The Trainability of Adolescent Soccer Players to Brief Periodized Complex Training Chatzinikolaou, Athanasios Michaloglou, K. Avloniti, Alexandra Leontsini, D. Deli, Chariklia K. Vlachopoulos, D. Gracia Marco, Luis Andrés Arsenis, S. Athanailidis, I. Draganidis, Dimitrios Jamurtas, Athanasios Z. Williams, C. A. Fatouros, Ioannis G. Association soccer Adolescence Weight training Plyometrics Body composition Purpose: Τo investigate the effect of a complex, short-term strength/power training protocol on performance and body composition of elite early-adolescent soccer players. Methods: Twenty-two players (14-15 years) were randomly assigned to (a) an experimental (EG, n=12, participated in a 5-week training protocol with traditional multi-joint power resistance exercises, Olympic-style lifts, plyometric drills and speed work, four times/week) or (b) a control group (CG, n=10). Strength and power performance [jumping, speed, change of direction, repeated sprint ability, endurance, isokinetic strength of knee flexors and extensors, maximal strength in various lifts, speed-endurance) were evaluated pre- and post-training. Results: Cessation of training for five weeks in the CG induced a marked performance deterioration (~5-20%). Training not only prevented strength performance deterioration but also increased it (~2-30%). Endurance and RSA declined to a smaller extent in EG compared to CG (15% vs. 7.5%). Isometric strength, and body composition remained unaltered in both groups. Conclusions: Results demonstrate that (i) young players exhibit a high level of trainability of their strength/power performance (but not endurance) in response a short-term complex training protocol during early adolescence, (ii) Olympic-style lifts are characterized by increased safety in this age group and appear to be highly effective, (iii) it appears that lifts incorporating a hip thrust result in increased strength of both knee extensors and flexors, (iv) cessation of training for only five weeks results in marked deterioration of strength/power and endurance performance and (v) improvement of strength/power performance may be related to neural-based adaptation since body composition remained unaffected. 2019-05-07T09:06:38Z 2019-05-07T09:06:38Z 2018-05 journal article Chatzinikolaou A et al. The Trainability of Adolescent Soccer Players to Brief Periodized Complex Training. International Journal of Sports Physiology and Performance 2018 13:5, 645-655 [https://doi.org/10.1123/ijspp.2017-0763] http://hdl.handle.net/10481/55646 10.1123/ijspp.2017-0763 eng http://creativecommons.org/licenses/by-nc-nd/3.0/es/ open access Atribución-NoComercial-SinDerivadas 3.0 España Human Kinetics