Effects of moderate-intensity aerobic exercise on cognitive fatigue relief: a randomised self-controlled study

Although it was reported both rest and physical activity can alleviate cognitive fatigue to some extent, there is no direct scientific evidence determining which approach is more effective. This study aimed to investigate the effect of moderate-intensity aerobic exercise on the alleviation of cognitive fatigue. A 30-min TloadDback task was used to induce cognitive fatigue in 20 healthy adults, and 12-min quiet rest and moderate-intensity aerobic exercise were performed in random order. During the cognitive task, standard deviation of the NN interval (SDNN), total frequency (TP, 0–0.4 Hz) and very low frequency (VLF, 0–0.15 Hz) of heart rate variability increased significantly. The blink duration and number, fixation number, saccade amplitude and number increased significantly with time, while fixation duration and pupil size decreased significantly. After 12-min intervention protocols, the participants' feeling of fatigue, vigour and boredom recovered significantly. The recovery of fixation duration was better after quiet rest, while the pupil size was significantly larger after aerobic exercise. It was found that both quiet rest and aerobic exercise can alleviate cognitive fatigue, but aerobic exercise may be more effective in the recovery of arousal levels.