Last year saw the number of race places filled increase from 550 to 1,300.
"There has been a huge surge in interest," says John Lunn, Triathlon Scotland's development manager. "Young people are the real growth area for the sport and there are more events this year to try and accommodate that interest."
The Scottish Schools' Champ-ionships will take place alongside the Stirling Triathlon at Stirling University on June 2. It will be the first time the championships, in their third year, will be staged in Stirling after two successful years in Edinburgh.
"The Championship will be able to cater for 300 triathletes and we'll be doing well if we can get close to that," said Mr Lunn.