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This study aimed to assess the acute effect of a competitive football match on jump performance and kinematic parameters during jump landing in semiprofessional female football players. Twenty‐two semiprofessional players (20 ± 3 years) underwent a drop jump task for a posterior video analysis of the landing phase. These measurements were obtained at (1) baseline, (2) after, and (3) 48 h after a competitive football match. A one‐way ANOVA with repeated measures was employed to detect differences over the time. There was a main effect of time for maximal knee flexion angle during drop landing (p = 0.001). In comparison with baseline, maximal knee flexion angle was reduced immediately post‐match and was still reduced 48 h after the match (63.4 ± 8.6 vs 57.0 ± 11.7 vs 48.9 ± 19.1, p ≤ 0.038). There was also a main effect of time for drop jump height (p < 0.001). Drop jump height was reduced immediately post‐match and remained low 48 h after the match in comparison with baseline (27.3 ± 3.6 vs 24.5 ± 2.8 ~ 25.5 ± 3.0 cm, p ≤ 0.002). There was a main effect of time on hip flexion angle during landing (p = 0.001), but the pairwise comparison revealed that this variable was not affected immediately post‐match but was lower 48 h after the match than at baseline (50.1 ± 10.1 ~ 50.8 ± 13.2 vs 38.1 ± 17.8 °, p ≤ 0.005). A competitive football match worsened jump performance and several landing biomechanical parameters in female football players, which were still decreased in comparison with baseline even 48 h after the match. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the effectiveness of a high-intensity interval training (HIIT) intervention based on playground games (MOVI-daFit!) on improvements in adiposity, physical fitness, and cardiometabolic risk factors in schoolchildren. A cluster-randomized controlled trial (RCT) was performed that included 562 schoolchildren (9–11 years) from 10 schools in Cuenca, Spain. The intervention consisted of four 60-min sessions per week in the school setting. Analyses were conducted on the intention-to- treat basis. Changes in physical fitness parameters (cardiorespiratory fitness: main outcome), body composition, blood pressure, and biochemical cardiometabolic risk parameters were analyzed using both mixed linear and logistic regression models, controlling for baseline covariates, Tanner stages, health dietary score index, body mass index, and cluster factor school. In boys, no significant differences in any outcome measure were noted except for the standing long jump test (10.13 cm; 95% CI 2.94 to 17.32; p = 0.006) between the intervention group (IG) and the control group (CG). Improvements in mean arterial pressure (−1.68 mmHg; 95% CI −3.28 to −0.08; p = 0.039), the triglyceride/HDL-c ratio (−0.36 mg/dl; 95% CI −0.59 to −0.13; p = 0.002), C-reactive protein (−0.23 mg/L; 95% CI −0.43 to −0.03), VO2max (1.44 ml/kg/min; 95% CI 0.52 to 2.36, p = 0.002), 20-m shuttle run test (3.64 laps; 95% CI 0.51 to 6.78), and standing long jump test (7.04 cm; 95% CI 1.21 to 12.87; p = 0.018) were observed in girls in the IG compared with those in the CG. Body composition parameters did not change significantly in either boys or girls. Additionally, children with lower fitness levels obtained greater improvements than children with higher fitness levels. In conclusion, MOVI-daFit! may represent a good strategy for incorporating HIIT into playground games, although its implementation may need to be improved to extend the benefits to children and enhance its adherence. [ABSTRACT FROM AUTHOR]

We examined the association of R577X polymorphism (rs1815739) in the α-actinin-3 ( ACTN3) gene with 'explosive' leg muscle power performance in a group of male and female elite volleyball players ( n=66, 31 men, 35 women) and in a group of non-athletic male and female young adults ( n=334, 243 men, 91 women). We assessed power performance by means of the vertical squat and counter-movement jump tests. We also determined whether the genotypic frequencies of the ACTN3 R577X genotypes differed between groups. We did not observe any effect of the ACTN3 R577X polymorphism on study phenotypes in both groups, regardless of gender (all P>0.05). Genotype frequencies were similar between volleyball and control groups ( P=0.095). Moreover, we did not find an association between the ACTN3 R577X polymorphism and the likelihood of being an elite volleyball player using the dominant (RR vs RX+XX) and the recessive model (RR+RX vs XX). In summary, these findings suggest that the ACTN3 R577X polymorphism does not influence explosive leg muscle power in elite volleyball players. [ABSTRACT FROM AUTHOR]

We investigated the association between ACTN3 R577X polymorphism and jumping (vertical squat and counter-movement jump tests) and sprint ability (30 m dash) in non-athletic, healthy young adults [ N=284 (217 male), mean (SD) age: 21 (2) years]. We analyzed the differences in the study phenotypes among ACTN3 R577X genotypes by one-way analysis of covariance before and after adjusting for sex, age, weight and height (confounders). We also compared the genotype and allele frequencies between those with the best and worst results in the aforementioned tests (≥90th vs <90th of the sex-specific percentile, respectively). We used logistic regression to calculate the odds ratio (OR) for having the best performance. We did not observe a significant association between ACTN3 R577X genotypes and the study phenotypes before and after adjusting for potential confounders, nor after analyzing males and females separately. We did not observe significant differences in genotype frequencies between those with the best or the worst performance. The OR for an individual with the RR genotype to be in the top 10 percentile was <1.00 for jump tests and <1.015 for sprint tests (all P>0.05). In summary, α-actinin-3 deficiency does not negatively influence the ability to generate explosive leg muscle power in a young non-athletic population. [ABSTRACT FROM AUTHOR]