Increased cerebral blood flow among adolescents with bipolar disorder at rest is reduced following acute aerobic exercise 2016 Highlights • Measured cerebral blood flow (CBF) at baseline and after recumbent cycling. • Baseline frontal CBF was increased in adolescents with bipolar disorder compared to controls. • Acute exercise decreased CBF more dramatically in adolescents with bipolar disorder. • Exercise-related CBF change was associated with feelings of exhaustion. Abstract Objective Cerebral blood flow (CBF) is altered in mood disorders but has not been examined among adolescents with bipolar disorder (BD). Similarly, little is known about the acute neurophysiologic effects of aerobic exercise in BD. We therefore compared CBF between adolescents with and without BD at rest and acutely following a single exercise session. Methods Thirty-one adolescents with BD and 20 age and sex-matched controls participated in this study. CBF magnetic resonance images (MRI) were acquired using arterial spin labeling at a baseline as well as 15 and 45 min after a single 20-min session of recumbent cycling. Voxel-based CBF analyses compared groups at baseline and after exercise. Clinical, body mass index (BMI) and exercise-induced feelings inventory (EFI) data were examined for their influence on CBF findings. Results Baseline CBF was increased in medial frontal and middle cingulate regions in BD compared to controls. Analysis of the acute CBF changes revealed pronounced exercise-related decreases in CBF in BD. Exercise-related feelings of exhaustion were associated with CBF changes in frontal but not parietal regions. Discussion A single bout of moderate-intensity aerobic exercise reduced regional CBF to a greater extent in BD compared to controls; these time dependent CBF responses were associated with exercise-induced feelings of exhaustion.