This study investigated the effects of execution speed on measures of strength, muscular power, and hypertrophy. Eighteen male subjects trained with the half-squat exercise using an 8- to 12-RM load for 7-1/2 weeks. Eight subjects tried to produce fast concentric contractions while 10 subjects emphasized slow controlled movements. Both groups improved significantly in all measures; however, no significant differences were observed between the groups over the training period. Trends based on percentage improvements gave some support for the fast group improving more (68.7%) than the slow group (23.5%) in maximum rate of force development. The slow group improved to a greater extent (31%) that the fast group (12.4%) in absolute isometric strength, whereas the percentage gains in hypertrophy were similar for both groups. It was concluded that strength, speed-strength, and hypertrophy measures can be simultaneously developed significantly in beginning weight trainers. Beginner athletes should consider the possible effects of consciously controlling speed of contraction in weight training.
(C) 1993 National Strength and Conditioning Association