The Benefits of Acute Exercise for Children's Cognition are Associated with Trait Anxiety.

INTRODUCTION:Children's anxiety is associated with decreased cognitive performance. One well-established behavioral intervention to transiently improve cognitive performance in children is acute aerobic exercise (AAE). Thus far, however, it is unclear whether the benefits of AAE on cognition vary based on individual differences in children's anxiety level. Therefore, we investigated whether trait anxiety levels mediate the effects of AAE on cognitive outcomes in preadolescent children. METHODS:Ninety-five preadolescent children (9-11 years, 41 females) underwent two experimental interventions in a random, crossover, and counterbalanced design: an exercise protocol (20 minutes of walking at 65-75% of HRpeak) and a non-exercise control (seated rest). Behavioral indices of cognitive performance (accuracy, reaction times, response time variability) were assessed before and after each intervention using a modified flanker task. The effects of each intervention on cognitive performance were calculated as pre- to post-intervention differences (effect scores). These scores were first correlated with children's personal characteristics: anxiety (STAIC), sex, age, BMI, IQ, and aerobic fitness. Significant correlations guided subsequent hierarchical regression models, which specifically tested for associations between the effects scores and anxiety levels while controlling for remaining relevant covariates. RESULTS:Regression analysis revealed that anxiety was a significant predictor of the effects that AAE and rest had on cognitive performance. Specifically, higher anxiety scores were associated with greater exercise-induced cognitive benefits (increased accuracy, decreased response time variability; p's < 0.05) and greater rest-induced cognitive impairments (decreased accuracy, increased response time variability; p's < 0.01). CONCLUSIONS:These findings suggest that children reporting higher trait anxiety might experience greater cognitive benefits from a single bout of AAE.