Jonathan P. Farthing1 and Philip D. Chilibeck1 Contact Information
(1) College of Kinesiology, University of Saskatchewan, 105 Gymnasium Place, Saskatoon, Saskatchewan, S7N 5C2, Canada


Accepted: 7 March 2003 Published online: 17 May 2003
Abstract
The purpose of this study was to examine the effect of isokinetic eccentric (ECC) and concentric (CON) training at two velocities [fast, 180° s−1 (3.14 rad s−1) and slow,30° s−1(0.52 rad s−1)] on muscle hypertrophy. Twenty-four untrained volunteers (age 18–36 years) participated in fast- (n=13) or slow- (n=11) velocity training, where they trained one arm eccentrically for 8 weeks followed by CON training of the opposite arm for 8 weeks. Ten subjects served as controls (CNT). Subjects were tested before and after training for elbow flexor muscle thickness by sonography and isokinetic strength (Biodex). Overall, ECC training resulted in greater hypertrophy than CON training (P<0.01). No significant strength or hypertrophy changes occurred in the CNT group. ECC (180° s−1) training resulted in greater hypertrophy than CON (180° s−1) training and CON (30° s−1) training (P<0.01). ECC (30° s−1) training resulted in greater hypertrophy than CON (180° s−1) training (P<0.05), but not CON (30° s−1) training. ECC (180° s−1) training resulted in the greatest increases in strength (P<0.01). We conclude that ECC fast training is the most effective for muscle hypertrophy and strength gain.