A new U.K. spot for Fitbit's new Ionic smart watch puts the spotlight on middle-aged people trying to keep fit, to the tune of "Happy Birthday to You," which came out of copyright last year.

In the spot, we see characters like a determined middle-aged runner pounding the suburban streets, an somewhat portly cyclist shaving his legs to prepare for a race, a triathlete squeezing into his wetsuit, a grey-haired guy lifting impressive weights and a father at the start line of a "Tough Mudder" style event. The ad concludes with the words "Some numbers mean more than others," and the hashtag #StillGotIt.

The ad is by FCB Inferno, which has pursued similar themes in its award-winning work for Sport England, and was directed by Ian Derry at Archer's Mark. FCB won the Fitbit account in August this year.

"We wanted to challenge the unrealistic portrayals of sportsmen and women in the media, and the challenge was to do this in an inspiring way," says Sharon Jiggins, managing director of FCB Inferno. "The result is a fun, and we hope, motivating piece of work embracing athletes of all levels and abilities."