Test–retest reliability of physiological parameters in elite junior distance runners following allometric scaling

This study aimed to quantify the intra-individual reliability of a number of physiological variables in a group of national and international young distance runners. Sixteen (8 male, 8 female) participants (16.7?±?1.4 years) performed a submaximal incremental running assessment followed by a maximal running test, on two occasions separated by no more than seven days. Maximal oxygen uptake (V?O_2max), speed at V?O_2max (km?h^?1), running economy and speed and heart rate (HR) at fixed blood lactate concentrations were determined. V?O_2max and running economy were scaled for differences in body mass using a power exponent derived from a larger cohort of young runners (n?=?42). Running economy was expressed as oxygen cost and energy cost at the speed associated with lactate turnpoint (LTP) and the two speeds prior to LTP. Results of analysis of variance revealed an absence of systematic bias between trials. Reliability indices showed a high level of reproducibility across all parameters (typical error [TE] ≤2%; intra-class correlation coefficient >0.8; effect size <0.6). Expressing running economy as energy cost appears to provide superior reliability than using oxygen cost (TE ～1.5% vs. ～2%). Blood lactate and HR were liable to daily fluctuations of 0.14–0.22?mmol?L^?1 and 4–5?beats?min^?1 respectively. The minimum detectable change values (95% confidence) for each parameter are also reported. Exercise physiologists can be confident that measurement of important physiological determinants of distance running performance are highly reproducible in elite junior runners.     

健身类APP的SWOT分析——以KEEP为例

采用SWOT分析法,对当下健身类APP发展的优势、劣势、机遇和威胁因素进行分析并提出相关建议。研究认为健身类APP具有经济发展、便捷、科学化、互动性和个性化的优势,但存在项目内容单一、受设备配置影响较大以及盈利模式单一等方面的劣势;拥有健身人群不断扩大、政策机遇以及科普技术支撑这3大机遇,但面临来自竞争者、替代产品等方面的威胁。     

Associations between prolonged sedentary time and breaks in sedentary time with cardiometabolic risk in 10–14-year-old children: The HAPPY study

This study examines the association between prolonged sedentary time and breaks in sedentary time with cardiometabolic risk in 10–14-year-old children. This cross-sectional design study analysed accelerometry-determined sedentary behaviour and physical activity collected over 7 days from 111 (66 girls) UK schoolchildren. Objective outcome measures included waist circumference, fasting lipids, fasting glucose, blood pressure, and cardiorespiratory fitness. Logistic regression was used for the main data analysis. After adjustment for confounders, the odds of having hypertriglyceridaemia (P = 0.03) and an increased clustered cardiometabolic risk score (P = 0.05) were significantly higher in children who engaged in more prolonged sedentary bouts per day. The number of breaks in sedentary time per day was not associated with any cardiometabolic risk factor, but longer mean duration of daily breaks in sedentary time were associated with a lower odds of having abdominal adiposity (P = 0.04) and elevated diastolic blood pressure (P = 0.01). These associations may be mediated by engagement in light activity. This study provides evidence that avoiding periods of prolonged uninterrupted sedentary time may be important for reducing cardiometabolic disease risk in children.     

High-intensity interval training programme for obese youth (HIP4YOUTH): A pilot feasibility study

Recently, there has been growing interest in high-intensity interval training (HIT) as a strategy to improve health. In this pilot study, we examined the feasibility of a 4-week low-volume HIT and its effects on cardiorespiratory fitness (CRF), blood pressure (BP) and enjoyment in overweight and obese youth. Twelve adolescents (body mass index (BMI): 34.8 ± 3.9 kg · m^?2, 14.9 ± 1.5 years) participated in 12 sessions of HIT (10 × 60 s cycling bouts eliciting ~90% maximal heart rate, interspersed with 90 s recovery, 30 min/session, 3 sessions/week) over ~4 weeks. All the participants completed the study and exercise attendance averaged 92%. Despite no changes in body weight and total fat, HIT resulted in significant (P < 0.01) increases in CRF (pre: 20.1 versus post: 22.2 ml · kg^?1 · min^?1) and exercise time (pre: 425 versus post: 509 s) during peak oxygen uptake test, and a reduction in resting systolic BP (pre: 115.8 versus post: 107.6 mmHg). The majority of study participants (83%) enjoyed HIT and more than half of the participants (58%) reported that HIT is a more enjoyable form of exercise compared to other types of exercises. Low-volume HIT is a useful strategy to promote exercise participation and improve cardiovascular health in overweight and obese youth.     

