Childhood fitness linked to reduced risk of depression in adulthood, study finds

A pioneering long-term Australian study reveals that children with higher levels of fitness are less likely to develop depression later in life, emphasising the importance of physical activity in mental health prevention.

A long-running Australian study suggests children who are fitter in middle childhood and adolescence may face a lower risk of depression as adults, adding to a growing body of evidence that physical health and mental health are closely connected. Researchers from the University of Tasmania and Adelaide University analysed data from the Childhood Determinants of Adult Health study, which tracked participants for more than 30 years.

The team followed more than 1,000 Australians who were aged 7 to 15 in 1985 and later reassessed them when they were in their late 30s to late 40s. Childhood fitness was measured through tests including a 1.6 kilometre run to assess cardiorespiratory fitness, along with standing long jump and, for a smaller group, cycling and grip-strength tests. Decades later, participants completed a World Health Organization interview to determine whether they had ever experienced depression.

According to the University of Tasmania, cardiorespiratory fitness showed the clearest link with later mental health. Children and teenagers who performed better on aerobic fitness tests were less likely to develop depression as adults, and the association appeared stronger among females. Researchers said the finding does not prove that low childhood fitness causes depression, but it suggests early fitness may be one factor among many that shape long-term mental health.

Dr Brooklyn Fraser of the Menzies Institute for Medical Research said the length of the study gave researchers a rare chance to look at how early-life fitness relates to mental health many years later. Lead author Dr Kylie Smith said depression has multiple causes and that fitness may be only one part of the picture, while Professor Grant Tomkinson of Adelaide University said modifiable factors that could reduce depression risk are urgently needed. He added that fitness is something people can change, making it a possible target for prevention.

The findings fit with earlier research pointing in the same direction. A Dutch study reported by ScienceDaily found that replacing daily television time with other activities lowered depression risk, particularly in middle age, while separate studies have linked better aerobic and muscular fitness with lower rates of depression and anxiety. Other research has also suggested that even low-to-moderate exercise, such as walking or gardening, can be associated with better mental health, reinforcing the idea that movement matters across the life course.