Effects of 20-Minute Intensive Exercise on Subjects with Different Working Memory Bases

Continuous moderate-intensity aerobic exercise improves cognitive function including working memory (WM). We aimed to determine the differences in the effects of exercise on WM based on pre-exercise WM function and oxyhemoglobin (O₂Hb) changes. We enrolled 12 healthy adult males who, after a 4-min rest and warm-up, performed a 20-min exercise regime at a workload corresponding to 50% of maximal oxygen consumption. They performed a pre- and postexercise two-back test, and the reaction times were recorded. Near-infrared spectroscopy was used to monitor the O₂Hb concentration in the left prefrontal cortex during the exercise. Based on the pre-exercise reaction time, the subjects were allocated into either a fast group (FG) or a slow group (SG). The pre- and postexercise changes in the reaction time and time-to-peak O₂Hb were compared. Further, we determined the relationship between the change in the reaction time and time-to-peak O₂Hb. There was no significant change in the reaction time of the FG; however, that in the SG decreased significantly. The time-to-peak O₂Hb in the FG was significantly less than that in the SG. These results showed differences in the changes of reaction time and O₂Hb changes between the FG and SG.