The roots of endurance racing involving swimming, cycling and running can be traced to southern California, where the first triathlon was held in 1974. The sport has grown quickly: the first official world triathlon championships were held in 1989 and it made its Olympic debut in 2000.

However, just a few years ago, it was still the preserve of only a small clique of athletes. Now many of Scotland’s top races are oversubscribed at senior level and a look at Triathlon Scotland’s website shows the fixture list is becoming increasingly crowded. Triathlons have grown in popularity so much that races are even attracting so-called fun runners.

The sport is catering for schoolchildren too. This summer, the inaugural Scottish Schools Triathlon Championships were held at Holyrood Park and the Royal Commonwealth Pool in Edinburgh, attracting more than 70 entrants, some as young as eight, and there is confidence this will become an annual event.

The June event is believed to have been the first national schools competition in Britain: there is no national competition for English schools at present, although there is a National Youth Triathlon Championships, which will be hold at Eton on Sunday and feature Scottish competitors.

The Edinburgh event was held in conjunction with the Edinburgh Triathletes.

In the 8-12 years age bracket, children had to swim 150m, cycle 5km and finish with a 1.5km run. The 13 to 16-year-olds had to swim 350m, cycle 10km and run 2.5km. (The official distances for adults are set at 1,500m, 40km and 10km.) Caroline Wallace, a peripatetic primary physical education teacher in the Scottish Borders, doubles as Triathlon Scotland’s youth coach. She knows there may be some raised eyebrows at children as young as eight taking part in a triathlon but believes that there is a lot of untapped athletic potential in schools.

“We were just dipping our toe in the water with the schools championship but we received a very good entry with over 70 triathletes from across the country taking part,” Miss Wallace says.

“Many children have seen triathlons on television and the fact that Great Britain has a number of top-class triathletes who are doing well in international races has helped.

“We have gone into a number of primary schools now and the response from children has been excellent. A lot of schools have access to swimming pools and the children seem to enjoy having a shot at different disciplines.”

Children compete on closed roads and run on grass or tarmac, she explains.

For the younger age group, the emphasis is on enjoyment and no one is expecting much in a competitive sense. Schools have held events where eight-year-olds were still using stabilisers on their bicycles or have had to be pushed around. “The most important thing is for them to get some fun out of it,” she says.

Aquathons - which feature just swimming and running - have also sprung up in different parts of the country in recent years and this has provided a stepping stone towards triathlon for children.

“We get children from swimming clubs who may have become a bit bored with going to a meet and only being in the water for a minute or so. This gives them a chance to be involved for a longer period of time,” Miss Wallace expands. “We also get children coming to us from running clubs, but not so many from cycling clubs.”

Many of the competitors at the schools championships will also be competing in the Scottish Youth Triathlon Championships in Galashiels on September 20 and the Aquathon Series final at Portobello on September 28.

National Lottery funding means there are opportunities for schools athletes to progress to professional level. Scotland currently has 20 full-time triathletes.

Darren Smith, an Australian, has been Scotland’s national triathlon coach for three years. His first priority was to build a strong foundation to support his future elite programme.

“We now have part-time youth, junior and under-23 coaches and we have to have a strong foundation to build on,” he says. “If you don’t have children coming through, then there is nothing for the future. I want to see hundreds involved.

“The aquathon circuit is important as it gets children involved. There can be a tendency for children to become a little bored with just one sport by the time they reach 14 or 15 and this gives them a chance to try another.

“If they are good swimmers and not such good runners, or vice-versa, then they can work on their weaker sport and build that up over a series of races.

“People now understand that you don’t need to do 20 hours a week training to complete a triathlon. It has become a family race in Australia, where it is popular because of the environment, and it is growing in popularity here, with families now taking part in races.

“We are also doing well at elite level. At the last British championships in Swansea, Scotland had six of the top 15 in the men’s race and two of the top 12 in the women’s event. That is pretty good from a country a tenth of the size of England.”

Results: 8 years: 1 Mark Stewart; 2 Kate McCulloch-Young; 9-10 years: Angus Inwood; 2 Paul Stewart; 11-12 years: 1 Ben McCulloch-Young; 2 Craig McBride; 13-14 years: 1 Ian McBride; 2 Adam Wilson; 15-16 years: 1 Rory Methven; 2 Hatty Floydwww.tri-scotland.org