We aimed to assess the effects of plyometric jump training (PJT) on female soccer player’s physical fitness. To this aim, a systematic review with meta-analysis (SRMA) was conducted. The electronic databases PubMed, MEDLINE, Web of Science, and SCOPUS were used. To qualify for inclusion, peer-reviewed studies must have included (i) a PJT programme of ≥2 weeks, (ii) healthy athletes, (iii) a control group, and (iv) physical fitness outcomes (e.g., jump; sprint). Studies were excluded if (i) they incorporated injuried female soccer players, (ii) did not involve PJT or an active control group, (iv) lack of baseline and/or follow-up data. Data was meta-analyzed using the inverse variance random-effects model. Ten moderate-to-high quality studies were included in the analyses, comprising 13 training groups (n = 140) and 10 control groups (n = 110). Small to large (ES = 0.60–2.24; p = 0.040 to <0.001) effects were noted for countermovement jump, drop jump, kicking performance, linear sprint, change of direction speed, and endurance. The moderator analyses (i.e., PJT duration, age groups, competitive level, and soccer experience) revealed no significant differences between groups. In conclusion, PJT may improve the physical fitness of female soccer players. Such improvements might be expected after PJT interventions with six or more weeks of duration, and in players with different chronological ages, competitive levels and soccer experience.

Sanchez-Sanchez, J, Sanchez, M, Hernandez, D, Ramirez-Campillo, R, Martínez, C, and Nakamura, FY. Fatigue in U12 Soccer-7 players during repeated 1-day tournament games—a pilot study. J Strength Cond Res 33(11): 3092–3097, 2019—The aim of this study was to describe and compare the distances and displacement speeds of U12 Soccer-7 athletes during 4 tournament Soccer-7 games (TG) played in less than 24 hours (experimental condition) with those recorded during 2 league Soccer-7 games (LG) with 24 hours of rest before the match (control condition). Ten participants (age = 10.3 ± 0.5 years) were recruited for the study. Main data analyzed during games included distance completed relative to match duration (Drel), maximal velocity, and distance completed at different running speeds (including acceleration, deceleration, standing, walking, jogging, medium-intensity running, high-intensity running, and sprinting). For data collection during games, athletes wore a global positioning system unit. Different (p ≤ 0.05) mean playing time was recorded during TG and LG (15.1 and 31.8 minutes/match, respectively). Drel during the 4 TG was maintained between 85.7 ± 8.5 and 87.5 ± 8.5 m·min⁻¹ (p > 0.05) and during the 2 LG between 84.2 ± 10.9 and 87.5 ± 9.9 m·min⁻¹ (p > 0.05). Moreover, similar Drel was recorded during TG and LG (86.8 and 85.9 m·min⁻¹, respectively). Compared with LG, during TG, maximal velocity was lower (23.0 and 21.3 km·h⁻¹, respectively; p ≤ 0.05). In addition, compared with the last game of the tournament, in the preceding games, the distance covered at low speeds (3.1–8.0 km·h⁻¹) was lower (37.7 and 32.4%, respectively; p ≤ 0.05) and at high speeds (≥18.1 km·h⁻¹) tends to be higher (2.5 and 3.3%, respectively). Therefore, compared with the control condition, accumulated Soccer-7 games with less than 24 hours of interday rest negatively affect displacement speed distribution (but not overall relative distances) in U12 Soccer-7 athletes. These results may help to better plan training and competition schedules to youth players.

The aim of this study was to analyze the association between sprint ability and endurance capacity in soccer referees. Twenty-three Spanish officials participated in this study. Each referee undertook, in this order, a 40 m linear straight sprinting test (40 m Sprint) and the Yo–Yo intermittent recovery level 1 test (YYIR1) interspersed with a 8 min of self-administered rest. The results in the 40 m Sprint test showed that the time spent by referees was 5.56 ± 0.27 s and achieved a maximum velocity of 31.46 ± 2.85 km·h⁻¹. Furthermore, during the YYIR1 the referees covered 1213.91 ± 432.26 m. The distance covered at YYIR1 was moderately correlated to the velocity achieved in the 40 m Sprint test (r = −0.404, p < 0.05). These results suggest that the ability to reach high speeds is a limiting factor in YYIR1 performance.

The aim of this study was to compare the activity profile (external loads) during soccer-7 competition versus 6 vs 6 small-sided games ( SSGs) in U12 players. Peak velocity (V_max), total distance completed (DT), total distance relative to match duration, the percentage of DT in acceleration (%DAC) and in deceleration (%DEA), and the percentage of DT at different speeds were recorded. Six types of SSGs were randomly implemented: without pitch orientation-delimitation and with a limit of three ball-contacts per player (3TOU), with no limit of ball-contacts (MAN), with a greater number of players as internal-offensive wildcard players (2WI) or external-offensive wildcard players (4WE); and with pitch orientation-delimitation and crossing the rival goal-line while dribbling the ball without goalkeepers (INV) or using official goalkeepers (GKP). The physical demands of SSGs were compared with the average of two soccer-7 match plays. During soccer-7 match plays a lower %DAC and %DEA (p < 0.05) were observed compared to 2WI, 4WE, INV and GKP, and to INV and GKP, respectively. The V_max and %HI were greater (p < 0.05) in soccer-7 match plays compared to all SSGs. In conclusion, the demands imposed on U12 players during different formats of SSGs differ from the soccer-7 match play demands, presenting a low stimulation of the actions performed at high-speed and an adequate simulation of acceleration-deceleration actions.

Keywords: football; match analysis; physiology of soccer; team sport; sports periodization

La Revista Internacional de Medicina y Ciencias de la Actividad Física y del Deporte es una revista multidisciplinar, científico-técnica, en torno a las Ciencias de la Actividad Física y del Deporte. Todos los temas son publicables siempre que estén relacionados con la actividad física y el deporte y sea explícita esta relación en el artículo.