American old age has undergone a facelift. For the pensioners of adult active retirement community Sun City Arizona, frail and weak is so last century. These super-fit seniors are doing everything they can to fight off old age. But what happens when you send four young unfit, unhealthy Brits to live with some of the fittest pensioners in the world?

19-year-old lager-swilling mummy's boy Frazer Danbury, 21-year-old tanaholic student Judy Lockhart, 18-year-old overweight smoker Louise Crossland and 22-year-old out-of-shape computer gamer Ali Yildirim are about to meet their fate. They don't know it yet, but for the next week they will be staying with 76-year-old Norb Matelski and his 60-year-old wife Mari, and 71-year-old Sharon Billeter and her octogenarian boyfriend Tom Rigley. All four hosts might be in their retirement years, but they are in peak condition. Spending hours a day in the gym and pool, they are looking forward to whipping the lazy young Brits into shape.

Over a life-changing week, the Brits are forced to bin the burgers and fries, adopt the pensioners' extreme fitness regime and be pushed to their emotional and physical limits. And at the end of the week they compete in a swimming competition against Sun City's champion swimming team - to try and prove they're fitter than a pensioner.

Will overweight Louise overcome her low self-confidence? Can Judy put her swimming strop behind her for the team? And how will the young Brits fare in the final competition? Will they swim themselves to victory - or face defeat at the hands of the super-fit seniors? Show less