Selective serotonin reuptake inhibitors: Their effect on high-intensity exercise performance.

OBJECTIVE To determine the neuromuscular and performance effects of acute and long-term exposure to selective serotonin reuptake inhibitors (SSRIs). DESIGN Two randomized, double-blind, crossover studies. SETTING Departments of Kinesiology and Medicine, McMaster University, Hamilton, Ont, Canada. PARTICIPANTS Eleven healthy, college-aged men in the acute study; 12 healthy, college-aged men in the chronic study. INTERVENTIONS In the acute study, subjects were given a placebo and fluoxetine (40 mg) 6 hours before testing, in the chronic study, they were given fluoxetine (40mg/d) and an identical placebo for 2 weeks before testing. MAIN OUTCOME MEASURES Target measures were maximum voluntary contractions (MVCs), evoked peak torque, and percentage of motor unit activation for muscle strength and central drive. Repeated Wingate cycle ergometer tests were used to measure anaerobic power, capacity, and fatigue index. VO2max tests (80%, 90%) were used to measure time to exhaustion and cardiorespiratory responses. RESULTS In the acute study phase, MVC was lower for fluoxetine versus placebo (p =.05) and a slight fatigue resistance was measured in the repeated Wingate tests for the fluoxetine group; however, there were no affects on any other measured variable. In the chronic study phase, minute ventilation was lower for the fluoxetine trial (p <.05); however, there were no treatment affects on any of the other measurements. CONCLUSION Acute and chronic SSRI intake does not effect strength or high-intensity exercise performance in young adult men.