Objective and subjective methods for quantifying training load in wheelchair basketball small-sided games

The aim of the present study was to analyse the training load in wheelchair basketball small-sided games and determine the relationship between heart rate (HR)-based training load and perceived exertion (RPE)-based training load methods among small-sided games bouts. HR-based measurements of training load included Edwards’ training load and Stagno’s training impulses (TRIMP_MOD) while RPE-based training load measurements included cardiopulmonary (session RPEres) and muscular (session RPEmus) values. Data were collected from 12 wheelchair basketball players during five consecutive weeks. The total load for the small-sided games sessions was 67.5 ± 6.7 and 55.3 ± 12.5 AU in HR-based training load (Edwards’ training load and TRIMP_MOD), while the RPE-based training loads were 99.3 ± 26.9 (session RPEres) and 100.8 ± 31.2 AU (session RPEmus). Bout-to-bout analysis identified greater session RPEmus in the third [P < 0.05; effect size (ES) = 0.66, moderate] and fourth bouts (P < 0.05; ES = 0.64, moderate) than in the first bout, but other measures did not differ. Mean correlations indicated a trivial and small relationship among HR-based and RPE-based training loads. It is suggested that HR-based and RPE-based training loads provide different information, but these two methods could be complementary because one method could help us to understand the limitations of the other.     

Effects of heat acclimation on hand cooling efficacy following exercise in the heat

This study examined the separate and combined effects of heat acclimation and hand cooling on post-exercise cooling rates following bouts of exercise in the heat. Seventeen non-heat acclimated (NHA) males (mean ± SE; age, 23 ± 1 y; mass, 75.30 ± 2.27 kg; maximal oxygen consumption [VO₂ max], 54.1 ± 1.3 ml·kg^?1·min^?1) completed 2 heat stress tests (HST) when NHA, then 10 days of heat acclimation, then 2 HST once heat acclimated (HA) in an environmental chamber (40°C; 40%RH). HSTs were 2 60-min bouts of treadmill exercise (45% VO₂ max; 2% grade) each followed by 10 min of hand cooling (C) or no cooling (NC). Heat acclimation sessions were 90–240 min of treadmill or stationary bike exercise (60–80% VO₂ max). Repeated measures ANOVA with Fishers LSD post hoc (α < 0.05) identified differences. When NHA, C (0.020 ± 0.003°C·min^?1) had a greater cooling rate than NC (0.013 ± 0.003°C·min^?1) (mean difference [95%CI]; 0.007°C [0.001,0.013], P = 0.035). Once HA, C (0.021 ± 0.002°C·min^?1) was similar to NC (0.025 ± 0.002°C·min^?1) (0.004°C [?0.003,0.011], P = 0.216). Hand cooling when HA (0.021 ± 0.002°C·min^?1) was similar to when NHA (0.020 ± 0.003°C·min^?1) (P = 0.77). In conclusion, when NHA, C provided greater cooling rates than NC. Once HA, C and NC provided similar cooling rates.     

Effect of a Brazilian Jiu-jitsu-simulated tournament on strength parameters and perceptual responses

This study aimed to analyse the effects of a simulated Brazilian jiu-jitsu (BJJ) tournament on vertical jump performance, grip strength test and perceived effort responses. 22 male BJJ athletes participated in a simulated tournament consisting of three 7 min matches separated by 14 min of rest. Kimono grip strength test (KGST), counter movement jump (CMJ) and rate of perceived exertion (RPE) were measured before and after each match, while RPE of specific areas was assessed after three matches. ANOVA for repeated measures was used to compare strength parameters after each match with the level of significance set at 5%. The key results showed a significant decrease of jump height (p = 0.001) and net vertical impulse in the CMJ (p = 0.031), as well as a reduction of the number of reps in the KGST (p < 0.001). A significant increase of RPE was found throughout the matches (p < 0.001). Considering the RPE in specific areas, no differences were observed between the upper and lower body (p = 0.743). We conclude that the BJJ simulated tournament generated a decrease of performance in both upper and lower limbs and provoked a progressive increase in the effort perception over the matches.     

