nal procedure goes smoothly, so it

it may violate human beings’ rights when exerted improperly. Paying sufficient attention to the essence and objective of pre-trial detention c     

Restricting opportunities to be active during school time: do children compensate by increasing physical activity levels after school?

Opportunities for children to be physically active during school time are sparse and becoming increasingly so. The purpose of this investigation was to determine if children would compensate for school days (9 a.m.-3 p.m.) of restricted physical activity opportunities by increasing activity levels after school (3 p.m.-7:30 p.m.). Third and fourth grade children (N = 76) each wore a CSA accelerometer for 4 nonconsecutive days. Two days were categorized as active--during school, all children participated in outdoor recess and physical education class. Two days were categorized as restricted--all children spent their recess time indoors at a computer terminal, and no physical education class was scheduled. Dependent t tests revealed that children did not compensate for a sedentary school day by increasing their levels of physical activity after school. In fact, average movement counts per minute were higher in the 3 p.m.-7:30 p.m. period following the active day (525 counts.min-1) versus the restricted day (186 counts.min-1). These findings suggest cause for concern if children's opportunities to be active within school time are limited. Several reasons are given as to why children did not compensate or "make up" for the physical activity opportunities missed during the restricted school day.     

Influence of football match time–motion parameters on recovery time course of muscle damage and jump ability

ABSTRACT

We analysed the time course of recovery of creatine kinase (CK) and countermovement jump (CMJ) parameters after a football match, and correlations between changes in these variables and match time–motion parameters (GPS-accelerometry) in 15 U-19 elite male players. Plasma CK and CMJ height (CMJ_H), average concentric force (CMJ_CON) and average eccentric force (CMJ_ECC) were assessed 2 h before and 30 min, 24 h and 48 h post-match. There were substantially higher CK levels 30 min, 24 h and 48 h (ES: 0.43, 0.62, 0.40, respectively), post-match. CMJ_ECC (ES: ?0.38), CMJ_H (ES: ?0.35) decreased 30 min post, CMJ_CON (ES: ?0.35), CMJ_ECC (ES: ?0.35) and CMJ_H (ES: ?1.35) decreased 24 h post, and CMJ_CON (ES: ?0.41) and CMJ_H (ES: ?0.53) decreased 48 h post. We found correlations between distance covered at velocities ≤21 km · h^?1 and changes in CK at 24 h (r = 0.56) and at 48 h (r = 0.54) and correlations between CK and distance covered >14 km · h^?1 (r = 0.50), accelerations (r = 0.48), and decelerations (r = 0.58) at 48 h. Changes in CMJ_CON 30 min and 24 h post (both r = ?0.68) correlated with impacts >7.1·G. Decelerations >2 m · s^?2 correlated with changes CMJ_CON (r = ?0.49) at 48 h and CMJ_ECC (r = ?0.47) at 30 min. Our results suggest that match GPS-accelerometry parameters may predict muscle damage and changes in components of neuromuscular performance immediately and 24–48 h post-match.     

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.     

The force–time profile of elite front crawl swimmers

Abstract

In this study, we used recently developed technology to determine the force–time profile of elite swimmers, which enabled coaches to make informed decisions on technique modifications. Eight elite male swimmers with a FINA (Federation Internationale de Natation) rank of 900+ completed five passive (streamline tow) and five net force (arms and leg swimming) trials. Three 50-Hz cameras were used to video each trial and were synchronized to the kinetic data output from a force-platform, upon which a motorized towing device was mounted. Passive and net force trials were completed at the participant's maximal front crawl swimming velocity. For the constant tow velocity, the net force profile was presented as a force–time graph, and the limitation of a constant velocity assumption was acknowledged. This allowed minimum and maximum net forces and arm symmetry to be identified. At a mean velocity of 1.92 ± 0.06 m · s^?1, the mean passive drag for the swimmers was 80.3 ± 4.0 N, and the mean net force was 262.4 ± 33.4 N. The mean location in the stroke cycle for minimum and maximum net force production was at 45% (insweep phase) and 75% (upsweep phase) of the stroke, respectively. This force–time profile also identified any stroke asymmetry.     

