Sport for ironmen and women is booming

As the triathlon season starts next month, figures from the British Triathlon Association show a huge increase in the popularity of swimming, cycling and running in a single event. It is as much to do with those seeking a open-air challenge away from the gym as the traditional "Ironmen" pushing their bodies to the limit.

Entries to triathlons have tripled to 100,000 in the past five years and membership of the British Triathlon Association (BTA) has doubled in the same period to 7,500. The number of events in the triathlon calendar has also doubled since 2000.

According to Norman Brook, the chief executive of the BTA, triathlon has grown in popularity since it became an Olympic sport at the 2000 Sydney Games. In common with every mass participation sport, it needs to be sustained by role models and Britain is one of the foremost nations in the sport with 15 triathletes among the world's top 50, including Tim Don, who came fourth in the recent Commonwealth Games in Melbourne, and the leading woman Andrea Whitcombe, ranked sixth in the world.

The sport's senior figures are also proud of its inclusiveness - as well as embracing the notorious Hawaii Triathlon, the Ironman world championship - there are triathlons held indoors and competitions dedicated to disabled athletes and children. One-third of all triathlon fields are women and in a drive to keep women in the sport a spate of women-only events, such as Chester's Deva Divas and the new Timex triathlon in Eton, have evolved.

"What you have to remember is that the sport is very flexible and not just about the iron-man long-distance triathlon taking up to 12 hours," said Mr Brook. "It's an extension of the long-distance running of the 1980s, which was a knock-on from the US boom. People who get involved are looking for a new challenge. A lot of people fall into it. They are doing marathons and cycle for fitness, or they go to the local gym and are looking for a new challenge.

"Triathlon is proving most popular among those aged 30 to 40, partly because it is those people who find they can't play team sports any more," he added. Unlike swimming and athletics, which are crudely divided between the main field and masters, triathlon is divided into five-year age bands. "It is organised into age bands so you can continue to have success and even if you are 44 you represent Britain. Getting older doesn't matter."

For the elite classes it can be expensive, with racing bikes costing several thousand pounds, a wetsuit and race fee of £60. But in the intermediate sections many ride on hybrid bikes and hire their wetsuits.

Triathlon is thought to have its roots in a race in France in the Twenties called "Les trois sports" and was reinvented in the Seventies in California.

In most modern triathlons, these events are placed back to back in immediate sequence and a competitor's official time includes the time required to "transition" between the individual legs of the race, including any time necessary for changing clothes and shoes. Proficiency in swimming, running and cycling alone is not sufficient to guarantee a triathlete a competitive time: trained triathletes have learned to race each stage in a way that preserves their energy and endurance for subsequent stages.