Michelle Heaton has had her weighty ups and downs. But a new career as a fitness trainer and a goal to complete the London Marathon has given her a new lease of life.The 30-year-old paraded her athletic body on a break in Miami with fiancé Hugh Hanley.Sporting a lilac halternecked bikini, the results of Michelle's hard work could clearly be seen in her slim but muscular frame. Closer than close: Michelle Heaton enjoyed a pre-marathon break in Miami with fiancé Hugh HanleyThe former Liberty X singer is running the London Marathon on Sunday, April 25 as part of Virgin multi-millionaire Richard Branson's team alongside Jenni Falconer and Strictly Come Dancing runner-up Ricky Whittle.And feeling the heat she took time to cool off underneath the...