Childhood Fitness Linked to Lower Depression Risk in Adulthood, Study Finds

A new Australian study that followed participants for more than three decades suggests that physical fitness during childhood may be associated with better mental health later in life.

Researchers from the Menzies Institute for Medical Research at the University of Tasmania analyzed data from a national fitness survey conducted in Australia in 1985. The original survey assessed approximately 8,500 schoolchildren between the ages of 7 and 15 through a series of physical fitness tests, including a 1.6-kilometer run or walk, a standing long jump, and a handgrip strength test. Some participants also completed an exercise bike assessment.

Between 2014 and 2019, when the participants were between 36 and 49 years old, researchers followed up with approximately 1,080 of them. Through interviews, they assessed whether participants had experienced depression at any point in their lives.

Childhood Endurance Linked to Lower Depression Risk

The findings revealed that approximately 17.6% of participants had experienced depression, with higher rates among women than men. The most notable association involved running performance: children who completed the running test faster than most of their peers had approximately a 15% lower risk of developing depression in adulthood.

The association was particularly strong during the earlier years of the follow-up period. Aerobic fitness measured through the exercise bike test showed a similar trend, while performance in the standing long jump and handgrip strength tests was not consistently associated with depression risk. These findings suggest that cardiovascular endurance, rather than muscular strength or explosive power, may be particularly relevant to long-term mental health.

Researchers proposed several possible explanations for the connection. Aerobic exercise stimulates the release of endorphins and increases the production of substances that support brain health. It may also help regulate inflammation and stress hormones, potentially contributing to emotional well-being. Beyond these biological effects, physical fitness may offer psychological and social benefits. Children who feel physically capable may develop greater self-confidence, a more positive body image, and stronger social relationships through sports and active play.

Why the Findings Should Be Interpreted With Caution

Despite the findings, researchers emphasized several important limitations. Because the study was observational, it identified an association between childhood fitness and adult depression rather than proving that physical fitness directly prevents depression.

Only approximately one in eight children from the original survey participated in the follow-up, raising questions about whether the findings accurately represent the broader population. In addition, participants were asked to recall experiences spanning roughly 30 years, introducing the possibility of inaccuracies in their recollections. Some of the findings also failed to reach statistical significance after researchers accounted for additional factors.

One of the study's authors emphasized that physical fitness is likely just one of many influences on mental health, while an independent expert acknowledged the association but urged caution in interpreting the results.

Although the research does not establish that childhood exercise prevents depression, it highlights a potentially important connection between cardiovascular fitness early in life and psychological well-being decades later. The findings offer another reason to encourage children to stay physically active, while recognizing that mental health is shaped by a complex combination of biological, psychological, and social factors.