In a recent article published in the International Journal of Behavioral Nutrition and Physical Activity, researchers assessed whether physical inactivity in early childhood affects mental health in middle-aged children.
Background
Over 50% of mental health disorders arise before middle childhood at the age of 14 years or less. However, these might continue beyond childhood and adolescence, highlighting the need to prevent them in childhood.
Participation in sports and moderate to vigorous physical activities (MVPA) enhances cognition and mental health by changing the brain’s structure and functionality. It also promotes the release of endorphins to ease pain, generate feelings of euphoria, reduce depression, and increase overall well-being.
Another well-recognized theory is that physical activity improves mental health in children by changing behaviors. It increases energy expenditure to improve their sleep volume and pattern and reduces cognitive deficits due to inadequate sleep. Furthermore, engaging in physical activities and sports fulfills basic psychological needs, such as social connectedness, high self-esteem, and attainment of life goals.
Systematic reviews, like the one done by Peng et al., reported that a physical activity intervention might moderately improve depression in adolescents aged 12–18. Likewise, Hale et al. concluded that these interventions positively affect mental health in 6 to 11-year-olds but did not clarify whether they reduced ill-being in children.
Although several studies have suggested that MPVA improves mental health outcomes in children, their findings were inconsistent. Thus, there is a need for more studies using device-based physical activity assessments to improve quality. Moreover, since many developmental changes occur in the brain during ages 6-11, identifying the effects of physical activity on the psychological outcomes in middle-aged children is crucial.
About the study
In the present study, researchers enrolled children aged 5-6 and 10-11 years, measured their physical activity, sedentary time, and subsequent measurements of SDQ, which helped them explore whether device-based physical activity assessments in early childhood could help predict mental health in later childhood.
For physical activity and sedentary time data, they used the ActiGraph GT3X accelerometer, which all participants wore on their right hip for four days during waking hours, including at least one weekend day. The accelerometer collected all data at a 30 Hz frequency, which helped the researchers compute physical activity volume and intensity.
Further, the researchers performed mental health assessments using the Strengths and Difficulties Questionnaire (SDQ). They asked each participating child’s parents to fill in their SDQ comprising five sub-scales. They summed scores from all subscales (hyperactivity/inattention, behavioral problems, peer problems, emotional problems except prosocial behaviors) and calculated the total difficulties scores. Trained nurses measured their height and weight to compute their body mass index (BMI).
The team used multiple linear regression models to estimate the associations between physical activity, sedentary time, and SDQ subscales. They stratified findings by gender and adjusted for age, BMI, family size, maternal education, and accelerometer wear time. Additionally, they accounted for SDQ scores at age 5–6 to track mental health over time.
Results
Of 1,070 children having valid physical activity data, only 850 aged 10-11 (438 boys and 412 girls) provided a valid SDQ questionnaire. Data indicated that among all children aged 5-6 years, boys were more physically active than girls, albeit the total accelerometer wear time of both genders was comparable.
The team assessed physical activity in children with an average age of 5.11 ± 0.89 years. However, they made the first and subsequent SDQ measurements in children, with an average age of 5.88±0.39 years and 10.57±0.55 years, respectively.
The results showed that higher physical activity levels among children aged 5–6 lowered peer problem scores at ages 10–11 in both boys and girls. Conversely, sedentary time at age 5–6 increased peer problem scores at age 10–11. Adjustments for SDQ scores at age 5–6 did not change the relationship between MVPA and peer issues. Increased MVPA and less sedentary time were associated with higher hyperactivity scores in boys (not girls) and weakened after adjusting for hyperactivity scores at age 5–6.
Participation in sports helps build social skills and improve social competence, which, in turn, could avert the development of peer issues. Children tend to gravitate towards peers who exhibit similar behaviors, like playing the same sports, while isolating others, justifying why engaging in MVPA positively impacted boys’ peer relationships in this study.
The study results also showed the positive impact of MVPA at age 5–6 on girls’ peer relationships at age 10–11, offering evidence for supporting young girls to engage in sports from early childhood. Moreover, it might help promote equal opportunities for girls to enjoy MVPA from an early age.
Athletic ability and sports participation raise the popularity and social recognition of boys, but girls do not feel the need to participate in sports to shape their peer relationships. Yet, future works must fetch insights into how sedentary behaviors can impact the mental health of all children, irrespective of gender.
A meta-analysis showed that children with attention deficit/hyperactivity disorder (ADHD) exhibit higher MPVA levels than other children; thus, actigraph might overestimate physical activity in these children. Indeed, it is not deemed fit for monitoring ADHD cases in ambulatory activities. Consistent with these observations, actigraph-assessed physical activity levels in this study did not protect against hyperactive symptoms.
Similarly, studies documenting physical activity volume and intensity via questionnaires could fetch discrepant/inconsistent findings because people (in most cases) fail to recall those parameters.
Conclusion
Taken together, the study findings shed light on the intricate relationship between physical activity, sedentary time in early childhood, and mental health issues in middle-aged children. Understanding these relationships could help develop effective and targeted strategies to improve mental health in children.