EFFECTS OF A PLYOMETRIC TRAINING PROGRAM WITH AND WITHOUT ADDED LOAD ON JUMPING ABILITY IN BASKETBALL PLAYERS RIADH KHLIFA, 1,2 RIDHA AOUADI, 1,2 SOUHAIL HERMASSI, 1,2 MOHAMED SOUHAIEL CHELLY, 1,2 MOHAMED CHEDLY JLID, 1,2 HAMDI HBACHA, 1 AND CARLO CASTAGNA 3 1 Research Unit ‘‘Evaluation and Analysis of Factors Influencing Sport Performance, Higher Institute of Sport and Physical Education of Ksar Said, Tunis, Tunisia; 2 Higher Institute of Sport and Physical Education of Ksar Said, Tunis, Tunisia; and 3 Degree in Sports Science and Sports, Faculty of Medicine, University of Rome ‘‘Tor Vergata’’, Rome, Italy ABSTRACT Khlifa, R, Aouadi, R, Hermassi, S, Chelly, MS, Jlid, MC, Hbacha, H, and Castagna, C. Effects of a plyometric training program with and without added load on jumping ability in basketball players. J Strength Cond Res 24(11): 2955–2961, 2010—The purpose of this investigation was to examine the effect of a standard plyometric training protocol with or without added load in improving vertical jumping ability in male basketball players. Twenty-seven players were randomly assigned to 3 groups: a control group (no plyometric training), plyometric training group (PG), and loaded plyometric group (LPG, weighted vests 10–11% body mass). Before and after the 10-week training program, all the players were tested for the 5-jump test (5JT), the squat jump (SJ), and the countermovement jump (CMJ). The PG and LPG groups performed 2 and 3 training sessions per week, during the first 3 and the last 7 weeks, respectively. The results showed that SJ, CMJ, and 5JT were significantly improved only in the PG and LPG groups. The best effects for jumps were observed in LPG (p , 0.01), which showed significantly higher gains than the PG (p , 0.05). In conclusion, it appears that loads added to standard plyometric training program may result in greater vertical and horizontal-jump performances in basketball players. KEY WORDS team sports, 5-jump test, performance, fitness training, stretch-shortening cycle, power INTRODUCTION B asketball is a multifaceted team sport that requires a well-developed anaerobic fitness to be played successfully (25). Many authors have suggested that explosive power in the form of vertical and horizontal jumps is an important characteristic for elite basketball players (16,21,34). Furthermore, vertical jump (VJ) ability has been reported to be related to elite college-players’ playing time (17). This belief was shown to be shared by the National Basketball Association strength and conditioning coaches who reported an extensive use of plyometric exercises to improve explosive-power performance in elite-level pro- fessional basketball players (17,30). Plyometric training has been proposed for the develop- ment of explosive-power performance and specifically for the improvement of VJ ability (2,23). However, only few papers addressed the use of plyometric protocols on explosive-power performance in men’s basketball (24,26). Furthermore, the published papers only addressed young basketball players selectively using drop jumps as training exercises (24,26). Additionally, no information was provided regarding the effect of plyometric training on horizontal-jump performance, an ability that has been associated with running acceleration performance in team sports (9). Luebbers et al. (22) showed that a short-term plyometric training protocol resulted in significant enhancements in VJ performance in physically active college-aged men. Recently, the Luebbers et al. (22) protocol was reported to positively affect VJ performance in well-trained soccer players (19). However, to the best of this study authors’ knowledge, no information is available on the effect of this popular plyometric training protocol in well-trained basketball players. Recently, weighted-vest jumping has shown to acutely enhance jump performance in athletic populations (8,32). However, no training studies were conducted to test the added effect of weighted plyometric exercises on jump Address correspondence to Carlo Castagna, castagnac@libero.it. 24(11)/2955–2961 Journal of Strength and Conditioning Research Ó 2010 National Strength and Conditioning Association VOLUME 24 | NUMBER 11 | NOVEMBER 2010 | 2955 Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.