Marathon runner Paula Radcliffe hopes to have broken another sporting record by joining the Tesco Great School Run this week.

The retailer held what it expected to be the world's largest simultaneous running event, involving thousands of schools around the country. At least 250,000 seven to 11-year-olds took part in the initiative that aimed to encourage them to think about the importance of physical exercise as part of a healthy lifestyle as well as persuade teachers that sport should feature high on the academic agenda.

Radcliffe joined schools in Leicestershire, Bedford and London on the day, where she was taken by heli­copter to each event and spent time chatting to kids and giving out some expert running tips. Tesco had also devised a five-week learning programme of classroom and physical activities in the run-up to the event.

Tesco's head of corporate responsibility, Deborah Stones, said: "We hope every­one enjoyed their day and look forward to hopefully being able to confirm the Guinness World Record."