摘要：International Journal of Exercise Science 12(2): 1280-1289, 2019. The purpose of this study was to examine the acute effects of caffeine supplementation on velocity and power output during bench press and back squat exercises. Resistance trained males (n = 12) consuming less than 300 mg of caffeine daily, were recruited for this study. In a blinded crossover study design, participants supplemented with 6 mg· kg-1 caffeine or placebo (placebo, gluten-free cornstarch) 60 min prior to exercise. Participants completed 3 × 1 repetition with maximum explosive intent at 80% of their 1-RM for bench and squat exercises with two minute rest periods between each repetition. A linear position transducer was used to measure power and velocity of barbell movement. Each trial was separated by a 72 h washout period. Results indicated that mean velocity (p = 0.027; ES = 1.04) and mean power (p = 0.008; ES = 0.24) were higher during bench press exercise with caffeine versus placebo. Furthermore, mean velocity (p = 0.005; ES=1.06) and mean power (p = 0.020; ES = 0.71) values were higher for back squat exercise with caffeine versus placebo. This study suggests that caffeine ingestion imposes ergogenic benefits by increasing velocity and power in both upper and lower body resistance exercises. However, caffeine had a larger effect on lower body power output versus upper body exercise. Results may hold important implications for using caffeine during training.
