J. Strength Cond. Res. 21(2):470-475. 2007.-The aim of the present study was to analyze the effect of whole-body vibration on energy expenditure, as well as on exercise intensity, during and immediately after a typical set of exercises for muscle hypertrophy in physically active subjects. Seventeen male university students (mean age 18.3 Ϯ 0.24 years) volunteered to perform 2 different training exercises: half squat (HS), and half squat with vibration (HSV). Both exercises were performed by all subjects on the vibration platform (with vibration only for HSV), the sequence order being assigned randomly. Energy expenditure (EE), respiratory exchange ratio, perceived exertion (PE), and heart rate were recorded for baseline, exercise, and short-recovery conditions. Training consisted of 5 sets of 10 repetitions of HS and HSV, with a 2-minute recovery interval between sets. Analysis of variance with repeated measurements and Bonferroni correction, as well as effect size were used for statistical calculations. Results indicated that EE and PE were significantly higher in the HSV group, during both exercise and recovery. Heart rate did not differ significantly between groups. Thus, it would appear that HS strength training could be rendered more energy-efficient through the addition of vibration. Moreover, it would be feasible to introduce vibration exercises into regular training programs, particularly those whose key objective is muscle hypertrophy along with fat reduction.