Jessica Ennis chatted to Newsround
The Olympic gold medallist Jessica Ennis Hill kicks off Manchester's Great City games today competing in the 110 metre hurdles.
Tomorrow over a quarter of a million people will hit the streets for the biggest 10km run in Europe.
The Manchester Great City games will be her first competitive event after having her baby son last year.
Jessica spoke to Jenny, about the big event and her preparations leading up to the 2016 Summer Olympic games in Rio.