Some people may claim the sky's the limit but in the 15th Asian Games in Doha, Qatar, at least age is no barrier. A massive 55 years separates the youngest and oldest competitor, both of whom are also making their Asian Games debuts, demonstrating perfectly that age in sport is not a hurdle.
Iraq's Amer Ali who turned 10 on 31 August, is bravely competing in swimming. He was slowest in the heats in the 200m backstroke, but told poolside reporters that one day he hopes to win gold for his nation.
There is also no lack of ambition at the opposite end of the scale. Sixty-five-year-old Alan Puan Teik Chong of Singapore is taking part in cue sports, where he entered in billiards and is aiming for a medal.
Qatari schoolgirl Alaa Shoudy will turn 11 on 22 December and is excited at the prospect of making an impact in sailing at Doha. Shoudy is a remarkable sporting talent who has also represented her nation in gymnastics. But the more time she spent at the marina with her sailing- enthusiast father, the more she enjoyed it and eventually she decided to switch sports and follow in his wake.
Chong too is also keyed up and despite his advancing years is equally buoyant as the young sailor about Doha 2006. "It is my first Games, my biggest Games, and it could also be my last. But I will continue to compete as long as I feel fit. Billiards is mainly about skill. Age and stamina are not so important.
"I've never felt old at the table and I'm ready for a match with anyone, any age."
Chong reached the last 16 at the World Billiards Championships last year to prove his ability at the top level. He is also expected to contend strongly in the doubles, where he will partner former world champion Peter Gilchrist, who has no qualms over teaming up with the senior player. "He is still very fit, both mentally and physically and he puts in the same amount of training time as younger players." said Gilchrist, a Briton who took out Singaporean citizenship earlier this year.
Other competitors at Doha who find themselves at the extreme ends of the age spectrum are Chan Weng Sam of Macau of China and Emiko Nakagawa of Japan. Chan, just 13, finished 70th in the women's bowling.
Nakagawa, winner Japanese Championship in 1975, is taking part in the women's chess competitions. At 65, she is just 10 weeks younger than Chong.
Though the youngest and oldest participants always attract a certain amount of curious interest, don't be fooled into thinking they are merely making up the numbers. There are plenty of examples from Asian Games history to suggest that they can succeed, perhaps even win a medal.
Even in track and field, a sport where athletes are widely believed to be on the decline upon reaching 30, conventional wisdom has often been contradicted. At the 1998 Games in Bangkok, China's Li Meisu shrugged off her 39 years to win the shotput, 16 years after winning gold at the 1982 Games in New Delhi.
"I feel that in some events athletes retire too early," she said afterwards.
Doha 2006 has already seen another competitor pay little heed to regular thinking. Shooting is a sport where the cool head of experience is often seen to be a decisive factor.
In the men's 10m air rifle competition, 15- year-old Yu Jaechul of Malaysia caused a minor sensation when leading his country to team silver before going on to grab individual bronze. "I was not affected at all because I was not paying attention to the score," said Yu, hardly the words one would usually associate with the impetuosity of youth.
Yu was not supposed to succeed, but then neither was Li in 1998. Often the greatest figures in sport are those that do not do what they are supposed to do.
Kazakhstan's Dmitriy Gaag may be only a couple of months away from his 36th birthday, but that did not stop him running away from the rest of the field to win the first ever men's triathlon gold medal in Asian Games history in a time of 1 hour, 50 minutes 53.14 seconds.
Sport can do funny things to a man's life as well. In 1995, Dubai-based Roy Nasr took up triathlon as a way of getting fit. Eleven years later and he found himself taking part in the men's race at the 15th Asian Games at the age of 42.
He is Lebanon's only known triathlete; which also makes him the best. But unlike many of his opponents in Doha, he is not a full-time sportsman. He has a young family and a career to think about. For him the sport is a hobby.
"It's a bit overwhelming, just to see some of the other athletes who are half my age and so fit. I am the oldest entrant and the heaviest entrant and am ranked 29 out of 29 starters and can forget about a medal," Nasr said this week.
Working in a senior role in the airline industry, Nasr is competing as part of his annual leave. Indeed, he even had to return home after the opening ceremony for work requirements for a few days, before returning to the athletes' village.
But he was determined to make the most of his opportunity to represent his country. "For me, I wanted to walk with the Lebanese team and be part of the whole experience. I was hoping it would be spectacular and it really was. It was very special."
In the actual race, Roy's expectations were exceeded as he came home 24th out of 25 finishers in 2:17:03, 26 minutes adrift of gold medallist Gaag. Afterwards, he was breathless with fatigue and no little excitement at his venture onto the big stage.
They have the power within all of them to shock and amaze, change other people's mindset and dare to dream. And at times, it is the youngest and oldest that have the greatest incentive of all. Of all the competitors at the 15th Asian Games they, more than anyone else, can be the true history makers.