is training a Team GB would-be Olympian swimmer.

"In the fly, if you're getting close to touchpad and have completed your down movement you're having to make a decision to carry on momentum or start another stroke - which will lose you half a second," he told the BBC.

That half-second equates to crucial inches, which could make the difference between winning, or not winning, a gold medal.