Jane Tomlinson has run a series of gruelling races

The mother-of-three from Rothwell in Leeds is taking part in the 20-mile route around Nidderdale on Sunday.

Mrs Tomlinson, aged 40, has set herself the goal of raising �1m for charity.

Her latest fundraising effort comes after she vowed not to do any more challenges following her epic 36-day bike ride from Rome to Leeds in June.

Since then she has completed the Gatorade Half-Ironman Triathlon in Dorset.

She also finished the London Triathlon for the third time and in July she took part in the Salford Triathlon alongside her daughters Suzanne, 19, and Rebecca, 16.

Mrs Tomlinson, who has so far raised �850,000 for charity, has breast cancer and doctors diagnosed her case as incurable in 2000.