More than 1,500 women run, jogged or walked their way around Thornes Park to raise thousands of pounds for Cancer Research UK.
The Race for Life started in the city in 2010 and this year’s event included a tough 10k course as well as a 5k route.
Among those taking part was bride-to-be Jessica Franks, who led her hen party around the 5k course.
Miss Franks, 26, of Darforth Drive, Altofts, made the decision to sign up after her grandmother Glennis Cordingley, 70, was diagnosed with breast cancer last year.
Miss Franks, who will marry Lee Bateman on June 26, said: “I really wanted my grandma to be on my hen party but she just isn’t fit enough for a typical, drinking do.
“We did the Race for Life last year after she was diagnosed and I just decided to get all my hens taking part this time.”
Last year’s event raised £105,000 for Cancer Research UK, and it’s hoped this year’s funds will top £137,000.
ITV Calendar presented Christine Talbot started the race after hundreds of people took part in a warm up led by instructors from Total Fitness gym.
Sarah Threadgall, event manager, said: “It has been such a great atmosphere and it’s been great to raise so much money. By having a 10k course this year, we find that the bigger challenge means that people often manage to secure much more sponsorship.
“All of the money raised goes towards research into more than 200 types of cancer - not just breast cancer as people often assume.
“It has been a really supportive atmosphere, which we find with all our Race for Life events, and as they are open to all levels of fitness, it’s a really good day out for everyone.”