The role of anthropometric,performance and psychological attributes in predicting selection into an elite development programme in older adolescent rugby league players

This study aimed to identify attributes that discriminate selected from non-selected players and predict selection into a rugby league development programme in older adolescent players. Anthropometric, performance and psychological attributes were measured in under-16 (N = 100) and under-18 (N = 60) rugby league players trialling for selection into a development programme with a professional Australian club. Sprint times (P < 0.001), predicted VO_2max (P = 0.002) and push-ups_1 min (P = 0.004) were superior in selected under-16 players, and sprint times (P ≤ 0.045), push-ups_1 min (P < 0.001) and chin-ups_1 min (P = 0.013) were superior in selected under-18 players. Further, 10-m sprint (β = ?7.706, standard error [SE] = 2.412), VO_2max (β = 0.168, SE = 0.052) and body mass (β = 0.071, SE = 0.023) significantly predicted selection (R² = 0.339) in under-16 players, while push-ups_1 min (β = 0.564, SE = 0.250), 10-m sprint (β = ?68.477, SE = 28.107), body mass (β = 0.360, SE = 0.155) and chronological age (β = ?3.577, SE = 1.720) significantly predicted selection (R² = 0.894) in under-18 players. These findings emphasise the importance of performance attributes in junior rugby league and indicate talent identification test batteries should be age-specific in older adolescent players.     

Match running performance and skill execution improves with age but not the number of disposals in young Australian footballers

This study investigated age-related differences in maturity, physical and functional characteristics and playing performance in youth Australian Football (AF). Young male players (n = 156) were recruited from 12 teams across 6 age groups (U10–U15) of a recreational AF club. All players were tested for body size, maturity and fitness. Player performance was assessed during a match in which disposals (kicks and handballs) and their effectiveness were coded from a video recording and match running performance measured using Global Positioning System. Significant main effects (P < 0.01) for age group were observed for age, years to peak height velocity, body mass, height, 20 m sprint, maximal speed over 20 m, vertical jump, 20 m multistage shuttle run, match distance, high-speed running distance, peak speed, number of effective disposals and percentage of effective disposals. Age-related differences in fitness characteristics (speed, lower body power and endurance) appeared to transfer to match running performance. The frequency in which players disposed of the football did not differ between age groups, however the effectiveness of each disposal (i.e., % effective disposals) improved with age. Match statistics, particularly those that evaluate skill execution outcome (i.e., effectiveness), are useful to assess performance and to track player development over time. Differences between age groups, and probably variability within age groups, are strongly associated with chronological age and maturity.     

国家一级篮球裁判员临场执裁体能现状分析

运用文献资料、问卷调查以及专家访谈等研究方法,分析现阶段国家一级篮球裁判员的临场执裁体能现状。结果表明:国家一级裁判员体能状况堪忧,缺少有计划性的体能训练、训练手段没有针对性,训练形式比较单一。为能使我国篮球裁判员在临场执裁时拥有充沛的体能,针对裁判员体能问题现状,提出改善裁判员体能水平的实施路径。     

学生体质健康测试区块链的平台架构、应用前景与现实挑战

党的十八大以来，学生体质健康测试被提到了新的高度，但当前的测试系统在数据存证、数据共享和监管追溯等方面均存在缺陷。习近平总书记将区块链列为新一代信息技术的代表，本文以学生体质健康测试区块链为研究对象，从平台架构、应用前景与现实挑战三个向度进行分析。研究发现：在“省级-地级-县级”的三级结构下，学生体质健康测试区块链可以优化测试结果的上传、录入和获取流程，从而实现数据的真实测量、个性分析和精准干预；学生体质健康测试区块链去中介化和去中心化的内在价值，使其在监测中心、政企合作和健康档案领域具有广阔的应用前景；学生体质健康测试区块链在理念、制度和技术上仍面临着较大挑战，但可以从矫正利害相关者的关注点、保障监测中心的自主权和引进高素质的技术人才三个方面来积极应对。     

体育运动与健康促进

为了探讨体育运动对大众健康的促进作用，采用文献资料、逻辑分析等研究方法，分析生活方式疾病对国民健康的影响以及体育运动在促进人类健康方面所起的作用。指出了体育健身是满足国民健康需求的重要途径，是21世纪我国健康促进的重要渠道。     

从我国青少年学生体质健康的现状透析开展阳光体育运动的意义

通过权威报告阐明了我国青少年学生体质健康的现状,然后全面分析了青少年学生体质下降的原因,在此基础上论述了开展亿万青少年学生阳光体育运动的重要意义。