The effects of a mid-morning bout of exercise on adolescents' cognitive function

Abstract

The aim of the present study was to examine the effects of a mid-morning bout of exercise on adolescents' cognitive function in a randomised crossover design where each participant completed two experimental trials. Forty-five adolescents (13.3 ± 0.3 years old), undertook a bout of exercise (ten repeats of level one of the multi-stage fitness test, 30 s rest between repeats; exercise trial) or continued to rest (resting trial). A battery of cognitive function tests assessing visuo-motor speed, executive function and working memory (visual search test, Stroop test and Sternberg paradigm, respectively) was completed 30 min before and 45 min following the exercise.Average heart rate during exercise was 172 ± 17 beats min−1. On the visual search test, there was a greater improvement in response times across the morning on the exercise trial (t = 2.6, p = 0.009). However, this improvement in response times was combined with a greater decrease in accuracy on the exercise trial (z = 2.0, p = 0.044). On the Sternberg paradigm there was a greater improvement in response times across the morning following exercise when compared to resting (t = 2.6, p = 0.010). The mid-morning bout of exercise did not affect Stroop test performance.These improvements in response times are most likely the result of a general speeding up of responses across several cognitive domains, because response times were improved similarly across two different domains and across all test complexity levels, rather than being restricted to the specific high cognitive load levels. Accordingly, exercise in school settings may help to improve cognitive function in adolescents during the school morning.