The number of athletes training at Allianz Park has increased by more than 50 per cent since the renovation of the stadium.

Thriving legacy projects may be hard to find in the city that hosted the Olympic Games just 18 months ago.

However, the £24million invested by Saracens shareholders – with no public funding – has created sporting opportunities for tens of thousands of people in north London.

Chairman Nigel Wray said: “Saracens is not the only club to make its home at Allianz Park.

“Shaftesbury Barnet Harriers are one of the most successful athletics clubs in the country, and we are delighted to have them as long-term partners at the new stadium.

“The extraordinary increase in numbers of athletes using the indoor and outdoor facilities is fantastic news.”

A total of 3,677 athletes trained at Allianz Park between October and November in 2013, compared to 2,442 between October and November in 2012 – an increase of 50.6 per cent.

Shaftesbury Barnet Harriers team manager Geoff Morphitis said: “The growth is fantastic, and our club membership has increased by 40 per cent.

“The Olympic legacy is alive and well in Mill Hill, and that is entirely due to the combined efforts of our coaches and the Saracens staff.

“We are showing how a rugby club and an athletics club can work together, creating a model that can work elsewhere.”