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.

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.

To analyse the acute muscular fatigue (AMF) in triceps brachii and rectus abdominis during compression-only and standard cardiopulmonary resuscitation (CPR) performed by certified basic life support providers. Twenty-six subjects were initially recruited and randomly allocated to two study groups according to the muscles analysed; eighteen finally met the inclusion criteria (nine in each group). Both groups carried out two CPR tests (compression-only and standard CPR) of 10 min divided into five 2-min intermittent periods. The ventilation method was freely chosen by each participant (mouth-to-mouth, pocket-mask or bag-valve-mask). CPR feedback was provided all the time. AMF was measured by tensiomyography at baseline and after each 2-min period of the CPR test, in triceps brachii or rectus abdominis according to the study group. Rectus abdominis’ contraction time increased significantly during the fifth CPR period (p = 0.020). Triceps brachii’s radial muscle belly displacement (p = 0.047) and contraction velocity (p = 0.018) were lower during compression-only CPR than during standard CPR. Participants who had trained previously with feedback devices achieved better CPR quality results in both protocols. Half of participants chose bag-valve-mask to perform ventilations but attained lower significant ventilation quality than the other subjects. Compression-only CPR induces higher AMF than standard CPR. Significantly higher fatigue levels were found during the fifth CPR test period, regardless of the method. Adequate rescuer’s strength seems to be a requisite to take advantage of CPR quality feedback devices. Training should put more emphasis on the quality of ventilation during CPR.

The purpose of this study was to evaluate whether a Relative Age Effect (RAE) exists in motor competence of preschool children. The hypothesis was that motor competence, assessed by the Movement Assessment Battery for Children-2 (MABC-2), would be higher in preschool children born in the first quarter of the year compared to those who were born in the last quarter of the same year. A total of 360 preschool children were evaluated of whom 208 (57.8%) were boys and 152 (42.8%) were girls, with a mean age of 4.52 years old (± 0.50). The distribution of the participants was 172 children aged 4 years old and 188 aged 5 years old. The data showed a main effect on the age factor in the total score of aiming and catching (p < 0.001) and in the total test score (p < 0.001), in the quarter of birth factor in all the dimensions studied (i.e., total score of manual dexterity (p < 0.001); total score of aiming and catching (p = 0.001); total score of balance (p < 0.001); total test score (p < 0.001)) and in the interaction between both factors (i.e., total score of manual dexterity (p = 0.005); total score of aiming and catching (p = 0.002); total score of balance (p < 0.001); total test score (p < 0.001)). Age and quarter of birth produce a RAE in 4 and 5-year-old preschool children’s motor competence.

This study aimed to analyse the impact of high and low flexibility levels of hamstring and quadriceps muscles on physical fitness and neuromuscular properties in professional soccer players. 62 male professional soccer players participated in this study and performed 2 instrumented flexibility tests (passive straight leg raise [PSLR] and quadriceps flexibility [QF]). Anaerobic performance was assessed using countermovement jump (CMJ), Abalakov vertical jump, 20-m sprint, and Balsom agility test. A k-means cluster analysis was performed to identify a cut-off value of hamstring and quadriceps flexibility and classify players as high hamstring flexibility (HHF) and low hamstring flexibility (LHF) or high quadriceps flexibility (HQF) and low quadriceps flexibility (LQF), respectively, according to the PSLR and QF performances. The LQF players performed better than HQF on CMJ (p=0.042, ES: 0.64) and Balsom agility test (p=0.029, ES: 0.68). In addition, LQF showed higher muscular stiffness than HQF players (p=0.002, ES: 0.88). There were no significant differences between HHF and LHF groups. When pooling the HQF and LQF players’ data, the Pearson’s correlation showed significant moderate positive association between muscular stiffness and QF (r=0.516, p<0.001). These results support the rationale that baseline stiffness is likely to influence athletic performance rather than flexibility level in soccer players.

The objective of this research was to analyze the impact of an intervention program performed by a specialist in physical education (PE) to contribute to the development of motor competence (MC) in pre-school children with motor development problems. The sample consisted of 28 children (12 from the intervention group and 16 from the control group) aged between 4.1 and 5.9 years (mean = 4.71 ± 0.54) who were in the fifth and sixth grades of pre-school education in two schools from Lugo, Spain. The Movement Assessment Battery for Children-2 (MABC-2) was used for data collection. The data revealed that, in the pre- and post-test intervention groups, there are statistically significant differences in manual dexterity (p < 0.001; d = 2.63), aiming and catching (p < 0.002; d = 1.13), balance (p < 0.001; d = 1.68), total test score (p < 0.001; d = 3.30) and total percentile score (p < 0.001; d = 1.88). Between the control and intervention post-test groups, significant differences were found in manual dexterity (p = 0.015; η² = 0.22), aiming and catching (p = 0.003; η² = 0.32), balance (p = 0.050; η² = 0.15), total test score (p < 0.001; η² = 0.47) and total percentile score (p < 0.001; η² = 0.48). Based on the results obtained, a specific MC program implemented by a PE specialist contributed to the improvement of manual dexterity, aiming and catching and balance, as well as a better percentile in the general MC of pre-school children diagnosed with motor skill problems.