The same is true for social fitness.

It’s not easy to take care of our relationships today, and in fact, we tend to think that once we establish friendships and intimate relationships, they will take care of themselves. But like muscles, neglected relationships atrophy. Our social life is a living system. And it needs exercise. You don’t have to examine scientific findings to recognize that relationships affect you physically. All you have to do is notice the invigoration you feel when you believe someone has really understood you during a good conversation, or notice the tension and distress after an argument, or the lack of sleep during a period of romantic strife.

Focus first on what’s working well. This is the easiest place to begin. Take a look at the relationships on the energizing side of your social universe and consider how you might solidify or encourage what’s great about them. Tell (and show!) those people how much you appreciate them, and why. It never hurts to double down on what’s already bringing energy and vitality into your life. These relationships are already rolling, but there are usually one or two that have slowed down and need a little push to get up and running at full tilt again. Even good relationships tend to repeat the same routines over and over. It might be time to try some new things with them.

If we accept the wisdom—and more recently the scientific evidence—that our relationships really are among our most valuable tools for sustaining health and happiness, then choosing to invest time and energy in them becomes vitally important. And an investment in our social fitness isn’t only an investment in our lives as they are now. It is an investment that will affect everything about how we live in the future.

We expected that empathic accuracy—getting the right answer about what your partner was feeling—would correlate with a stronger sense of relationship satisfaction. This correlation was certainly there—understanding how your partner is feeling is a good thing.

But more important than that, especially for women, was the empathic effort involved. If a person felt their partner was making a good-faith effort to understand them, they felt more positively about the interaction and about the relationship, regardless of their partner’s accuracy.

To put it simply, understanding another person is great, but just trying to understand goes a long way in building connection.

Some people do this automatically, but efforts to understand others can also be deliberate, intentional behaviors. It needn’t come naturally to you at first, but the more you try, the easier it will get. The next time you have the opportunity, try asking yourself:

How is this person feeling?

What is this person thinking?

Am I missing something here?

How might I feel if I were in this person’s shoes?

And when you can, let them know that you’re curious and trying to understand—a small effort that can have an enormous impact.

Henry’s realization about wanting to be around people also teaches us an important lesson—not about retirement, but about work itself: the people we work with matter. It’s important to look around our workplaces and appreciate those coworkers who add value to our lives. Since work is often so shrouded in financial concerns, in stress and worry, the relationships we develop there sometimes don’t get their due. We often don’t notice how significant our work relationships really are until they’re gone.