Research involving over 5,500 US adolescents suggests that increasing daily steps may improve mental health outcomes and brain structure, highlighting accessible ways to support young people’s wellbeing.
A larger daily step count in early adolescence may be linked to better mental health a year later, according to research that tracked more than 5,500 young people in the United States. The study, carried out by researchers at King’s College London and the University of Massachusetts Amherst, examined whether everyday movement such as walking to school, playing sport or simply being active during the day was associated with later changes in mood and behaviour. It found that adolescents who logged more steps tended to report fewer mental health problems, with no clear point at which the benefit stopped rising.
The findings, published in JAMA Network Open, were based on data from the Adolescent Brain Cognitive Development Study, a large long-term project following child health and brain development across 21 sites in the US. Participants wore Fitbit devices for three weeks when they were aged 11 to 12, allowing researchers to measure activity objectively rather than relying on self-reported exercise habits. A year later, mental health was assessed using the Child Behaviour Checklist, a standard questionnaire completed by young people and their parents that looks for symptoms including anxiety, low mood and behavioural difficulties.
Researchers reported a clear pattern: teenagers taking fewer than 5,000 steps a day had the highest level of symptoms, while those averaging around 8,000 steps did better, and those reaching 12,000 steps or more appeared to have the fewest problems. The most active adolescents also showed slightly thicker brain tissue in two regions involved in movement and emotional regulation, which helped explain part of the connection between higher step counts and better mental health. The study did not find a link between the number of steps and academic performance.
Divyangana Rakesh, senior lecturer in neuroscience and psychology at King’s College London and senior author of the study, said the work offers some of the clearest evidence yet that a simple, low-cost measure such as daily step count is connected with how adolescent brains and mental health develop. Qingyang Li, the study’s lead author, said the results are an early step towards understanding which parts of the brain may be involved in the relationship.
Amanda Paluch, associate professor of kinesiology at the University of Massachusetts Amherst, said the message for families is that physical activity does not have to mean organised sport or elite training. She said increases of 1,000 to 2,000 steps a day, from any starting point, were associated with better brain structure and mental health outcomes, suggesting that small changes such as walking to school or active play may be worthwhile. However, because the study was observational, it cannot prove that walking more directly improves mental health, and the researchers said it remains possible that teenagers with fewer symptoms were simply more active to begin with. The brain differences were small, and relatively few participants recorded very high step counts, so the researchers said it is not yet clear whether the same pattern continues beyond the levels measured in the study.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
