Hundreds of runners, walkers, cyclists and swimmers hit the borough's tracks, bikes and pools at the weekend to raise thousands of pounds for Sport Relief.
Around 220 people, many in colourful fancy-dress, donned their running shoes for the charity bonanza's showcase event, the Sport Relief mile at the Croydon Arena in South Norwood.
Many more plunged into pools in the borough's leisure centres for six swimathons, while some schools and families held their own fundraising fun days.
Students and staff at Oasis Academy Coulsdon together cycled a gruelling 2,500 miles - the distance from Croydon to Africa - as well taking part in laser tag, table tennis and fitness challenges.
A team of more than 70 pupils and parents from St David's School in Purley joined in the action for the Sport Relief mile.
Mum Deborah Roberts, whose seven-year-old son Ben goes to the school, organised the group.
The 37-year-old said: "It was a really nice day and the kids have a great time. Some of them enjoyed it so much they kept going and did a second mile."
Ben, a Year 3 pupil, added: "It was really good fun. I like Sport Relief because it helps people who have really tough lives."
Tania Rahman, 37, of Thornton Heath, said the Arena had "a great atmosphere".
She added: "We were lucky with the weather, despite a few showers. It was nice to be in a family atmosphere."
The x-ray department at Croydon University Hospital also joined in the fun, taking turns at having 30 minute stints on a trampoline and exercise bike.
South London Harriers also held a Sport Relief mile at Woodcote High School.
- Croydon Council to outsource adult education services in face of Government cuts
- As it happened: all the action from Anthony Joshua's world title fight at The O2
- Mayor Sadiq Khan to London's EU migrants: 'You are welcome here'
- Driver escapes injury as car crashes into house
- EU Referendum 2016: As Britain votes to leave, how did your borough vote in south west London and north Surrey?