WEIGHTED-PLYOMETRIC TRAINING IS NO BETTER THAN UNWEIGHTED TRAINING
Adams, K. J., Shimp-Bowerman, J. A., Berning, J. M., Durham, M., Sevene-Adams, P. G., & Curtin, M. (2001). Plyometric training at varied resistance: Effects on vertical jump in strength trained women. Medicine and Science in Sports and Exercise, 33(5), Supplement abstract 1594.
This study investigated the effects of four weeks of plyometric vs. weighted plyometric training on vertical jump in strength-trained females N = 14). Two groups (N = 7) were formed. The plyometric group performed depth jumps, split squats, and double-leg hops with body weight twice a week. The weighted-plyometric group performed the same exercises with the addition of a weight equivalent to 20% of 1-RM in the first week, and 40% of 1-RM in the fourth week. Both groups performed 3 x 6 squats (85% 1-RM) one day per week after plyometric training.
Both groups improved vertical jump with no difference between them.
Implication. No-weight plyometric training is as effective as weighted-plyometric training.