For a happy relationship, get busy under the sheets once a week (it's science!).

happy couple in bed-sepia
Credit: FOAP

A new study published in the journal Social Psychological and Personality Science says couples who have sex once a week are happier than those who get busy less often.

Researchers collected data from 30,000 Americans over the course of 40 years, and determined the perfect number of times to have intercourse is once weekly. No less. And not even more. That's right; couples who experienced more frequent intimacy were not necessarily happier than the once-per-weekers.

People who reported getting jiggy with it just once per month said they experienced less life satisfaction; in fact, how often a couple has sex seems to make an even bigger difference in their happiness than their amount of wealth.

Lead researcher Amy Muise thinks the reason having sex once per week works so well has to do with it being enough to maintain an intimate connection.

The magic number of times to have sex was true no matter the gender or age of the couple, or how long they'd been perfecting their act in bed. Incidentally, the study did not find a link between sexual frequency and happiness for single people.

So is having sex once a week realistic when, say, you're pregnant, exhausted, puking, and feel disgusting? Or when you have three kids, and no time to shower, shave, or put on a bra? Maybe just sometimes. The key is probably to aim for that weekly romp session most of the time, but not to feel guilty if it doesn't always happen.

How often do you think is the right number of times to hop in bed with your partner?

Melissa Willets is a writer/blogger and a mom. Follow her on Twitter (@Spitupnsuburbs), where she chronicles her love of exercising and drinking coffee, but never simultaneously.