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.
- Runner helping exhausted athlete over finishing line 'is what London Marathon is all about'
- Water stations, urinal bays and MP runners: The 2017 London Marathon in numbers
- Record number of runners to take on today's London Marathon
- Police staff member jailed for child porn possession and theft from work
- PICTURES: Teasy does it! It's World Tea Day today - here are the best places for a cuppa