A walk around the neighbourhood or the nearby park, a game of football or an afternoon at the swimming pool might do more than help teenagers burn off energy.
Scientists studying young adolescents found a link between their daily total step count and their mental health a year later. But it wasn’t just their activity levels that caught researchers’ attention. Brain scans revealed another intriguing clue.
What scientists discovered about teen mental health
Researchers from King’s College London and the University of Massachusetts Amherst analysed data from 5 515 adolescents in the United States.
At an average age of almost 12, participants wore Fitbit devices for three weeks to measure their daily steps. A year later, researchers assessed their mental health using questionnaires measuring symptoms such as anxiety, low mood and behavioural problems.
Those taking fewer than 5 000 steps a day had the most mental health problems, on average. Adolescents averaging around 8 000 steps had fewer, while those recording 12 000 or more had the fewest.
The association continued across the range of step counts studied, with no evidence that it levelled off.
They published their findings in JAMA Network Open.
What daily steps could mean for the teenage brain
Brain scans revealed that higher daily step counts were associated with slightly greater cortical thickness in two regions: the paracentral region, involved in movement, and the rostral anterior cingulate, which contributes to cognitive and emotional processing.
Statistical analysis suggested that differences in the paracentral region accounted for part of the association between daily steps and fewer mental health problems a year later.
However, the researchers could not establish that walking caused these brain differences or directly improved mental health. The study also found no significant overall association between daily step counts and academic performance a year later.
Do teenagers need to reach 12 000 steps a day?
The study did not establish a daily step target for supporting teen mental health. Dr Amanda Paluch, an associate professor of kinesiology at the University of Massachusetts Amherst, highlighted findings suggesting that increments of 1 000 to 2 000 daily steps were associated with better mental health and brain-structure outcomes.
These were associations, however, not proof that adding a specific number of steps would produce the same benefits for every teenager.
For South African families, movement can take many forms, from walking and swimming to dancing or playing outside. The study measured daily steps, so it cannot establish whether walking offers greater mental health benefits than other activities.
Can walking improve teen mental health?
There is an important caveat: this was an observational study, meaning it identified associations rather than proving cause and effect.
Although researchers accounted for earlier mental health problems, other factors could still explain the relationship. For example, adolescents experiencing fewer difficulties might already be more active.
The questionnaires measured symptoms and behavioural difficulties, not clinical diagnoses of mental health conditions. Further research is needed to understand the relationship between movement, brain development and wellbeing.
For parents and caregivers, the takeaway is not that every teenager needs to reach 12 000 steps a day. Encouraging enjoyable, regular movement may be worthwhile without turning a step counter into another source of pressure.
Researchers also made a connection between teen mental health and the amount they sleep in recent years.
How can parents encourage teenagers to move more?
Getting teenagers moving does not have to mean signing them up for a gym or insisting they reach a daily step target. Small changes to family routines can help make activity part of everyday life.
Make screen breaks active: Encourage teenagers to take a short walk, stretch or go outside between gaming sessions or while watching television. The aim is to replace some sedentary time, not ban screens altogether.
Let them choose: Whether it is dancing, swimming, cycling, skateboarding or playing a team sport, teenagers are more likely to stick with activities they actually enjoy.
Make it social: Walking the dog, kicking a ball around with friends or going for a family walk can make movement feel less like exercise and more like time together.
Build activity into the day: Where it is safe and practical, walking short distances, taking the stairs or helping with gardening can add movement without requiring a separate workout.
Lead by example: Parents who make time for their own physical activity can encourage teenagers to do the same.