Investigating the Neurobiological Mechanisms Linking Aerobic Exercise to Cognitive Function in Nigerian Adolescents: A Longitudinal Study

The neurobiological mechanisms through which aerobic exercise exerts its documented cognitive benefits remain incompletely characterised within the African adolescent population, where contextual factors including nutritional status, disease burden, and environmental stressors may modify biological pathways. This dissertation investigates neurobiological mechanisms linking aerobic exercise to cognitive function in Nigerian adolescents through a longitudinal intervention study. A randomised controlled trial is conducted with 160 adolescents aged 13 to 16 years from secondary schools in Rivers State, South South Nigeria, randomly assigned to a 16-week supervised aerobic exercise programme or an active control condition. Outcome measures include performance on executive function tasks (working memory, cognitive flexibility, and inhibitory control), aerobic fitness assessed through maximal oxygen uptake estimation, serum brain-derived neurotrophic factor levels, and inflammatory biomarkers including interleukin-6 and C-reactive protein. Mediation analysis examines whether brain-derived neurotrophic factor and inflammatory pathways mediate the exercise-cognition relationship. Longitudinal findings demonstrate significant aerobic fitness improvements in the intervention group alongside significant cognitive function gains across all three executive function domains. Brain-derived neurotrophic factor increases significantly mediate cognitive flexibility improvements, while anti-inflammatory effects partially mediate working memory gains. Nutritional status moderates the magnitude of brain-derived neurotrophic factor response. This dissertation contributes original neurobiological evidence from a sub-Saharan African adolescent population, challenging the generalisability of exclusively Western neurobiological exercise-cognition models. Keywords: aerobic exercise, cognitive function, neurobiological mechanisms, Nigerian adolescents, longitudinal study