Comparative effectiveness of accommodating and weight resistance training modes.

Six men and six women trained the elbow flexors of both arms 3 d.wk-1 for 20 wk. In each training session, one arm did 3-5 sets of 10 maximal concentric actions on an accommodating resistance device (ARD), the other arm 3-5 sets of 8-12 coupled eccentric/concentric actions (repetitions) to volitional failure (8-12 RM) on a weight resistance device (WRD). The average "intensity" (force of concentric actions) was approximately 1.25 times greater in ARD training, the average "volume" (number of actions x force of actions) 1.6 times greater in WRD training, and the time required to complete a training session the same for each. Both types of training produced significant increases in a single maximum weight lift (1 RM on the WRD), in the peak force of a single maximal concentric action measured on the ARD and an isovelocity dynamometer, and in biceps, brachialis, and total elbow flexor cross-sectional area (CSA). Biceps Type I and II fiber area did not change significantly. WRD training produced greater increases than ARD training in the 1 RM test on the WRD and in brachialis CSA. The data indicate that both of these common training regimens effectively increase strength and muscle mass, but the weight training regimen may be more effective for increasing muscle mass.