For a short commute to school or a quick game with friends, the activity may do more than keep you active. New research shows that just about any physical activity may have a positive effect on mental well-being during early adolescence, an age when emotional, social, and brain changes make young people more sensitive to stress and anxiety.
Researchers from King’s College London and the University of Massachusetts Amherst examined data from 5,515 adolescents who took part in the Adolescent Brain Cognitive Development Study in the United States. The participants wore Fitbit devices for three weeks when they were about 11 to 12 years old. The researchers evaluated their mental health roughly one year later.
The results showed a clear association between steps per day and mental health. The adolescents who were doing fewer than 5,000 steps per day tended to have the most mental health symptoms, while those doing the most steps, at, or near 8 000 had fewer. The most steps 12 000 or more, were related to fewer symptoms of the groups.
The team looked at the link between problems like anxiety, poor mood and behavioural problems as reported on the Child Behavior Checklist, a standardised measure, which is filled in by parents. The link persisted even after the researchers took into account problems the adolescents had experienced earlier in their lives.
Crucially, the findings indicated that the association did not end at a certain daily step goal within the range studied. So young people shouldn’t have to work up to a high-fitness goal before habitual activity may be advantageous. A step increase of about 1,000 to 2,000 steps from baseline may be a good place to start.
Researchers also explored if physical activity was linked to variations in brain composition. They found modest differences in the thickness of the cortex in two brain areas, such as the paracentral region (which handles movement) and the rostral anterior cingulate cortex (which manages emotions and other mental activities).
By statistical analysis, the team also found that variations in the paracentral cortical thickness partially accounted for the link between increased step counts and less mental health problems a year later. But the team did not find evidence that increased daily step counts were consistently tied to improved school performance.
The findings give some hints about how brain and physical development may be linked, but do not confirm a direct biological explanation. We will need more research to reveal the ways in which physical activity, mental health and brain development affect each other.
The results endorse an achievable method for promoting activity in the lives of young people. Walking part of the way to school, taking a few short movement breaks while studying, playing outdoor games and going for walks with friends are all simple ways to get more steps without requiring expensive equipment or a formal exercise programme.