The aims of this study were (a) to determine and compare the concurrent hamstring criterion-related validity of the sit-and-reach (SR) and toe-touch (TT) tests in different athletes (tennis players, kayakers, canoeists, and cyclists); (b) to determine the criterion-related validity of the pelvic tilt assessed by the Spinal Mouse system as a measure of hamstring flexibility in athletes; and (c) to evaluate the influence of spinal posture, pelvic tilt, and hamstring muscle flexibility in the SR and TT scores. Twenty-four tennis players, 30 canoeists, 43 kayakers, and 44 cyclists were recruited. Passive straight leg raise (PSLR), SR, and TT tests were randomly performed. Spinal curvatures and pelvic tilt were evaluated with a Spinal Mouse system when the maximal trunk flexion was achieved in the SR and TT tests. Tennis players and cyclists showed moderate correlations between PSLR with respect to SR (β = 0.78 and β = 0.76, respectively) and TT (β = 0.77 and β = 0.74, respectively). Correlations were slightly lower in canoeists (SR, β = 0.64; TT, β = 0.75). Kayakers showed the lowest correlation values (SR, β = 0.53; TT, β = 0.57). Correlation values between PSLR and pelvic tilt angle in both the SR and TT tests were β < 0.70 in all the groups of athletes. Stepwise multiple regression analysis showed a high variance explained from pelvic tilt and lumbar spine in the SR score. In conclusion, the SR and TT tests can be appropriate measures to determine spine flexibility and pelvic tilt range of motion but not to evaluate the hamstring muscle flexibility in tennis players, canoeists, kayakers, and cyclists.

There is a growing interest in knowing the relationship between biological maturation and sport performance-related variables of young athletes. The objective of this study is to analyze the relationship between biological maturation, physical fitness, and kinanthropometric variables of athletes during their growing period, according to their sex. The systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement and the search protocol was registered in PROSPERO, code: CRD42020208397. A search through the PubMed, Web of Sciences, and EBSCO databases was performed. A total of 423 studies were screened and 13 were included in the meta-analysis. The meta-analysis was completed by using the mean and standard deviation of each variable according to each maturation status (early, on time, or late). Differences depending on maturation were found on physical fitness, with better results in the advanced maturational groups in the male population (standard mean difference (SMD) = 0.17–2.31; p < 0.001–0.05). Differences depending on maturation were found for kinanthropometric variables in males (SMD = 0.37–2.31; p < 0.001–0.002) and height and body mass in females (SMD = 0.96–1.19; p < 0.001). In conclusion, the early maturation group showed higher values in kinanthropometric variables and better results in physical fitness, highlighting the importance of the maturational process in the talent selection programs. Despite that, more research is needed to clarify the relationship of maturation with the other variables on female populations and the changes in the muscle and bone variables during the maturation processes of both sexes.

The revised European consensus defined sarcopenia as a progressive and generalized skeletal muscle disorder that is associated with an increased likelihood of adverse outcomes including falls, fractures, physical disability and mortality. The aim of this study was to determine the prevalence of sarcopenia and analyse the influence of diet, physical activity (PA) and obesity index as risk factors of each criteria of sarcopenia. A total of 629 European middle-aged and older adults were enrolled in this cross-sectional study. Anthropometrics were assessed. Self-reported PA and adherence to the Mediterranean diet were evaluated with the Global Physical Activity Questionnaire (GPAQ) and Prevention with Mediterranean Diet questionnaire (PREDIMED), respectively. The functional assessment included handgrip strength, lower body muscle strength, gait speed and agility/dynamic balance. Of the participants, 4.84% to 7.33% showed probable sarcopenia. Sarcopenia was confirmed in 1.16% to 2.93% of participants. Severe sarcopenia was shown by 0.86% to 1.49% of participants. Male; age group ≤65 years; lower body mass index (BMI); high levels of vigorous PA; and the consumption of more than one portion per day of red meat, hamburgers, sausages or cold cuts and/or preferential consumption of rabbit, chicken or turkey instead of beef, pork, hamburgers or sausages (OR = 0.126–0.454; all p < 0.013) resulted as protective factors, and more time of sedentary time (OR = 1.608–2.368; p = 0.032–0.041) resulted as a risk factor for some criteria of sarcopenia. In conclusion, age, diet, PA, and obesity can affect the risk of having low muscle strength, low muscle mass or low functional performance, factors connected with sarcopenia.

Background: Differences in kinanthropometric and physical fitness performance between boys and girls usually start during adolescence, as a result of the changes in the hormonal environment that occur with the advance of age and biological maturation; Methods: A total of 96 1st Regional Division players adolescent volleyball players, 48 males, (age = 14.17 ± 1.00 years-old) and 48 females (age = 14.41 ± 1.21 years-old) underwent a kinanthropometric assessment, were asked to perform different physical fitness test and to complete a questionnaire. Chronological age, maturity offset, age at peak height velocity (APHV), and birth quartile were calculated; Results: Statistical differences were observed between male and female players in the APHV (p < 0.001). Male players showed higher values in the bone and muscle-related variables (p < 0.001–0.040), as well as in the strength and power production-related physical tests (p < 0.001–0.012), while the female showed higher values in the fat-related variables (p = 0.003–0.013), and performed better in the flexibility tests. Age, maturity offset, and birth quartile showed to have statistical influence in the differences found between sex groups; Conclusions: There is a clear influence of age and biological maturation on the differences found between sexes in adolescent volleyball players that could be taken into account regarding grouping in early stages.