Meet the coaches behind the world's best Olympic teams
It is athletes who win medals, become famous in the media and sign lucrative endorsement deals.
But behind those superstars are the coaches who plan their programmes and put them on the way to success.
Here are some prime examples from the London 2012 Olympics:
Glen Mills (Jamaica)
Mills is the former Jamaica head coach who now runs the Racers Track Club in Kingston, where he trains elite sprinters like Usain Bolt, Yohan Blake and Warren Weir. That means Mills, 63, had a hand in five of the six medals won in the men's sprints at the London Olympics.
Bolt has identified what makes Mills special as a mentor: "There's times when you want to doubt yourself," he admits.
"But coach is always there to say, 'Don't worry, I know what I can do to make you run faster, and what you need to do to go faster.'"
Mills's runners won all of the individual sprint golds in London, finishing off in style when Jamaica smashed the world record in the 4x100m relay final.
Gregg Troy (USA)
Troy, 61, only took over as head coach of USA's swimming team for London, but in his 13 years in the same role for the University of Florida, he coached more than 75 Olympians and helped athletes to more than 150 US and international records.
An assistant coach to the US Olympic teams in Atlanta and Beijing, Troy's first spell as head coach secured 16 of the 34 gold medals on offer in the pool for the US in London. Their total of 31 medals was more than three times that of the second most successful nation, China.
In June, multiple medallist Ryan Lochte credited Troy's tough training routines for preparing him to qualify for the Olympic team. Troy trained several of the men and women who would eventually go on to swim for Team USA and is said to have told Lochte he had to train harder because he wasn't a 'natural' in the pool.
Gogi Koguashvili (Russia)
In London, Russian wrestlers once again dominated the medals with four gold medals, two silver and five bronze - replicating their result from Beijing.
Under Koguashvili, the nation's Greco-Roman squad again dominated. Russia's men won only one freestyle gold, but the upside was the emergence of their women - including new Olympic champion Natalia Vorobieva.
Many experts attribute the success to Yuri Shakhmuradov, the former men's coach who is now in charge of the women's programme. The 1970 world champion is Armenian by nationality and also director of the Olympic centre in Dagestan.
A national programme - "Fight and win!" - was launched in Russia before the Beijing Olympics. It was a new approach to solving urgent problems - not only sports-related but also social.
The development of wrestling in the North Caucasus republics is a "social elevator" for young people after years of conflict in the region. In general, that part of Eurasia produces the world's best wrestling talent, as the results of Iran, Georgia, Azerbaijan and Uzbekistan prove.
Dave Brailsford (GB)
Brailsford has been British Cycling's performance director for the last three Olympics, which means he has presided over teams that have won 30 medals, including 18 golds. The majority of those have come from track cycling, but he is also in charge of the BMX, mountain bike and road cycling programmes.
He also runs the Sky road cycling team, in whose colours Bradley Wiggins became Britain's first Tour de France champion last month. Throw in his masterminding of Mark Cavendish's 2011 world road race title and it is clear he is currently the most successful administrator working in British sport.
Brailsford, 48, is that rare mix of a "details guy" with a clear strategic vision. The sport was already on the up when he took over, but it was he who elevated British Cycling to superpower status.
He has proved himself able to get the best out of such diverse characters as Wiggins, Sir Chris Hoy and Victoria Pendelton.
He prefers to call himself "a conductor of the orchestra" these days but, if as expected, he takes a step back from Team GB to spend more time with Team Sky, he will be missed.
Jihong Zhou (China)
Zhou - known as the "flying swallow" - won platform gold in Los Angeles in 1984 and, after she retired two years later, she moved through the coaching ranks - perfecting a system that has seen China dominate diving for the best part of two decades.
China won seven of eight diving golds in Beijing and London saw them hold on to six of those titles.
"China have always been dominant, ever since I was diving they have always been the top nation," said BBC commentator and Olympic silver medallist Leon Taylor.
"Zhou heads up a system which, whether you agree with it or not, is tried and tested. They focus on athletes from a very young age and it delivers the results, but there are hundreds and thousands who don't make it."