For men experiencing emotional distress like depression, anxiety or thoughts of suicide, having high cardiorespiratory fitness may cut the risk of death in half compared to those in poor condition, researchers say.

“The prevalence of mental health issues is growing in the U.S. and globally,” said lead study author Mei Sui of the University of South Carolina in Columbia. “People are facing many stressors in their daily lives linked to depression, anxiety and other mental disorders.

“Medication to treat these mental problems is not only expensive but also comes with significant side effects such as weight gain,” she told Reuters Health. “Identifying modifiable factors that are beneficial to those with emotional distress has important clinical and public health applications.”

Mental health conditions cost the U.S. about $2.5 trillion in 2010 and are projected to cost the country $6 trillion by 2030, the authors write in Mayo Clinic Proceedings.

To see how cardiovascular fitness might affect healthcare costs and outcomes for people with mental health disorders, Sui and colleagues analyzed data from the Aerobics Center Longitudinal Study at the Cooper Clinic in Dallas, Texas, which conducted preventive health exams on more than 43,000 men between 1987 and 2002.

The researchers focused on 5,240 participants who reported a history of emotional distress, including 2,229 who reported more than one emotional distress condition. To measure cardiorespiratory fitness, participants ran on a treadmill until they were exhausted.

Among men who experienced emotional distress, 46 percent reported depression, 58 percent had anxiety, 51 percent had a history of mental counseling, and 8 percent reported ever having thoughts of suicide.

By the end of the follow up period, there were 128 deaths from any cause.

The researchers found that men with the lowest cardiovascular fitness tended to have higher weight, blood pressure, cholesterol and blood sugar levels and were more likely to smoke and to be sedentary.

In addition, men who reported more than one type of emotional distress were more common in the low-fitness group.

Compared to the lowest-fitness group, men with moderate cardiovascular fitness were 46 percent less likely to die of any cause during the study, and those in the high fitness group were 53 percent less likely to die.

“This significant strong inverse association between high levels of fitness and longevity in men with emotional distress is particularly interesting,” Sui said. “Clearly lifestyle behavior interventions to increase fitness levels could help those with emotional distress.”

Even moderate levels of fitness were associated with a 46 percent lower risk of dying, she noted. This moderate level of fitness means 30 minutes per day of activity such as swimming, jogging or biking, and is the current level recommended under American sports medicine guidelines.

The study mostly included non-Hispanic whites, and Sui would like to see more research about fitness in women and minority groups.

“This was the missing piece of the puzzle. We know now that assessing fitness and treating it should be at the center of mental health care,” said Davy Vancampfort of the University of Leuven Psychiatric Center in Belgium. He wasn’t involved in the current study but recently published an analysis that found people with severe mental illness are at heightened risk for heart disease

“This adds to our call to include assessment of physical activity and treatment to the standard mental health care package,” he told Reuters Health by email. “Mental health care settings and primary care settings should work closely together on this.”

Future research could also look at older populations, follow people for a longer period of time and account for medication such as psychotropic prescriptions in particular, said Brandon Stubbs of King’s College London in the UK.

“One in four of us will at some point experience a common mental illness in our lives,” Stubbs, who wasn’t involved in the study, told Reuters Health by email. “We can no longer view mental health and physical health separately given that they are so inextricably linked.”