Dose response effects of a caffeine-containing energy drink on muscle performance: A repeated measures design

Background: energy drinks have become the most used caffeine-containing beverages in the sport setting. the aim of this study was to determine the effects of two doses of a caffeine-containing energy drink on muscle performance during upper- and lower-body power-load tests.methods: in a randomized order,twelve active participants ingested 1 and 3 mg of caffeine per kg of body weight using a commercially available energy drink (fure®,proenergetics) or the same drink without caffeine (placebo; 0 mg/kg). after sixty minutes,resting metabolic rate,heart rate and blood pressure were determined. then,half-squat and bench-press power production with loads from 10 to 100% of 1 repetition maximum was determined using a rotator encoder.results: in comparison to the placebo,the ingestion of the caffeinated drink increased mean arterial pressure (82 ± 7 < 88 ± 8 ≈ 90 ± 6 mmhg for 0 mg/kg,1 mg/kg,3 mg/kg of caffeine,respectively; p < 0.05) and heart rate (57 ± 7 < 59 ± 8 < 62 ± 8 beats/min,respectively; p < 0.05) at rest in a dose response manner,though it did not affect resting metabolic rate. while the ingestion of 1 mg/kg of caffeine did not affect maximal power during the power-load tests with respect to the placebo,3 mg/kg increased maximal power in the half-squat (2554 ± 167 ≈ 2549 ± 161 < 2726 ± 167 w,respectively; p < 0.05) and bench-press actions (349 ± 34 ≈ 358 ± 35 < 375 ± 33 w,respectively; p < 0.05).conclusions: a caffeine dose of at least 3 mg/kg in the form of an energy drink is necessary to significantly improve half-squat and bench-press maximal muscle power. © 2012 del coso et al.; licensee biomed central ltd.