Chicago came to Bermuda last night as more than 50 athletes from the Illinois city took part in International Race Weekend's opening showpiece mile races.

The runners had been enticed to travel to the Island with the promise of an escape from sub-zero winter temperatures in their home town, the intriguing challenge of competing three races on consecutive days, and the likelihood they might get to run alongside athletics legend Kathrine Switzer.

If the Chicago contingent had needed any extra inspiration before their Bermuda Triangle Challenge mile races they got it 24 hours earlier when they broke off from excited cocktail party conversations to listen with near reverence to fellow competitor Ms Switzer.

Her famous story caught the imagination of Bermuda last year when she took part in the inaugural Bermuda Triangle Challenge. Fittingly, she competes again this year wearing race number 261 – the same number she wore as a 20-year-old in 1967 when she became a dramatic catalyst for the breaking down of the barriers that prevented women from taking part in distance running events.

She became the first woman to complete the then 'men-only' Boston Marathon with an official race number, beating an infamous confrontation a few miles into the event when furious race director Jock Semple tried to rip off her race number only to himself be bundled off the road by Ms Switzer's boyfriend and race companion. The resulting photographs and story made news around the world and forever changed the belief that woman could not and should not run marathons.

Now 62, Ms Switzer revealed her love of the sport had been reinvigorated after Thom Gillighan, of Marathon Tours & Travel, challenged her to take part in the first Bermuda Triangle Challenge where she faced a mile race, a 10K and a half marathon on consecutive days. It was the biggest running challenge she had faced in 20 years and after completing the triple-event – and winning the first monetary prize of her 45-year career with a $100 age category award – she found a new keenness towards training, which has carried her through the past few months and brought her back to Bermuda in what she feels is better shape than a year ago.

However, as she spoke to The Royal Gazette, she revealed that getting older is taking its toll and changing her in what she describes as a 'fascinating process'.

"Running is so much harder now, it is like being in a different body. The ageing process has been fascinating. When I come in after a long run I take a shower and then fall into bed and sleep for an hour. It's like a fatigue," she said. And even when she is out running, she sometimes finds herself fighting the urge to stop and lie down to sleep.

Running is her "sanity and vanity", she explains. "I'd go nuts if I didn't run." But now the whole experience is coloured by what she describes as an exploration of getting older.

"I whine and complain more about the wind or the fatigue, whereas when I was younger I'd be out running with snow coming over my head and I never even thought about it, but now things can really get to me."

Already the author of one acclaimed book 'Marathon Woman', Ms Switzer is considering writing another on what it is to be a runner dealing with the ageing process.

Taking part in last year's Triangle Challenge event revitalised her. "I was totally psyched from last year. It reinvigorated me and to win prize money was moving. I'd never won money in all my 45 years of running. It was symbolic," she said. It is also now part of International Race Weekend folklore on account of it taking only 32 seconds to completely spend the $100 after she 'put it on the bar' to share with the other runners.

During the past 12 months Ms Switzer took part in the Wanganui Mayoral Mile in New Zealand, the former site of a grass running track where the UK's Bruce Tulloch and New Zealand legend Peter Snell in 1962 famously raced, with Snell setting a world mile record. Ms Switzer's time of seven minutes 45 seconds was more than 15 seconds faster than her Front Street mile last January.

Other races she has completed recently include a half marathon in South Dakota and another in Fresno, California. But it hasn't all been plain sailing, she was wiped out for two months during the summer after eating a toxic tomato at a New York restaurant.

She is back in Bermuda with the assistance of Race Weekend backer Fairmont Hotels, for whom she has become a fitness ambassador in recent years, promoting a wellness programme for hotel guests.

For many others taking part in Race Weekend the mere presence of Ms Switzer is a major inspirational boost. Fellow Triangle Challengers Ray and Sandy Leone, from Washington State and Vancouver, and Heather Brain and Juliet Kingsford, from Dorset in England, spoke of being "energised" after having the opportunity to listen in on Ms Switzer's interview. And the energy level was markedly higher at the pre-event cocktail party for the Marathon Tours contingent after they had heard from Ms Switzer.

The Chicago Endurance Sports group have lived up to their name, enduring snow and thunderstorms and freezing temperatures as they trained for their Bermuda adventure.

Amongst those who flew out from Chicago in 10F temperatures on Thursday, was Gayle McMurry, who said: "We saw this as a different kind of challenge. Most of us have never been to Bermuda and it's warm here and we decided it would be a wonderful race to participate in."Her husband Mike McMurry added: "Bermuda has a wonderful reputation and my parents came here and loved it. This is a different physical challenge, it is unusual and we're here to see if we can do it."Janine Gauthier explained that the group splits up into smaller training packs to accommodate different pace abilities and the training for Bermuda had begun in earnest in late October and early November.Escaping from Chicago's frigid temperatures was a big bonanza for fellow Chicago resident Holly Jamison, who said: "It's so cold there and we had heard such wonderful things about Bermuda. We decided to make this our destination race in October."Michael Schaffner added: "The three races seem different. I know I can do each individual race, but back-to-back? Well, I have trained."Chicago Endurance Sports coach Jenny Hadfield said: "Everyone has trained together for 14 weeks through thunder, driving rain and six snowstorms. They have also been training indoors to get used to running in the heat. We've never been here before and we're intrigued by the Bermuda Triangle Challenge."

Not from Chicago, but taking part through Marathon Tours, are Dave and Debbie Lemmeyer, from Alexandria, Virginia. For them Race Weekend represents a return to the sport they love after undergoing major surgery. Mr. Lemmeyer had his hip replaced after the 2005 Dublin Marathon, while Mrs. Lemmeyer has undergone two reconstructive surgeries involving numerous screws being put into one of her feet to fix a collapsed metatarsal bridge. Despite the setbacks, they said they are both raring to go in today's 10K.

Any athletes who need a final touch of inspiration before Sunday's marathon and half marathon should consider attending this evening's pasta party at the Fairmont Hamilton Princess, where Ms Switzer will deliver a speech on her career and her historic Boston Marathon episode.