The Effect of Unilateral Concentric Weight Training and Detraining on Joint Angle Specificity, Cross-Training, and the Bilateral Deficit

Joseph P. Weir, Dona J. Housh, Terry J. Housh, Loree L. Weir

Changes in strength following concentric-only weight training and detraining are poorly understood. The purpose of this investigation was to examine the effects of unilateral concentric leg extension weight training and detraining on joint angle specificity, cross-training, and the bilateral deficit (individual limb strength > bilateral strength / 2). Sixteen males volunteered to be subjects for this investigation (concentric training group, N = 8; control group, N = 8). The training group performed 8 weeks of training with the nondominant limb 3 times per week (3-5 sets x 6 repetitions), followed by 8 weeks of detraining. These subjects were tested pretraining, posttraining, and following detraining for maximal isometric strength at 3 joint angles (15, 45, and 75°) in both limbs as well as for the 1-repetition maximum (1-RM) concentric strength of the trained limb, untrained limb, and bilaterally. The results of this investigation indicated that the effects of the concentric weight training were not joint angle specific as the isometric strength increases occurred at all 3 joint angles. This effect was found in both limbs, indicating that cross-training occurred. The results of the 1-RM analyses showed that initially there was a bilateral deficit (untrained limb > bilateral, trained limb at pretraining). While the concentric training resulted in increases in 1-RM strength in the trained limb, untrained limb, and bilaterally, differences between bilateral strength and the untrained limb were reversed posttraining and the trained limb values exceeded both the bilateral and untrained limb values. Finally, the effects of detraining were more pronounced for isometric strength vs. 1-RM strength as there was a significant decrease from posttraining in the isometric scores, but the detraining 1-RM values were not significantly decreased from posttraining for either limb or bilaterally.

J Orthop Sports Phys Ther. 1997;25(4):264-270.

Key Words: knee, muscle, dynamic strength, exercise training

View Full Article