Individual response to continuous and interval training on cognitive and brain-derived neurotrophic factor in adolescents with overweight/obesity.

BACKGROUND

The effects of different exercise intensities on cognitive outcomes and brain-derived neurotrophic factor (BDNF) concentrations in adolescents with overweight/obesity are not yet fully elucidated. This study aimed: (a) to compare the prevalence of responders to cognitive function and BDNF concentration in adolescents with overweight/obesity participating in a 12-week intervention with high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT), and (b) to analyze whether cardiorespiratory fitness (CRF) can explain differences in inter-individual variability between responders and non-responders.

METHODS

Adolescents with overweight/obesity were assigned to HIIT (n = 15), MICT (n = 14), or CG (n = 24). Anthropometrics, body composition, CRF, basal BDNF, and cognitive performance (Trial Making Test (TMT) and Stroop Test (ST)) were evaluated pre- and post-intervention. Training was performed on stationary bikes (3×/week for 12 weeks).

RESULTS

The prevalence of responders in ST and TMT was higher in the HIIT group than in CG (93-62%, p = 0.029; 67-33%, p = 0.043), with no differences in MICT. No group differences were found for BDNF responders (HIIT:73%-MICT:71%-CG:46%, p = 0.263). ST and TMT responders had greater CRF improvements than non-responders.

CONCLUSION

HIIT elicited a higher prevalence of cognitive responders than CG. CRF improvements may partially explain individual variability in responsiveness to cognitive outcomes.

IMPACT: This is the first study to examine and compare inter-individual variability in cognitive function and BDNF levels following MICT and HIIT interventions in adolescents with overweight/obesity; Exercise intensity and improvements in cardiorespiratory fitness are key factors for optimizing the cognitive effects of interventions in youth with overweight; Twelve weeks of supervised HIIT and MICT training led to increased rates of cognitive responders among adolescents with overweight/obesity.