Based on survey responses of 238 married individuals aged 65 years and older, researchers from Florida Agricultural and Mechanical University found that the frequency of sexual activity was a significant predictor of happiness among the couples.

In fact, nearly 60 per cent of people who shagged more than once a month claimed they felt very satisfied with their marriages, compared with 40 per cent of people who got busy less often.

Your takeout: if your marriage has seen better days, you know what to add to your weekly to-do list.