title: Effects of in-season low-volume high-intensity plyometric training on explosive actions and endurance of young soccer players.
abstract: Integrating specific training methods to improve explosive actions and endurance in youth soccer is an essential part of players' development. This study investigated the efficiency of short-term vertical plyometric training program within soccer practice to improve both explosive actions and endurance in young soccer players. Seventy-six players were recruited and assigned either to a training group (TG; n = 38; 13.2 ± 1.8 years) or a control group (CG; n = 38; 13.2 ± 1.8 years) group. All players trained twice per week, but the TG followed a 7-week plyometric program implemented within soccer practice, whereas the CG followed regular practice. Twenty-meter sprint time (20-m), Illinois agility test time, countermovement jump (CMJ) height, 20- (RSI20) and 40- (RSI40) cm drop jump reactive strength index, multiple 5 bounds distance (MB5), maximal kicking test for distance (MKD), and 2.4-km time trial were measured before and after the 7-week period. Plyometric training induced significant (p ≤ 0.05) and small to moderate standardized effect (SE) improvement in the CMJ (4.3%; SE = 0.20), RSI20 (22%; SE = 0.57), RSI40 (16%; SE = 0.37), MB5 (4.1%; SE = 0.28), Illinois agility test time (-3.5%, SE = -0.26), MKD (14%; SE = 0.53), 2.4-km time trial (-1.9%; SE = -0.27) performances but had a trivial and nonsignificant effect on 20-m sprint time (-0.4%; SE = -0.03). No significant improvements were found in the CG. An integrated vertical plyometric program within the regular soccer practice can substitute soccer drills to improve most explosive actions and endurance, but horizontal exercises should also be included to enhance sprinting performance.
authors.affiliation: 1Department of Physical Activity Sciences, University of Los Lagos, Osorno, Chile; 2Canadian Sport Institute Pacific, Vancouver, Canada; 3Canadian Soccer Association, Ottawa, Canada; 4Family Health Center of Los Lagos, Health Promotion Program, Los Lagos, Chile; 5Laboratory of Exercise Sciences, MEDS Clinic, Santiago, Chile; 6Physical Education Department, University of La Frontera, Temuco, Chile; 7Laboratory of Physiology, Department of Biological Science, Faculty of Biological Sciences, Andrés Bello University, Viña del Mar, Chile; 8Kinesiology School, Faculty of Rehabilitation Sciences, Andrés Bello University, Viña del Mar, Chile; 9Cellular Physiology Laboratory, Biomedical Department, Faculty of Health Science, University of Antofagasta, Antofagasta, Chile; and 10Department of Health Sciences, Public University of Navarre, Tudela, Spain.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Ramírez-Campillo
authors.forename: César
authors.initials: C
authors.lastname: Meylan
authors.forename: Cristian
authors.initials: C
authors.lastname: Alvarez
authors.forename: Carlos
authors.initials: C
authors.lastname: Henríquez-Olguín
authors.forename: Cristian
authors.initials: C
authors.lastname: Martínez
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Cañas-Jamett
authors.forename: David C
authors.initials: DC
authors.lastname: Andrade
authors.forename: Mikel
authors.initials: M
authors.lastname: Izquierdo
mesh_terms: D000293:Adolescent; D054874:Athletic Performance / Q000502:physiology; D002648:Child; D005080:Exercise Test; D006801:Humans; D008297:Male; D009048:Motor Skills / Q000502:physiology; D064797:Physical Conditioning, Human / Q000379:methods* / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D059385:Plyometric Exercise / Q000379:methods*; D012420:Running / Q000502:physiology; D012916:Soccer / Q000502:physiology*; D013997:Time Factors