Prevalence of meeting 24-Hour Movement Guidelines from pre-school to adolescence: A systematic review and meta-analysis including 387,437 participants and 23 countries

Background:Meeting the 24-Hour Movement Guidelines(physical activity,screen time,and sleep duration) has been associated with positive health indicators.However,there are no previous meta-analyses that have examined the overall adherence to the 24-Hour Movement Guidelines from pre-school to adolescence across the world.Therefore,the main purpose of this systematic review and meta-analysis was to examine the overall(non)adherence to the 24-Hour Movement Guidelines among preschoolers,children,and adolescents worldwide.Methods:Four electronic databases(MEDLINE,Scopus,Web of Science,and Cochrane Database of Systematic Reviews) were searched for quantitative studies published in Spanish and English between January 2016 and May 2021.Studies that were conducted with apparently healthy participants and reported the overall(non)adherence to the 24-Hour Movement Guidelines in preschoolers and/or children and/or adolescents were included.Results:Sixty-three studies comprising 387,437 individuals(51% girls) aged 3-18 years from 23 countries were included.Overall,7.12%(95%confidence interval(95%CI):6.45%-7.78%) of youth met all three 24-Hour Movement Guidelines,and 19.21%(95%CI:16.73%-21.69%)met none of the 3 recommendations.Concerning sex,adherence to all recommendations was significantly lower in girls(3.75%,95%CI:3.23%-4.27%) than in boys(6.89%,95%CI:5.89%-7.89%)(p <0.001).However,there were no sex differences regarding adherence to any of the 3 individual recommendations(girls,15.66%,95%CI:8.40%-22.92%;boys,12.95%,95%CI:6.57%-19.33%).In terms of age group,adherence to the 3 recommendations was 11.26%(95%CI:8.68%-13.84%),10.31%(95%CI:7.49%-13.12%),and 2.68%(95%CI:1.78%-3.58%) in preschoolers,children,and adolescents,respectively.Conversely,8.81%(95%CI:5.97%-11.64%) of preschoolers,15.57%(95%CI:11.60%-19.54%) of children,and 28.59%(95%CI:22.42%-34.75%) of adolescents did not meet any of the recommendations.South America was the region with the lowest adherence(all:2.93%;none:31.72%).Overall adherence to the 24-Hour Movement Guidelines was positively related to country Human Development Index(β=-0.37,95%CI:-0.65 to-0.09;p=0.010).Conclusion:Most young people fail to meet the three 24-Hour Movement Guidelines,particularly adolescents,girls,and those who are from countries with a lower Human Development Index.Moreover,1 in 5 young people did not meet any of these recommendations.Therefore,these results highlight the need to develop age-and sex-specific strategies to promote these movement behaviors from the early stages of life.

Epidemiology of injuries in male and female youth football players:A systematic review and meta-analysis

Background:To conduct a systematic review and meta-analysis of epidemiological data of injuries in male and female youth football players.Methods:Searches were performed in MEDLINE/PubMed,Web of Science,Cochrane Library,and SPORTDiscus databases.Studies were considered if they reported injury incidence rate in male and female youth(≤19 years old)football players.Two reviewers(FJRP and ALV)extracted data and assessed trial quality using the Strengthening the Reporting of Observational Studies in Epidemiology(STROBE)statement and the Newcastle Ottawa Scale.The Grading of Recommendations Assessment,Development,and Evaluation approach determined the quality of evidence.Studies were combined using a Poisson random effects regression model.Results:Forty-three studies were included.The overall incidence rate was 5.70 injuries/1000 h in males and 6.77 injuries/1000 h in females.Match injury incidence(14.43 injuries/1000 h in males and 14.97 injuries/1000 h in females)was significantly higher than training injury incidence(2.77 injuries/1000 h in males and 2.62 injuries/1000 h in females).The lower extremity had the highest incidence rate in both sexes.The most common type of injury was muscle/tendon for males and joint/ligament for females.Minimal injuries were the most common in both sexes.The incidence rate of injuries increased with advances in chronological age in males.Elite male players presented higher match injury incidence than sub-elite players.In females,there was a paucity of data for comparison across age groups and levels of play.Conclusion:The high injury incidence rates and sex differences identified for the most common location and type of injury reinforce the need for implementing different targeted injury-risk mitigation strategies in male and female youth football players.

Mediation role of cardiorespiratory fitness on the association between fatness and cardiometabolic risk in European adolescents: The HELENA study

Purpose:This study was aimed to analyze the mediation role of cardiorespiratory fitness(CRF)on the association between fatness and cardiometabolic risk scores(CMRs)in European adolescents.Methods:A cross-sectional study was conducted in adolescents(n=525;46%boys;14.1±1.1 years old,mean ±SD)from 10 European cities involved in the Healthy Lifestyle in Europe by Nutrition in Adolescence study.CRF was measured by means of the shuttle run test,while fatness measures included body mass index(BMI),waist to height ratio,and fat mass index estimated from skinfold thicknesses.A clustered CMRs was computed by summing the standardized values of homeostasis model assessment,systolic blood pressure,triglycerides,total cholesterol/highdensity lipoprotein cholesterol ratio,and leptin.Results:Linear regression models indicated that CRF acted as an important and partial mediator in the association between fatness and CMRs in 1217-year-old adolescents(for BMI:coefficients of the indirect role b=0.058(95%confidence interval(95%CI):0.023-0.101),Sobel test z=3.11(10.0%mediation);for waist to height ratio:b=4.279(95%CI:2.242-7.059),z=3.86(11.5%mediation);and for fat mass index:b=0.060(95%CI:0.020-0.106),z=2.85(9.4%mediation);all p<0.01).Conclusion:In adolescents,the association between fatness and CMRs could be partially decreased with improvements to fitness levels;therefore,CRF contribution both in the clinical field and public health could be important to consider and promote in adolescents independently of their fatness levels.

Heart rate variability to assess ventilatory thresholds in professional basketball players

Purpose: The aim of this study was to determine if heart rate variability(HRV) during incremental test could be used to estimate ventilatory threshold(VT) in professional basketball players, with sufficient precision to be used in their training. Furthermore, the second aim was to analyse the association between HRV and 3 methods of VT determination by gas analysis.Methods: Twenty-four professional basketball players(age: 23.4 ± 4.9 years; height: 195.4 ± 9.8 cm; body mass: 92.2 ± 11.9 kg) performed an incremental running test to exhaustion. First ventilatory threshold(VT1) was determined by ventilatory equivalent(VE) and HRV and second ventilatory threshold(VT2) was determined by 3 methods of gases analysis(V-slope, VE and gas exchange ratio(R), and HRV). Pearson's coefficient(r) was used to detect differences between data and the strength of each relationship. The mean of absolute differences and Bland–Altman analysis were used to evaluate whether there was agreement.Results: The results showed no significant differences in HR and oxygen consumption(VO2) at VT1 between the 2 methods. Furthermore, no significant differences among the methods of gases analysis and HRV were observed in speed, HR, and VO2 at VT2. Moreover, VTs estimated using HRV and gas methods were significantly correlated. Correlation in HR values was higher between R and HRV(r = 0.96) and VE and HRV(r = 0.96) than V-slope and HRV(r = 0.90).Conclusion: These findings provide a practical, inexpensive approach for evaluating specific training loads when determining VT2 in basketball players. Therefore, HRV is an alternative method to determine VT2 without the application of expensive technology that limits its use to laboratories.