The aim of this study was to assess the effect of core strength training performed on a stable surface (CTS) compared with core strength training performed on an unstable surface (CTU) on physical fitness (jump performance, sprint, and repeated sprint ability (RSA)) and quality of movement (Fundamental Movement Screen) in professional female futsal players. Fourteen professional female futsal players (mean age: 23.7 ± 5.1 years, age range: 18-28 years) were randomly assigned to a CTS (n = 7) or a CTU (n = 7) group. The intervention program was carried out 3 times a week over 6 weeks. Players of both groups performed the same four core-strengthening exercises. The only difference between the two interventions was that the CTU group performed all exercises (i.e., shoulder bridge, side bridge, prone plank, and crunch) on an unstable surface (Togu® Dyn-Air). Within-group analysis showed significant improvements (p < 0.001) in 10 m sprint performance from the pre- to post-test in the CTS (+4.37%) and CTU (+5.00%) groups. Players in both the CTS (+10.39%) and CTU (+11.10%) group also showed significant enhancement in the Functional Movement Screen total score, from the pre-test to post-test. In addition, a significant time effect was also observed for the CTU group in the relative score of the RSA test decreasing from the pre- to post-test (-30.85%). In the between-groups analysis, there were no significant differences between the core strength training groups (CTS vs CTU) in any variable. To conclude, sprint and Functional Movement Screen performance improved following CTS and CTU when conducted in combination with regular futsal training. In addition, CTU had limited benefit in RSA compared to CTS.

The aim of this study was to evaluate the differences on motor competence between 5-year-old boys and girls and to investigate the existence of Relative Age Effect (RAE) on their motor competence. A total of 232 preschool children were evaluated of whom 134 (57.8%) were boys and 98 (42.2%) were girls. The Movement Assessment Battery for Children-2 (MABC-2) was used to collect data. The data show a main effect on gender factor; there was a main effect in total score of manual dexterity (MD; p = 0.010), in total score of balance (Bal; p < 0.001), in total test score (TTS; p < 0.001), and in total percentile score (TPS, p < 0.001). In the semester of birth factor, there were differences in aiming and catching (A&C, p < 0.001), in Bal (p = 0.029) and in total percentile score (TPS, p = 0.010). Girls perform better in MD, Bal, TTS, and TPS than boys. Preschool children born in the first semester obtain, in general, a higher percentage and a higher percentile than their peers born in the second one. RAE is present in A&C, Bal, and TPS, with higher scores obtained by preschool children born in the first semester compared to those born in the second one.

Context: Plyometric training promotes a highly effective neuromuscular stimulus to improve running performance. Jumping rope (JR) involves mainly foot muscles and joints, due to the quick rebounds, and it might be considered a type of plyometric training for improving power and stiffness, some of the key factors for endurance-running performance. Purpose: To determine the effectiveness of JR during the warm-up routine of amateur endurance runners on jumping performance, reactivity, arch stiffness, and 3-km time-trial performance. Methods: Athletes were randomly assigned to an experimental (n = 51) or control (n = 45) group. Those from the control group were asked to maintain their training routines, while athletes from the experimental group had to modify their warm-up routines, including JR (2–4 sessions/wk, with a total time of 10–20 min/wk) for 10 weeks. Physical tests were performed before (pretest) and after (posttest) the intervention period and included jumping performance (countermovement-jump, squat-jump, and drop-jump tests), foot-arch stiffness, and 3-km time-trial performance. Reactive strength index (RSI) was calculated from a 30-cm drop jump. Results: The 2 × 2 analysis of variance showed significant pre–post differences in all dependent variables (P < .001) for the experimental group. No significant changes were reported in the control group (all P ≥ .05). Pearson correlation analysis revealed a significant relationship between Δ3-km time trial and ΔRSI (r = −.481; P < .001) and ΔStiffness (r = −.336; P < .01). The linear-regression analysis showed that Δ3-km time trial was associated with ΔRSI and ΔStiffness (R2 = .394; P < .001). Conclusions: Compared with a control warm-up routine prior to endurance-running training, 10 weeks (2–4 times/wk) of JR training, in place of 5 minutes of regular warm-up activities, was effective in improving 3-km time-trial performance, jumping ability, RSI, and arch stiffness in amateur endurance runners. Improvements in RSI and arch stiffness were associated with improvements in 3-km time-trial performance.

