title: In-season effect of short-term sprint and power training programs on elite junior soccer players.
abstract: The aim of this study was to examine the effects of 2 in-season short-term sprint and power training protocols on vertical countermovement jump height (with or without arms), sprint (Sprint-15m) speed, and agility (Agility-15m) speed in male elite junior soccer players. Twenty highly trained soccer players (age 18.3 +/- 0.6 years, height 177 +/- 4 cm, body mass 71.4 +/- 6.9 kg, sum skinfolds 48.1 +/- 11.4 mm), members of a professional soccer academy, were randomly allocated to either a CONTRAST (n = 10) or SPRINT (n = 10) group. The training intervention consisted of 6 supervised training sessions over 7 weeks, targeting the improvement of the players' speed and power. CONTRAST protocol consisted of alternating heavy-light resistance (15-50% body mass) with soccer-specific drills (small-sided games or technical skills). SPRINT training protocol used line 30-m sprints (2-4 sets of 4 x 30 m with 180 and 90 seconds of recovery, respectively). At baseline no difference between physical test performance was evident between the 2 groups (p > 0.05). No time x training group effect was found for any of the vertical jump and Agility-15m variables (p > 0.05). A time x training group effect was found for Sprint-15m performance with the CONTRAST group showing significantly better scores than the SPRINT group (7.23 +/- 0.18 vs. 7.09 +/- 0.20 m.s, p < 0.01). In light of these findings CONTRAST training should be preferred to line sprint training in the short term in young elite soccer players when the aim is to improve soccer-specific sprint performance (15 m) during the competitive season.
authors.affiliation: USP Araba Sport Clinic, Vitoria-Gasteiz, Basque Country, Spain.
authors.forename: Iñigo
authors.initials: I
authors.lastname: Mujika
authors.forename: Juanma
authors.initials: J
authors.lastname: Santisteban
authors.forename: Carlo
authors.initials: C
authors.lastname: Castagna
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D054874:Athletic Performance / Q000502:physiology*; D001827:Body Height; D015992:Body Mass Index; D003163:Competitive Behavior / Q000502:physiology; D005080:Exercise Test; D005163:Factor Analysis, Statistical; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D010809:Physical Fitness; D055070:Resistance Training / Q000379:methods*; D012420:Running / Q000502:physiology*; D016037:Single-Blind Method; D012885:Skinfold Thickness; D012916:Soccer / Q000502:physiology*; D013997:Time Factors