An Acute Alcoholic Beer Dose Impaired Exercise Performance: A Double-Blind, Placebo-Controlled Crossover Trial.

Abstract

Purpose: We investigated whether a small dose of alcoholic beer ingested before a running exercise bout impaired performance and changed psychophysiological responses to exercise.

Methods: After three sessions of familiarizations, 16 healthy and physically active men (25.8 ± 5.1 years, 175.0 ± 5.4 cm, and 76 ± 6.5 kg) performed a 30-min running time trial in a double-blind and placebo-controlled crossover design, after ingesting either beer (alcohol 4.8% v/v; 0.3 g/kg) or nonalcoholic beer (placebo). Performance, cardiopulmonary (oxygen consumption, ventilation, respiratory exchange ratio, and heart rate), and perceptual (perceived exertion, affect, and motivation) variables were assessed throughout the trial and averaged every 5 min during exercise. Running economy was assessed during steady-state running at 8 km/hr. The data were analyzed through t tests and repeated-measures mixed models (p < .05).

Results: The ingestion of beer significantly decreased the average speed by 4.7% (p = .04; d = 0.21) and total distance covered by 4.3% (p = .007; d = 0.26) when compared with placebo. The ingestion of beer also impaired the running economy by 1.1% (p = .01; d = 0.39) and increased respiratory exchange ratio throughout the exercise bout (p = .004, d = 1.07). No beer-by-time interaction effects were detected in cardiopulmonary outcomes (p > .05).

Conclusions: A small dose of alcoholic beer reduced the exercise capacity of healthy individuals, likely due to an impairment in running economy.