The objective of this study was to verify the occurrence and effect size of relative age effect in professional futsal players, by observing how its presence and impact change according to the season, team level and player position. The sample was composed of 1873 professional futsal players who played in the First Division of the Spanish National Futsal League between seasons 2006-2007 and 2014-2015. The players’ birthdates were divided into quarters (Q1, Q2, Q3 and Q4). A relative age effect reversal was observed in the professional futsal players for the nine analyzed seasons. A relative age reversal effect was observed in high and medium level teams. Finally, a relative age effect reversal was also found for the goalkeeper and pivot positions. The results could suggest that players that initially experienced maturity disadvantages in major sports, can have a second chance to emerge in professional minor sports (i.e. futsal vs. soccer). However, the underlying mechanisms why a reversal occurs are still unclear, and more studies focusing on the mediators of the effect are needed.

No abstract

The aims of this study were to describe the external and internal workloads in a professional female futsal team during a whole season and to compare workloads during different periods of the season. Ten professional female futsal players (age 22.8 ± 4.3 years; 5.1 ± 2.4 years of experience; weight 61.9 ± 7.1 kg; height 1.66 ± 0.06 m) participated voluntarily in this study during the whole season. The internal workload was measured by the session-Rate of perceived exertion (session-RPE) method, while the external workload was indirectly measured by considering the training and match volume and the type of contents of each session over 43 weeks. Mean sRPE throughout the season was 319.9 ± 127.1 arbitrary units (AU). Higher internal loads (total weekly training load and strain) were reported during the pre-season compared with the in-season mesocycles (p < 0.05); meanwhile, the fifth to eighth mesocycles of the in-season showed an oscillatory pattern. Finally, Monday was the most-demanding session during the in-season period over the Thursday (p < 0.05; effect size: 1.33) followed by match day, meanwhile no statistical differences were reported during different sessions of the pre-season microcycle (p > 0.05). This study suggests that microcycles of pre-season present a stable load pattern, meanwhile workloads during the in-season period report a tapering strategy in a professional female futsal team.

Injuries are one of the worst case scenarios for an athlete and a team. The aim of this study was to analyze the injury incidence, characteristics and burden among a cohort of elite female futsal players. A prospective cohort study was designed over a season. Eighty-nine players from seven elite female futsal teams were monitored during the whole season. Eight different variables were recorded when an injury happened, as well as exposure time. A total of 90 injuries were recorded so that 54 out of 89 players (60.6%) sustained an injury. The overall injury incidence was 5 injuries per 1000 h of futsal play exposure. Moderate injuries were the most frequent (1.7 injuries per 1000 h of futsal play exposure). The quadriceps and ankle were the regions where most injuries occurred. Contact injuries were more common during matches than training, and usually happened at the end of the season. Elite female futsal players are exposed to a substantial injury risk, especially on ankle and quadriceps with moderate severity, occurring at the end of the sessions, especially during matches. These results highlight the need of new preventive strategies to reduce the high injury incidence in female futsal players.

The aim of this study was to examine the effects of the menstrual cycle on vertical jumping, sprint performance and force-velocity profiling in resistance-trained women. A group of resistance-trained eumenorrheic women (n = 9) were tested in three phases over the menstrual cycle: bleeding phase, follicular phase, and luteal phase (i.e., days 1–3, 7–10, and 19–21 of the cycle, respectively). Each testing phase consisted of a battery of jumping tests (i.e., squat jump [SJ], countermovement jump [CMJ], drop jump from a 30 cm box [DJ30], and the reactive strength index) and 30 m sprint running test. Two different applications for smartphone (My Jump 2 and My Sprint) were used to record the jumping and sprinting trials, respectively, at high speed (240 fps). The repeated measures ANOVA reported no significant differences (p ≥ 0.05, ES < 0.25) in CMJ, DJ30, reactive strength index and sprint times between the different phases of the menstrual cycle. A greater SJ height performance was observed during the follicular phase compared to the bleeding phase (p = 0.033, ES = −0.22). No differences (p ≥ 0.05, ES < 0.45) were found in the CMJ and sprint force-velocity profile over the different phases of the menstrual cycle. Vertical jump, sprint performance and the force-velocity profiling remain constant in trained women, regardless of the phase of the menstrual cycle.