Comparison of anaerobic speed reserve and maximal aerobic speed methods to prescribe short format high-intensity interval training.

The purpose of the study was to compare the degree of intersubject variability in the cardiorespiratory, metabolic, and perceptual responses to high-intensity interval training (HIIT) prescribed based on the relative anaerobic speed reserve (ASR) or maximal aerobic speed (MAS) and to identify the optimal % ASR for execution of such HIIT. Seventeen male physical education students (age: 23.6 ± 1.1 years, height: 180.2 ± 5.9, body mass: 78.3 ± 8.1 kg; % body fat: 14.3 ± 2.7%) volunteered to execute three randomly scheduled 10-min HIIT exercises at 110% vVO2max , Δ15% ASR, or Δ25% ASR. Analysis of variance for repeated measures and the least significant difference post-hoc test were used to compare the physiological responses and the mean of individual residuals between the training sessions. The coefficients of variation (CV) of time spent ≥90% of maximal oxygen uptake (VO2max ) and maximal heart rate (HRmax ), peak VO2 , mean VO2 , peak HR, mean HR, blood lactate [La], and rating of perceived exertion (RPE) were 48.7%, 35.9%, 9.3%, 7%, 3.5%, 4.8%, 32%, and 16.9% during 110% vVO2max , 47.2%, 31%, 7.5%, 6.7%, 3.9%, 4.6%, 24.2%, and 14.6% during Δ15% ASR, and 48.1%, 31.5%, 7.6%, 8.4%, 3.6%, 4.1%, 20.2%, and 3.4% during Δ25% ASR session, respectively. Only the residuals in RPE were significantly (p < 0.001) higher in 110% vVO2max and Δ15% ASR in comparison to Δ25% ASR. Time spent ≥90% HRmax /VO2max was maximized during Δ15% ASR session, albeit this was not significantly different from other sessions. The ASR-based method leads to reduced CVs of physiological and perceptual responses during 10-min HIIT; however, only reductions in [La] and RPE may be considered practically meaningful. Practitioners can use vVO2max for prescription of 10-min HIIT session comprised of 15-s work and passive recovery intervals.

Physical Activity of Children and Adolescents in Croatia: A Global Matrix 4.0 Systematic Review of Its Prevalence and Associated Personal, Social, Environmental, and Policy Factors.

BACKGROUND: The previous review of physical activity (PA) among Croatian children and adolescents was conducted a decade ago. Therefore, the aim of this study was to summarize recent evidence on PA of Croatian children and adolescents and associated personal, social, environmental, and policy factors. METHODS: Eighteen experts reviewed the available evidence and provided ratings (from the lowest grade "F" to the highest grade "A+") for the 10 Global Matrix indicators. A systematic search with 100 keywords was conducted in Hrcak, PubMed/MEDLINE, Scopus, SPORTDiscus, and Web of Science for documents published from January 01, 2012, to April 15, 2022. We also conducted internet searches and secondary analyses of data (relative frequencies) from 6 studies. RESULTS: After assessing 7562 references, we included 90 publications in the review and 18 studies (83.3% of medium-to-good quality) in evidence synthesis. We found a high prevalence of insufficient PA (especially among girls) and excessive screen time (especially among boys). PA participation of children and adolescents in Croatia has declined over time. The following grades were assigned to the indicators for Croatia: B- for overall PA, C- for organized sport and PA, C for active play, C- for active transportation, D+ for sedentary behavior, inconclusive for physical fitness, D+ for family and peers, B- for school, B- for community and environment, and D+ for government. CONCLUSIONS: Coordinated actions are needed across sectors to improve PA promotion, with a focus on increasing PA among girls, reducing sedentary screen time among boys, improving parental support for PA, and further development of national PA policies.

European fitness landscape for children and adolescents: updated reference values, fitness maps and country rankings based on nearly 8 million test results from 34 countries gathered by the FitBack network.

OBJECTIVES: (1) To develop reference values for health-related fitness in European children and adolescents aged 6-18 years that are the foundation for the web-based, open-access and multilanguage fitness platform (FitBack); (2) to provide comparisons across European countries. METHODS: This study builds on a previous large fitness reference study in European youth by (1) widening the age demographic, (2) identifying the most recent and representative country-level data and (3) including national data from existing fitness surveillance and monitoring systems. We used the Assessing Levels of PHysical Activity and fitness at population level (ALPHA) test battery as it comprises tests with the highest test-retest reliability, criterion/construct validity and health-related predictive validity: the 20 m shuttle run (cardiorespiratory fitness); handgrip strength and standing long jump (muscular strength); and body height, body mass, body mass index and waist circumference (anthropometry). Percentile values were obtained using the generalised additive models for location, scale and shape method. RESULTS: A total of 7 966 693 test results from 34 countries (106 datasets) were used to develop sex-specific and age-specific percentile values. In addition, country-level rankings based on mean percentiles are provided for each fitness test, as well as an overall fitness ranking. Finally, an interactive fitness platform, including individual and group reporting and European fitness maps, is provided and freely available online (www.fitbackeurope.eu). CONCLUSION: This study discusses the major implications of fitness assessment in youth from health, educational and sport perspectives, and how the FitBack reference values and interactive web-based platform contribute to it. Fitness testing can be conducted in school and/or sport settings, and the interpreted results be integrated in the healthcare systems across Europe.

