The Good Life (1975)

Tom worries that they haven't made provision for their old age, when they'll be too infirm to follow their self-sufficient lifestyle. Concerned about their old age, the Leadbetters take out a 14th life policy on Jerry, and take up keep-fit. When Tom boasts that his digging and gardening keeps him fitter than Jerry's jogging and rowing machine, they end up having a long-distance race.