A new study has found that being fit as a teenager could be linked to a reduced risk of suicide as an adult. Researchers at the University of Gothenburg looked at a study of over 1.1 million Swedish men born between 1950 and 1987 who completed their mandatory physical exam for compulsory military service, comparing their results to Sweden‘s national registers of disease and death. They found a link between being physically unfit at age 18 and a significantly higher risk of suicidal behavior later in life – even 42 years later.

“Being in poor physical shape at 18 years of age, measured as the test results on an exercise bike during their medical exam for compulsory military service, can be linked to a risk of suicidal behavior as an adult that is 1.8 times greater,” said Margda Waern, professor at the Sahlgrenska Academy at the University of Gothenburg.

The link between teen fitness and later suicide attempts remained even when researchers controlled for men who suffered from severe depression. The study’s authors have suggested that exercise should be incorporated into teen suicide prevention programs.

The study, published in the journal Psychological Medicine, is based on a report from the Swedish National Board of Health and Welfare that shows Swedish teens have poor mental health compared to other western countries. Other studies have also shown that suicides among Swedes have been increasing for over a decade.

“The teenage years are a critical period in terms of brain development since this is when social and emotional faculties are established,” said Maria Aberg, a researcher at the Sahlgrenska Academy. “Therefore, it was important to do a larger study on the importance of physical fitness in terms of suicidal behavior in this age group.”