Couples who have sex like rabbits are no happier than those who are intimate once a week, a study has found. Contrary to popular thinking that the more sex there is then the happier the relationship, researchers at the University of Toronto-Mississauga found that this association levelled out at once every seven days.

The team, which published its findings in the journal Social Psychological and Personality Science, looked at data taken over 40 years from 30,000 Americans. Lead researcher Amy Muise said: "Although more frequent sex is associated with greater happiness, this link was no longer significant at a frequency of more than once a week. Our findings suggest that it's important to maintain an intimate connection with your partner, but you don't need to have sex every day as long as you're maintaining that connection."

In three different studies analysed, the scientists looked at sexual frequency and happiness. The data was mainly focused on heterosexual couples who were either married or in long-term relationships. One study looked at 25,000 couples, and it found that happiness increased with sexual frequency but that this only held true up to one session a week.

In another study, researchers looked at 2,400 married couples over 14 years and found there was no strong link between sexual frequency and overall life satisfaction – but people were more satisfied with their relationships when sexual frequency increased to once per week. There were no noticeable benefits of having more sex than this, it found.

And another survey found that sex was more important than money when it came to happiness in a relationship. There was a greater difference in relationship satisfaction between people who had sex once a week compared to once a month to those who earned between $15,000 and $25,000 a year and those earning $50,000-$75,000. Less sex caused greater relationship dissatisfaction than less money. "People often think that more money and more sex equal more happiness, but this is only true up to a point," Muise said.

She said that while couples should not have more sex to reach the once-a-week goal, they should address whether they are happy with sexual frequency. "It's important to maintain an intimate connection with your partner without putting too much pressure on engaging in sex as frequently as possible," she said.