Nutrients, Vol. 18, Pages 798: Acute Effects of Different Melatonin Doses on Performance and Psychophysiological Responses During Exhaustive Cycling Exercise: A Double-Blind Crossover Study
Nutrients doi: 10.3390/nu18050798
Authors:
Larissa de Castro Pedroso
Maria Clara dos Reis
Vanessa Bertolucci
Luana Alves Silva
Ivan Gustavo Masselli dos Reis
Wladimir Rafael Beck
Pedro Paulo Menezes Scariot
Leonardo Henrique Dalcheco Messias
Background/Objectives: This study examined the acute effects of different doses of melatonin on performance, physiological, and psychophysiological responses during individualized exhaustive cycling exercise. Methods: Fifteen physically active but cycling-inexperienced men (18–35 years) completed a double-blind, randomized, placebo-controlled, crossover protocol. Following an incremental test to determine the anaerobic threshold (AnT), participants performed four exhaustive exercise sessions at 80% of AnT after ingesting placebo or melatonin (5, 12.5, or 20 mg), administered approximately 30 min before exercise. Time to exhaustion (TLim) was considered the primary performance outcome. Heart rate, peripheral oxygen saturation, blood lactate concentration, blood glucose, and ratings of perceived exertion were assessed before, during, and after exercise. Results: No significant differences were observed between experimental conditions for TLim or for any physiological or psychophysiological variable. Only main effects of time were detected, reflecting expected exercise-induced responses, with small effect sizes and no evidence of a dose–response relationship across melatonin conditions. Baseline values were comparable among sessions. These findings indicate that acute melatonin administration at doses ranging from 5 to 20 mg does not elicit ergogenic effects nor modulate physiological or psychophysiological responses during prolonged individualized cycling exercise in healthy individuals. Conclusions: In male, healthy, physically active individuals inexperienced in cycling, acute melatonin administration at the doses tested did not produce ergogenic effects or alter physiological and psychophysiological responses during prolonged, individualized cycling exercise.
Background/Objectives: This study examined the acute effects of different doses of melatonin on performance, physiological, and psychophysiological responses during individualized exhaustive cycling exercise. Methods: Fifteen physically active but cycling-inexperienced men (18–35 years) completed a double-blind, randomized, placebo-controlled, crossover protocol. Following an incremental test to determine the anaerobic threshold (AnT), participants performed four exhaustive exercise sessions at 80% of AnT after ingesting placebo or melatonin (5, 12.5, or 20 mg), administered approximately 30 min before exercise. Time to exhaustion (TLim) was considered the primary performance outcome. Heart rate, peripheral oxygen saturation, blood lactate concentration, blood glucose, and ratings of perceived exertion were assessed before, during, and after exercise. Results: No significant differences were observed between experimental conditions for TLim or for any physiological or psychophysiological variable. Only main effects of time were detected, reflecting expected exercise-induced responses, with small effect sizes and no evidence of a dose–response relationship across melatonin conditions. Baseline values were comparable among sessions. These findings indicate that acute melatonin administration at doses ranging from 5 to 20 mg does not elicit ergogenic effects nor modulate physiological or psychophysiological responses during prolonged individualized cycling exercise in healthy individuals. Conclusions: In male, healthy, physically active individuals inexperienced in cycling, acute melatonin administration at the doses tested did not produce ergogenic effects or alter physiological and psychophysiological responses during prolonged, individualized cycling exercise. Read More