Grain started her professional road cycling career as part of her mountain bike fitness training program with the British Columbia Provincial Team. She rapidly began excel at it and later received an invitation to join the 800.com pro cycling teams in 2001, following her short stints on Atlanta Velo and Victory Brewing for the next two seasons.[3] Grain flourished her first career success at the Grand Montreal Cycling Tour (French: Tour du Grand Montréal), where she officially earned a first stage triumph.[4]
In 2004, Grain emerged as one of the world's top road sprinters, and mounted consistent podium finishes and a limited number of triumphs to earn the U.S. Pro Tour Championships titles and other cycling tournaments. On that same year, she turned her sights to and took up seriously in track cycling.[2][5] When the Victory Brewing folded out after the 2004 season, Grain left herself with no contract and instead, set up her short retirement to concentrate on her full-time job as a registered kinesiologist in exercise therapy and rehab programs at Saanich Commonwealth Place.[2]
At the start of the 2006 season, Grain returned to her professional cycling career when she signed an exclusive contract with Hong Kong's Giant Pro Cycling. She capped a successful season by taking home the silver medal in the women's elite 8 km scratch race at the UCI World Championships in Bordeaux, France, and mounted top-four finishes in both road and points race at the Commonwealth Games in Melbourne, moving her up to top ten places in the UCI world rankings.[6] Reaching the peak of her sporting career, Grain burst again into the road cycling scene by defending her Tour de Gastown title on that same year, the first being done in 2005.[7]
In 2007, Grain granted license by the Union Cycliste Internationale (UCI) for the Canadian women's pro cycling team, racing under the Expresscopy.com banner.[8] She rounded out another successful season by capturing her first ever and only women's elite road race title at the Canadian Championships in Saint-Georges, Quebec.[9] By the end of 2007 season, Grain joined her teammates Erinne Willock, Alex Wrubleski, and 2004 U.S. Olympian Christine Thorburn as part of the official roster for the Webcor Builders Cycling Team.[10] In July 2008, Grain thrilled again to a sprint finish by claiming her third title at the Tour de Gastown in Vancouver, British Columbia.[11]
Grain qualified for her first Canadian squad, as a 34-year-old, in the women's points race at the 2008 Summer Olympics in Beijing by receiving an invitational berth from the Canadian Cycling Association, based on her top-ten performance in the UCI Track World Rankings.[12] Grain escaped from an early crash (which she fondly called it a "high-speed chess match") that eliminated three other riders off the track to take the ninth spot successfully in a grueling 25-km race, earning a total score of six points in three of the ten sprints.[13][14][15] Shortly after the Olympics, Grain was stunned in a major upset from her inexperienced rival Tara Whitten by taking home the silver in the women's points race at the Canadian Track Cycling Championships in Burnaby, British Columbia.[16]
Upon returning to Webcor Builders Cycling Team for another season in 2009, Grain started her stint by edging out New Zealand rider and 2008 Olympian Catherine Cheatley on a blazing sprint road race to score a second stage triumph at the Tour of the Gila in southwestern United States.[17][18]