You know, it’s funny I got the new NSCA journal in the mail yesterday and I was flipping through it, skimming abstracts. I noticed the following study and it made me think of this little argument that’s going on. I don’t necessarily think that squat jumps are a great exercise for athletes, but obviously some people are using them and believe them to be effective.
Comparison of Loaded and Unloaded Jump Squat Training on Strength/Power Performance in College Football Players
Jay R. Hoffman, Nicholas A. Ratamess, Joshua J. Cooper, Jie Kang, Art Chilakos, and Avery D. Faigenbaum
ABSTRACT
Hoffman, J. R., N.A. Ratamess, J.J. Cooper, J. Kang, A. Chilakos, and A. D. Faigenbaum. Comparison of loaded and unloaded jump squat training on strength/power performance in college football players. J. Strength Cond. Res. 19(4):810?815. 2005.?The purpose of this study was to explore the effects of 5 weeks of eccentrically loaded and unloaded jump squat training in experienced resistance-trained athletes during the strength/ power phase of a 15-week periodized off-season resistance training program. Forty-seven male college football players were randomly assigned to 1 of 3 groups.
One group performed the jump squat exercise using both concentric and eccentric phases of contraction (CE; n = 15). A second group performed the jump squat exercise using the concentric phase only (n = 16), and a third group did not perform the jump squat exercise and served as control (CT; n = 16). No significant differences between the groups were seen in power, vertical jump height, 40-yd sprint speed and agility performance.
In addition, no differences between the groups were seen in integrated electromyography activity during the jump squat exercise. Significant differences between the CE and CT groups were seen in ? 1RM squat (65.8 and 27.5 kg, respectively) and ? 1RM power clean (25.9 and 3.8 kg, respectively). No other between-group differences were observed. Results of this study provide evidence of the benefits of the jump squat exercise during a short-duration (5-week) training program for eliciting strength and power gains.
In addition, the eccentric phase of this ballistic movement appears to have important implications for eliciting these strength gains in college football players during an off-season training program. Thus, coaches incorporating jump squats (using both concentric and eccentric phases of contraction) in the off-season training programs of their athletes can see significant performance improvements during a relatively short duration of training.