NORMAN, Okla.—Consumption of a low-calorie energy drink may improve physiological adaptations to strength training, according to a new study (J Strength Cond Res. 2010;24(8):2227-38. DOI: 10.1519/JSC.0b013e3181aeb0cf). Researchers from the Human Performance Laboratory, Department of Health and Exercise Science at the University of Oklahoma, assessed the effects of daily consumption of an energy drink alone or with exercise on measures of body composition, cardiorespiratory fitness, strength, mood and safety in previously sedentary males. A total of 38 men were recruited for the 10-week study and randomly assigned to energy drink + exercise (EX-A), energy drink (NEX-A), placebo + exercise (EX-B) or placebo (NEX-B). Subjects in the exercise group participated in resistance and endurance exercise.
No significant changes were observed for body composition, fitness or strength in NEX-A. Subjects in the EX-A group had significantly greater decreases in fat mass and percentage body fat, and increases in VO2peak, compared to the EX-B group. Also, ventilator threshold (VT), minute ventilation, VO2 at VT and power output at VT improved significantly from baseline to study’s end in the EX-A subjects, but not in any of the other three groups. No adverse effects on hepatic, renal, cardiovascular or immune function were seen in men drinking the energy drink daily; energy drink consumption also had no effect on mood.
