Together for 85 years, the world’s oldest couple shares their tips for making a relationship last

When you’ve been married to the same person for 80 years, it’s safe to say you know a thing or two about relationships. Charlotte and John Henderson, the world’s oldest living couple, met in 1934 as students at the University of Texas at Austin. On December 22, they’ll celebrate their “oak” anniversary with eight decades of marriage. In an interview with the Washington Post, 105-year-old Charlotte and 106-year-old John shared their secrets to a happy, healthy, and long marriage.

According to John, the couple has made the old adage “never go to bed angry” their relationship motto. All bickering and fighting gets resolved before they call it a night—and good sleep hygiene isn’t the only thing keeping their marriage on the upswing.

Apart from keeping the number of arguments to a minimum, the couple leads an active lifestyle that revolves around moderation. The Hendersons enjoys nutritious foods (think: fruits, veggies, whole grains, and lean proteins) and drink very little alcohol. John still makes a habit of going to the gym regularly. And another factor may have contributed to their long marriage: The couple never had children. “[S]o some people have said that’s really why we’ve lived so long,” he says. Make of that what you will.

While their marriage has lasted 80 years, John and Charlotte have been together for 85—”It took her five years to make up her mind that she wanted to get married,” he says—so don’t rush into it.

The longest living people in the world take this approach to exercise and follow these tenets of nutrition.