That’s true, according to some new research. But the full picture is more complicated, and the findings raise an obvious question: What enables and sustains a couple’s long-term romantic and sexual connection to begin with? Let’s take a look.

This study focused on recently married couples, and it found links between the frequency of sex and it’s positive impact on the relationship over time. Previous research has also found a similar effect among older couples. Needless to say, if both partners enjoy sex per se (and presumably with each other) then yes – that’s likely to enhance their relationship satisfaction. But what enables that, in itself? We know that long-term relationships often head south over time. Diminished energy and connection in your relationship inevitably affects you and your partner’s sexual connection. That is, the state of your overall relationship will follow you right into the bedroom.

So, just having sex in the absence of a thriving relationship is unlikely to be very pleasurable. Nor will that translate into more marital satisfaction over time, and can actually diminish it. Mental health professionals who’ve worked with relationships issues recognize that from our patients’ experiences in psychotherapy. True, some couples try to smooth over a flatlined or troubled relationship by trying to “just have sex” anyway. Or by having “make-up sex,” or even “angry sex” after a fight. Many couples look for ways to recharge their sexual relationship by turning to the latest sexual techniques or suggestions that the constantly appearing books, magazine articles and workshops offer up.

These are understandable but misguided efforts, and they reflect a broader problem. We absorb very skewed notions about sexual needs, behavior and romantic relationships as we grow up in our society. I described some of the dysfunctions that result in this previous essay about the differences between “hook-up sex,” “marital sex” and “making love.”

But in contrast, couples’ actual experiences and some empirical research show what partners do when they are successful at sustaining positive connection, emotionally, and sexually. In essence, they build and live an integrated relationship. That’s one that combines transparency in your communications, conscious mutuality in decision-making, and creating conditions for maintaining erotic energy in your physical/sexual life.

I describe some of those below, and their key role becomes more evident when looking at the actual findings from that study of recently married couples. Conducted by Florida State University and published in Psychological Science, It looked at whether frequent sex might not only sustain partners’ positive connection between periods of sexual activity, but also might strengthen their relationship satisfaction over the long-term.

The researchers found that a single act of sex produced an “afterglow” for couples that lasted for 2 days. More significantly, those couples reported greater marital satisfaction 4 to 6 months later, compared with couples who reported a weaker sexual afterglow.

According to lead author Andrea Meltzer, “Our research shows that sexual satisfaction remains elevated 48 hours after sex, and people with a stronger sexual afterglow — that is, people who report a higher level of sexual satisfaction 48 hours after sex — report higher levels of relationship satisfaction several months later.” The research was based on data from two independent, longitudinal studies of a total of 214 couples, and is described in detail in the journal’s news release.

But the study also found that some couples didn’t experience much “afterglow” after sex. And more significantly, all couples’ marital satisfaction declined between the beginning of the study and its follow-up 4 to 6 months later – although those who had higher initial satisfaction experienced less decline.

So decline occurred over time, regardless of the degree of “afterglow.” Actually, that’s pretty consistent with what most long-term couples experience…and lament about. When your relationship declines, that affects your sex life. The researchers’ conclusion that “sex functions to keep couples pair-bonded” overlooks that reality. That is, no new sexual techniques or efforts to reenergize sexual passion will help much when your relationship’s vitality is ebbing away.

What Helps?

A sustaining, energized sexual relationship is a product of an integration of multiple facets. It grows over time from being in synch with each other’s values, your outlook about life; your desires and fears about your life journey together; your life goals, both individually and as a couple. Essentially, it’s a spiritual connection; a sense of being on the same wavelength with your partner. If that core grows, it will fuel a sustainable romantic connection — which, in fact, research shows most couples desire.

I think it’s useful to see three dimensions of an integrated relationship. Each reinforces and strengthens the other: Radical Transparency, Sharing The Stage, and building Good Vibrations.

This article provides more description of each of these. But in brief, Radical Transparency means communicating truthfully and completely to your partner. It’s two-way: Being fully open to hearing your partner’s feelings, wishes, desires, and differences from yourself; and revealing your own to your partner without inhibition or defensiveness. It includes each other’s vulnerabilities, fears, as well as desires and points of view about everything. It’s hard; something to practice.

Sharing The Stage refers to your daily behavior, in which partners show equality and mutuality in the issues of daily life; neither dominating nor submitting to each other in decisions or areas of conflict. For example, in decision-making, especially where there are differences, each of you would think of what best serves the relationship – visualizing it as a third entity — rather than your own ego.

“Good Vibrations” build in your sexual-physical relationship from radical transparency and sharing the stage, as you become more comfortable with open communication and extend that to your sexual desires and needs. It also requires that you take the time and the setting for focusing on each other, physically and sexually. You have to create “adult” time — without the kids. It’s clear that couples who build long-term, thriving relationships will likely sustain a sexual/physical relationship as an integrated part of it – especially if health or other issues make sexual intercourse less possible.

For example, one study of couples in their mid-60s through mid-80s found that couples who had more frequent sexual encounters (including any sexual act, not just intercourse) had happier, more positive marriages than those less sexually active. That study pointed out the connection between the couple’s sexual life and their overall relationship, as I’ve described. And interestingly, research using brain imaging has found that older couples who’ve sustained positive, integrated relationships show brain patterns indicating “very clear similarities between those who were in love long term and those who had just fallen madly in love.”