Correlation of Motor Competence and Social-Emotional Wellbeing in Preschool Children.

Introduction: The relations of motor skills to different developmental domains, i.e., cognitive, emotional, and social domain, are well-documented in research on children with poor motor competence and children with disabilities. Less conclusive evidence on interaction of motor and social or emotional development can be seen in research on typically developing children. The purpose of this study was to determine a correlation between motor skills and social-emotional functioning in typically developing preschool children and to identify differences in social-emotional functioning in children with different levels of motor competence. Methods: A total of 125 preschool children (67 boys, 58 girls, average age 5.1 years) participated in this study. To assess children's motor skills, we used the Test of Gross Motor Development-Second Edition that measures locomotor and object-control skills. To screen child's social and emotional functioning, we used the Ages and Stages Questionnaire-Social Emotional: Second Edition. Spearman's correlation analysis was used to determine association between motor skills and social-emotional functioning. Difference in social-emotional functioning between groups of preschool children with High and Low motor competences was calculated using Mann-Whitney U-test. Results: The main result of this study is weak correlation of child's motor skills to social-emotional functioning. Furthermore, preschool children with High and Low motor competences do not differ in risk for social and emotional difficulties. Conclusion: Further research on typically developing children is needed to have more conclusive evidence on interaction of motor and social or emotional development.

The Importance of Fundamental Motor Skills in Identifying Differences in Performance Levels of U10 Soccer Players.

This study examined the differences in fundamental motor skills (FMSs) and specific conditioning capacities (SCCs) between a coach's classification of first team (FT) and second team (ST) U10 soccer players and examined the most important qualities based on how the coach differentiates them. The FT (n = 12; Mage = 9.72 ± 0.41) and ST (n = 11; Mage = 9.57 ± 0.41) soccer players were assessed using the Test of Gross Motor Development-2, standing long jump, sit and reach, diverse sprints, and the 20 m multistage fitness test (MSFT). The coach's subjective evaluation of players was obtained using a questionnaire. No significant differences existed between the FT and ST in any variables (p > 0.05). However, large and moderate effect sizes were present in favour of the FT group in locomotor skills (d = 0.82 (0.08, 1.51)), gross motor quotient (d = 0.73 (0.00, 1.41)), height (d = 0.61 (-0.12, 1.29)), MSFT (d = 0.58 (-0.14, 1.25)), and maximum oxygen uptake (VO2max) (d = 0.55 (-0.17, 1.22)). Furthermore, the coach perceived the FT group as having greater technical and tactical qualities relative to ST players. This suggests that it might be more relevant for players of this age to develop good FMS connected to technical skills, before focusing on SCC. Therefore, it might be beneficial for soccer coaches to emphasize the development of FMSs due to their potential to identify talented young soccer players and because they underpin the technical soccer skills that are required for future soccer success.

Specificity of jumping, sprinting, and quick change-of-direction motor abilities.

Despite being addressed in a number of previous studies, the controversy regarding the generality vs. specificity of jumping, sprinting, and change-of-direction speed (CODS) abilities still remains unresolved. Here, we tested the hypotheses that jumping, sprinting, and CODS represent separate and specific motor abilities, and that the jumping ability based on concentric and slow stretch-shortening cycle (SSC) is relatively independent of the same ability based on fast SSC. Eighty-seven male college athletes performed 3 concentric/slow SSC and 3 fast SSC jump tests, 4 sprint tests, and 3 CODS tests. The hypotheses were tested by means of the principal component factor analysis (PCA). The applied procedure reduced the greater number of manifest variables to a smaller number of independent latent dimensions or factors and, thereafter, assessed the relationships among them. The PCA revealed a relatively simple and consistent structure consisting of 4 separate factors that explained nearly 80% of variance of the applied tests. The factors appeared to correspond to the sprinting ability, concentric/slow SSC jumping ability, fast SSC jumping ability, and CODS ability. Further analyses revealed that the extracted factors were mainly independent, because they shared only between 6 and 23% of the common variance. These results supported our hypotheses regarding the specificity of jumping, sprinting, and CODS abilities, and specificity of the concentric/slow SSC and fast SSC jumping abilities. Coaches and strength and conditioning professionals should, therefore, use separate performance tests for the assessment of the studied abilities.