Top triathletes from Rutland will be among the 1,000 entries competing in the Dambuster Race centred on Rutland Water on Saturday.
The three stage race, which begins with a 1.5km swim in Whitwell Creek and includes a 42 km bike ride and a 9.7km run before finishing at the reservoir’s dam, is the second round of the 2013 Triathlon England National Championships.
The race is also a world championship qualifying and European championship qualifying race.
Mark Shaw, of race organiser Pace Setter Events, said: “The event sold out in record time this year.
“The combination that the race is in the National Triathlon Championships for the first time, and a qualifier for the World Championships in London, has increased the profile and led to more excitement ahead of the race.”
Rutland’s first competitor to cross the finish line last year was Oakham’s Will Kirstein.
Running for Stamford Triathlon Club, he was 31st overall with a time of 2h00m29s. Michelle Wright, also from Oakham, was fifth lady overall with a time of 2.10.01.
Kirstein is due to line up again on Saturday.
Other Rutland-based triathletes registered to race include Luke Appleton, Robin Brookes, Roger Canham, Giles Cooper, Paul Cowling, Ross Dennison, Michael Fitzpatrick, Nick Greenwood, Gareth Hughes, David John, Nick Jones, Alex Knott, Martin MacDuff, Victoria Player, Mark Player, Kerry Rough, Andy Seaton, Jonathan Taylor, Stephen Tee and Liz Walne.