THE EFFECTS OF BUSPIRONE ON PERCEIVED EXERTION AND TIME TO FATIGUE INMAN

Male subjects exercised at 80% maximal rate of O-2 uptake (V(over dot) (O2,max)) following Oral administration of either placebo or the parti al 5-HT1A agonist buspirone (45 mg), using a paired design. Ratings of perceived exertion were higher following buspirone and time to voliti onal fatigue (median and inter-quartile range) fell significantly by a pproximately a third from 26 min (24-30 min) on placebo to 16 min (11- 19 min) following buspirone. Serum prolactin was significantly elevate d following buspirone administration, indicating increased hypothalami c 5-HT1A receptor stimulation. There were no significant differences i n blood lactate or serum glucose between the trials. This study suppor ts the possible central modulation of exercise tolerance by serotonerg ic pathways, although a role for dopamine cannot be excluded.