The purpose of this study was to compare the effects of 3 different training protocols-plyometric training, weight training, and their combination-on selected parameters of vertical jump performance and leg strength. Forty-one men were randomly assigned to 1 of 4 groups: plyometric training (n = 11), weight training (n = 10), plyometric plus weight training (n = 10), and control (n = 10). Vertical jump, mechanical power, flight time, and maximal leg strength were measured before and after 12 weeks of training. Subjects in each training group trained 3 days per week, whereas control subjects did not participate in any training activity. Data were analyzed by a 2-way (4 [middle dot] 2) analysis of variance (repeated-measures design). Results showed that all training treatments elicited significant (p < 0.05) improvement in all tested variables. However, the combination training group produced improvements in vertical jump performance and leg strength that were significantly greater than improvements in the other 2 training groups (plyometric training and weight training). This study provides support for the use of a combination of traditional and Olympic-style weightlifting exercises and plyometric drills to improve vertical jumping ability and explosive performance in general.
(C) 2000 National Strength and Conditioning Association