Changes in EEG Activity during Exercise

Abstract

Few studies have systematically examined changes in brain electrical activity during an acute bout of exercise. Those that have studied changes during exercise have often found an increase in power in the alpha and beta frequency. PURPOSE: To investigate whether the increases in brain activity occur because of an increase in exercise intensity or an accumulation due to the duration of the exercise. METHODS: 30 males (Age = 22.5 ± 3.5 years; Height = 181.1 ± 7.2 cm; Weight = 83.7 ± 17.8 kg) participated in the study. Participants cycled on a recumbent cycle ergometer for 5, 5 min stages for a total of 25 min. The first stage was 50 W; the next 4 stages were randomly assigned at 50W, 100W, 150W or 200W. Brain activity was recorded via EEG (24 lead, PS YLAB EEG System, Contact Precision Instruments, Cambridge, MA) pre-exercise, at the end of each stage of exercise, immediate post exercise (IPE), and 10 min post-exercise. EEG signals were visually inspected for artifact and underwent a Fast Fourier Transform to determine power at the alpha 1 (8.00–10.49 Hz), alpha 2 (10.50–12.99), beta 1 (13.00–17.99 Hz), and beta 2 (18.00–30.00) frequency bands. RESULTS: ANOVA analyses revealed a significant effect for intensity (p <.001) for all EEG frequencies, alpha 1, alpha 2, beta 1 and beta 2. Compared to baseline levels, EEG power for the frequencies increased as exercise intensity increased and returned back to near baseline levels at 10-min post exercise. When running analyses based on the different stages, regardless of intensity, an effect for stage (p <.001) was also seen when compared to baseline levels with increased EEG power during the exercise session. CONCLUSIONS: It appears that the increase in alpha and beta power during exercise may be due to both an accumulation of duration as well as intensity. Future studies should continue to examine the influence of intensity and duration on changes in brain activity. These changes may be important in explaining perceptual, affective and cognitive responses to exercise.