SACRAMENTO, Calif. — Just in time for New Year's resolutions, a new study underscores that a solid relationship may be good for your health.

Researchers at the University of California's Los Angeles and Davis campuses have found that women in happy marriages recover more quickly from workday stress than women in unhappy ones.

The study, part of a detailed examination of a week in the lives of Los Angeles-area families, may help explain how health benefits of a good marriage play out differently for men and women.

The research is a reminder that our bodies respond to what is happening in our emotional lives — a potent New Year's message.

"Maybe in addition in promising to go to on that diet, you could also promise to sit down with your spouse and talk to them," said Rena Repetti, a psychology professor at UCLA.

And as more people opt to remain single, it will be interesting to see if other close relationships in people's daily lives can provide similar physical benefits, said Davis professor Adrienne Nishina.

Nishina and Repetti, along with University of California Los Angeles doctoral student Darby Saxbe, wrote the study on stress and married life being published in the January issue of Health Psychology.

They found that the stress hormone cortisol, which normally rises and falls throughout the day, followed different patterns depending on gender and the state of the marriages.

Men, whether in happy or unhappy marriages, tended to rebound quickly from a busy, stressful workday, their cortisol levels showed.

So did women in happy marriages.

But women in less happy marriages rebounded more slowly, indicating that it took them longer to shed workday stress.

"We know everyday stress is associated with more health problems in the future," so this differing cortisol response may help explain a gender-related twist in health and marriage, said Saxbe, the study's lead author.

A number of other studies have found that married men tend to live longer and recover from illnesses better than single ones. For women, the effect is more nuanced, with the health boost generally going only to women in happier marriages.

The study suggests that women who are less satisfied in their marriages may have trouble handling other stresses, and may be more prone to stress-related illnesses, Saxbe said.

Women in unhappier marriages also had less variation in cortisol levels throughout the day, a pattern other researchers have sometimes linked to health problems.

"With this study, we're really moving into how specifically happy and strong marriages might be influencing our actual physical health," said Nishina, a professor in UC Davis' department of human and community development.

"This is something we have guessed about in the past," she said, but now "we're starting to look at the mechanisms by which that might happen, the actual physiological processes."

Nishina contributed to the marriage stress study while doing postdoctoral work at UCLA.

Researchers were able to monitor job stress, home life and hormones in such detail by recruiting 30 couples who were willing to fill out surveys and keep diaries, be videotaped extensively at home, and collect multiple saliva samples.

Stress was only one aspect probed by anthropologists, linguists, psychologists and educators working on the project for UCLA-Sloan Center on Everyday Lives and Families. Parent-child relationships, clutter, use of space at home and other factors are also being investigated.

"A slew of papers are going to be coming out ... it is like a gold mine," said Repetti.

All the families studied had mortgages, at least two children and two working parents.

Researchers relied on a widely used survey of spousal compatibility to categorize marriages as happier or less happy.

While the study offered more details on precisely how relationships may affect our health, scientists have long known the two can be linked.

Nishina, who now focuses on childhood bullying, said children picked on at school get more headaches and stomachaches.

Imaging research has found that social stress can light up the same pain regions of the brain activated by physical injury.