The Acute Effects of a Single Bout of Moderate-intensity Aerobic Exercise on Cognitive Functions in Healthy Adult Males

Abstract

Single acute bouts of moderately-intense aerobic exercise like walking have been found to improve cognitive control of attention in children, but some studies have reported no improvement in cognitive flexibility following acute aerobic exercise. Submaximal aerobic exercise performed for 60 minutes facilitated specific aspects of information processing in adults but extended exercises leading to dehydration compromised both information processing and memory functions. Improvement in executive functions has also been reported during cycling at 70% of Heart Rate Reserve (HRR) across young and older age groups. However, there are studies which have reported no correlation between physical activity and academic performance in children and a recent systematic review of 30 relevant studies reported no significant improvement in cognition with physical activity or exercise in adults. There seems to be lack of consensus on the effect of exercise on cognition, which may be because the exercise protocols used and cognitive functions tested by different researchers were not uniform. The primary aim of this study was to investigate the acute effects of aerobic exercise across different cognitive domains in healthy young individuals. A homogeneous group of 10 right handed healthy adult males participated in the study and was subjected to 8 cognitive function tests including 2 tests each across the four categories: Memory, Reasoning, Concentration and Planning using a pre-validated web based tool. Following baseline testing, subjects performed 30 minutes' of cycling on a stationary bicycle ergometer at moderate intensity (60-70% of HRR). Post-test scores were recorded when heart rate returned to within 10% of baseline. Pre and post-test scores were compared using the paired t-test. After exercise, there was significant improvement (Mean ± SD) in the Paired Associates (4.8±1.0 Vs 5.5 ± 1.0), Odd One Out (10.5 ± 3.0 Vs 13 ± 3.1) and Spatial Slider test (30.4 ± 17.8 Vs 40.5 ± 13.9), the tests of Memory, Reasoning and Planning respectively. No significant improvement was found for concentration. Total post-test time was significantly lower than the pre-test time (23.5 ± 2.55 Vs 21.2 ± 1.48 minutes). A single bout of moderate intensity aerobic exercise for as less as 30 minutes can improve some aspects of cognition, most prominently for memory, reasoning and planning and can shorten the time taken to complete the tests.