More than 800 runners will converge on Endcliffe Park on Sunday.
Organisers of the TenTenTen hopes that the figure will have risen to 1,000 by the time the 10k race through Endcliffe and Bingham Parks starts at 10am. Last year’s field was over 900.
The event, which also offers an option of 2.5k, is in its fourth year and has so far raised more than £24,000 for its nominated charity, Weston Park Hospital Cancer Charity.
It is designed to appeal to everybody from running novices to seasoned pros.
Typical is law student Martina Antosova, aged 23, of Broomhill, who will be running in memory of her granddad, who died of cancer.
She said: “The race will be a perfect opportunity for me to raise sponsorship and donate to a cause so close to my heart.”
Event organiser Doug Banks, said: “We are overwhelmed with the support for TenTenTen and thrilled that it continues to grow and attract new runners each year.”