The effects of different aerobic exercise intensities on serum serotonin concentrations and their association with Stroop task performance: a randomized controlled trial
PurposeAcute exercise improves selective aspects of cognition such as executive functioning. Animal studies suggest that some effects are based on exercise induced alterations in serotonin (5 HT) secretion. This study evaluates the impact of different aerobic exercise intensities on 5 HT serum levels as well as on executive functioning considering 5 HT as a potential mediator.Methods121 young adults (23.8 3.6 years) were examined in a randomized controlled trial including three exercise intervention (35 min) groups (low intensity, 45 of the maximal heart rate (HRmax) moderate intensity, 65 HRmax; high intensity, 85 HRmax) and one control group. 5 HT levels and response inhibition (measured by a computerized Stroop test) were assessed pre and post intervention.ResultsThere was a significant (p 0.022) difference between groups regarding serum D5 HT levels. Post hoc tests indicated significant (p 0.013) higher 5 HT serum levels for the high intensity group compared to the control group while other groups did not differ significantly from each other. Serum D5 HT levels and exercise intensity were shown to be linearly associated through polynomial contrast analysis (p 0.003) Furthermore, ANOVA revealed a significant difference for Stroop parameter reading (p 0.030) and a tendency for reverse Stroop effect (p 0.061) Correlation analysis showed that augmented 5 HT levels were associated with improved results in response inhibition.ConclusionsThis study indicates that intensive acute exercise increases serum 5 HT levels compared to a control group. These findings might be relevant for many other related research fields in exercise science, since 5 HT receptors are expressed on many different cell types including endothelia and immune cells.
European Journal of Applied Physiology