Teenagers who are physically fit are less likely to attempt or commit suicide later in life, the results of a new study indicate.

Suicide is a major issue worldwide. Last year in Ireland, more than 500 people died by suicide, but many more attempted it. Researchers around the world are increasingly attempting to focus on factors that can prevent mental health problems and the risk of suicidal behaviour.

Now researchers in Sweden have found a link between exercising in adolescence and a reduced risk of suicidal behaviour later on.

They looked at over 1.1 million men who had undergone an exercise test as part of a medical exam for compulsory military service at the age of 18.

They found that being in poor shape at 18 years of age ‘can be linked to a risk of suicidal behaviour as an adult that is 1.8 times greater'.

Furthermore, this increased risk was still evident 42 years later, i.e. when the participants were 60 years of age.

The researchers from the University of Gothenburg noted that previous studies have shown that exercise is good for the brain and the adolescent years are a very important time.

"The teenage years are a critical period in terms of brain development since this is when social and emotional faculties are established. Therefore, it was important to do a large study on the importance of physical fitness in terms of suicidal behavior in this age group," they explained.

In a previous study, they found that teenagers who are physically fit are also at a reduced risk of suffering severe depression in later life.

"But even when we exclude individuals who suffer from severe depression in connection with suicide or attempted suicide, the link between poor physical shape and an increased risk of suicidal behaviour remains," they pointed out.

One theory for the findings is that ‘the brain becomes more resistant to different types of stress if you are physically active'.

The Swedish team believes that physical exercise should be included in suicide prevention programmes aimed at young people.

Details of these findings are published in the journal, Psychological Medicine.