Maximal heart rate declines linearly with age independent of cardiorespiratory fitness levels

There have been many conflicting observations between the linear or curvilinear decline in maximal heart rate (HR_max) with age. The aim of this study was to determine if linear or curvilinear equations would better describe the decline in HR_max with age in individuals of differing cardiorespiratory fitness (CRF) levels. Treadmill cardiopulmonary exercise test (CPX) results from participants (1510 men and 1134 women; 18–76 years) free of overt cardiovascular disease were retrospectively examined using cross-sectional and longitudinal study designs. Participants completing ≥2 CPX with ≥1 year between test dates were included in the longitudinal analysis (325 men and 150 women). Linear and quadratic regressions were applied to age and HR_max for the whole cohort and respective CRF groups (high, moderate, and low, relative to age and gender normative values). To test for differences among linear, quadratic, and polynomial equations, the change in R² (cross-sectional analysis) and Bayesian information criterion (BIC) (longitudinal analysis) from the linear to the more complex models were calculated. The quadratic or polynomial regression in the cross-sectional analysis, marginally improved the variance in HR_max explained by age compared to the linear regression for the whole cohort (0.2%), moderate fit group (0.3%), and low fit group (0.8%). With no improvements in the high fit group. BIC did not improve for any CRF category in the longitudinal analysis. In conclusion, the minimal differences among linear, quadratic, and polynomial equations in the respective CRF groups, emphasizes the use of linear prediction equations to estimate HR_max.     

房产税改革的方案选择及财税效应分析

对房产持有环节开征房产税具有国际通用的合理性和合法性,房产税改革是新一轮国家财税体制改革的重要内容。对国内主要城市的房产税改革方案及其财税效应分析表明：采用无差别税率征税方案的优势在于减少征管成本、确保居民纳税义务的公平性,劣势在于造成纳税人税负过重、不利于调节财富分配差距;而按住房面积采用递进税率征税方案的优势在于能够调节贫富差距、体现“量能负担”原则,劣势在于容易被纳税人投机取巧而逃避高税率和监管。权衡利弊,“每人享受一定面积的减免,根据住房面积大小、基于公告价值或评估价值按不同税率征收”的方案,可作为今后房产税改革的主要方向。     

高强度运动对心脏的冲击影响及信号提取研究

设计实时的肌肉组织血氧量和瞬时心率无损同步检测方案与设备,为研究高强度运动心脏的冲击影响、探讨高强度运动中代谢规律提供测试手段。方法:采用连续双波长近红外光测量肌肉中血红蛋白与肌红蛋白含氧量的变化情况;采用芬兰SUUNTO心率带和自行设计的转发器及配套PC软件测量瞬时心率,进行了100m跑同步实测试验。结果:100m跑以无氧代谢为主。起跑后的前7s为无氧代谢的非乳酸功能,肌氧饱和度曲线变化不大。7s后开始消耗肌肉中储存的氧。结论:双波长近红外光组织氧测试法和运动心率无线实时采集系统能够正确实时同步地检测高强度运动时血氧和心率,揭示了高强度运动过程中肌肉中氧的运输与消耗及心率之间的动力学过程。     

久期技术与基于隐含期权的商业银行利率风险管理

从衡量利率风险的久期与凸度技术出发,重点探讨了基于隐含期权及期权调整利差的有效久期和有效凸度模型,并研究了其在我国商业银行利率风险管理中的具体应用。     

Visual function,performance, and processing of basketball players vs. sedentary individuals

BackgroundAthletes tend to have better visuo-motor performance than do sedentary individuals. However, several basic visual-function and perceptual parameters remain unexplored to date. In this study, we investigated whether differences exist in visual function, performance, and processing between basketball players and individuals without a sport-involvement background.MethodsA total of 33 healthy men with no visual impairment or pathology were divided into 2 groups, depending on the involvement in sport (semi-professional basketball players and sedentary individuals). We tested their baseline heart-rate variability in the resting position apart from subjective questionnaires to determine their physical fitness level, and we checked their visual function, performance, and processing through an extended battery of optometric tests.ResultsThe 2 groups differed in resting heart-rate variability parameters (p < 0.001), confirming their dissimilarities in regular time practising sports per week. The basketball players showed a closer breakpoint and recovery nearpoint of convergence, a higher fusional-vergence rate, better discriminability halos, and better eye–hand coordination (all p values < 0.05).ConclusionThese results show evidence that athletes, basketball players in this case, exhibit better performance in several visual abilities in comparison to a group of individuals without sporting backgrounds, suggesting an improvement due to the systematic involvement of those skills during basketball practice.     

体育用品企业如何应对人民币升值的冲击

在分析我国体育用品市场现状的基础上，研究了人民币汇率变动的趋势以及汇率的变动对体育用品企业的影响，探讨了面临人民币升值的压力，如何趋利避害，合理利用国外生产要素，降低生产成本．及时归还和调整外汇债务，借鉴外国经验，大力推进对外直接投资。     

省青少年比赛中篮球裁判员运动强度影响因素的研究

探讨比赛中篮球裁判员心率与年龄和体重等指标的关系;进一步比较不同级别篮球裁判员在比赛中生理指标的变化特征。对不同级别裁判员的赛中心率变化分析表明：在省青少年篮球比赛中,裁判级别对心率分布、最高心率和平均心率等指标无明显影响。相关分析表明篮球裁判员在省青少年比赛中的心率指标与年龄、体重以及级别之间无相关关系。