Competitors at this year s race obviously haven t reached the start line yet, but already records have been broken.

About 4,500 entries have been received for the event, smashing last year s total of 2,900, ensuring Blenheim is again the second largest event of its kind in the UK.

Event director Nick Rusling said: "Entries flooded in and we knew from early in the year that we were well on the way to seeing more than 4,000 athletes take part.

"At the start of March we had 1,300 more entries than the same time last year, so we have been thrilled with the figures.

This year s race promises to be bigger and better than ever before." Mr Rusling said the record entry levels had not come as a surprise to him and his team. "Triathlon really is enjoying a boom in the UK. It is one of the fastest-growing sports around, so we are not surprised that Blenheim has proven so popular.

"It is great to think we will soon be seeing more than 4,000 newcomers and experienced athletes swim, bike and run their way through the spectacular grounds of Blenheim Palace.

"Blenheim is a great event for first-timers to get involved in. It is one of the most scenic races in the country and there is always a great buzz on race day."

RACING on their own doorstep will be athletes from the city s triathlon club Oxford Tri.

It will have about 40 triathletes racing at Blenheim, ranging from world championship medallists through to first-timers.

The club, which has about 150 members, was founded 20 years ago when triathlon was still in its infancy.

It continues to attract athletes of all abilities and last year had three athletes finish in the top ten in their respective age groups at the World Championships in Lausanne, Switzerland.

Oxford Tri is hoping to repeat the successes from Blenheim 2006, when Sophie Whitwort finished fourth in the women s elite race, Emma-Kate Lidbury came second in the women s open race and Gavin Lumb, club captain Jerry Greatorex and Mark Herd all achieved a top 50 placing in the men s open race.

Jerry said: "Blenheim has something to offer all of our triathletes - the safe, traffic-free course is ideal for the beginners, yet hilly and challenging enough to keep the experienced athletes interested, and the fact that it all takes place in such a grand, picturesque setting gets everybody excited.

"There is no doubt that the event helps the club thrive. It attracts lots of local people t the club who are keen to gain the experience and fitness needed to compete in the event. We are hoping for another enjoyable and successful year." Although the triathlon season typically runs from May through to September, the majority of the Oxford Tri members train year-round, with swimming sessions held twice a week in the pool and twice a week in the lake in the summer.

Training rides, ranging in distance from 30 to 60 miles, take place at weekends and run sessions are held throughout the week.

For more information about the club, visit the website: www. oxfordtri. co. u k