Key determinants of time to 5 m in different ventral swimming start techniques

The aim of this study was to determine the biomechanical parameters that explain ventral start performance in swimming. For this purpose, 13 elite swimmers performed different variants of the ventral start technique. Two-dimensional video analyses of the aerial and underwater phases were used to assess 16 kinematic parameters from the starting signal to 5?m, and an instrumented starting block was used to assess kinetic data. A Lasso regression was used to reduce the number of parameters, providing the main determinants to starting performance, revealing different combinations of key determinants, depending on the variant (r²?≥?0.90), with flight distance being the most relevant to all variants (r?≤??0.80; p?r?=??0.79; p?r?≤?0.61; p?r²?=?0.66) or block time and flight distance (r²?=?0.83). These data provide relevant contributions to the further understanding of the biomechanics of swimming starts as well as insights for performance analysis and targeted interventions to improve athlete performance.     

The effect of β-alanine supplementation on cycling time trials of different length

The varying results reported in response to β-alanine supplementation may be related to the duration and nature of the exercise protocol employed. We investigated the effects of β-alanine supplementation on a wide range of cycling performance tests in order to produce a clear concise set of criteria for its efficacy. Fourteen trained cyclists (Age?=?24.8?±?6.7?years; VO_2max?=?65.4?±?10.2 mL·kg·min^?1) participated in this placebo-controlled, double-blind study. Prior to supplementation, subjects completed two (familiarization and baseline) supramaximal cycling bouts until exhaustion (120% pre-supplementation VO_2max) and two 1-, 4- and 10-km cycling time trial (TT). Subjects then supplemented orally for 4 weeks with 6.4?g/d placebo or β-alanine and repeated the battery of performance tests. Blood lactate was measured pre-exercise, post-exercise and 5 min post-exercise. β-alanine supplementation elicited significant increases in time to exhaustion (TTE) (17.6?±?11.5 s; p?=?0.013, effect compared with placebo) and was likely to be beneficial to 4-km TT performance time (?7.8?±?8.1 s; 94% likelihood), despite not being statistically different (p?=?0.060). Performance times in the 1- and 10-km TT were not affected by treatment. For the highly trained cyclists in the current study, β-alanine supplementation significantly extended supramaximal cycling TTE and may have provided a worthwhile improvement to 4-km TT performance. However, 1- and 10-km cycling TT performance appears to be unaffected by β-alanine supplementation.     

Hell it s about time——星际Ⅱ歪批第二弹

2007年9月刊《星际Ⅱ歪批第一弹》为大家送上了许多"异想天开"的理念,许多读者也对此表示了极大的兴趣。距离上次Blizzoon的Re-Aplah版,如今已经过了8个月了。在这期间,暴雪也不定期地为大家放出官方的FAQ。万众期待的Zerg虫族也终于在3月10日这天大举入侵地球。中、美、韩三地玩家都先后领略到了新生Zerg的恐怖之处。同时我们也看到了更多更详细的有关星际Ⅱ的资料,这让全世界玩家都兴奋得很。小编自然也坐不住了,我们这个对星际Ⅱ评头论足的栏目也应该继续了,这里仍然会不定期地出现最新的星际Ⅱ消息、评论和不负责任的猜想。Hell,it's about time!     

Effects of breaking up sedentary time with “chair squats” on postprandial metabolism

Prolonged sitting induces adverse metabolic changes. We aimed to determine whether breaking up prolonged sedentary time with short periods of repeated sit-to-stand transitions (“chair squats”) every 20 minutes influences postprandial metabolic responses. Fourteen participants (11 men, 3 women), age 37 ± 16 years, BMI 30.5 ± 3.8 kg.m^?2 (mean ± SD) each participated in two experimental trials in random order, in which they arrived fasted, then consumed a test breakfast (8 kcal.kg^?1 body weight, 37% energy from fat, 49% carbohydrates, 14% protein) and, 3.5 hours later, an identical test lunch. Expired air and blood samples were taken fasted and for 6.5 hours postprandially. In one trial (SIT) participants sat continuously throughout the observation period; in the “Chair squat” trial (SIT/STAND), participants performed “chair squats” (10 × standing and sitting over 30 seconds, every 20 minutes). Compared to SIT, energy expenditure was 409.7 ± 41.6 kJ (16.6 ± 1.7%) higher in SIT/STAND (p < 0.0001). Postprandial insulin concentrations over the post-breakfast period were 10.9 ± 8.4% lower in SIT/STAND than SIT (p = 0.047), but did not differ between trials in the post-lunch period. Glucose and triglyceride concentrations did not differ significantly between trials. These data demonstrate that a simple, unobtrusive intervention to break up sedentary time can induce some favourable metabolic changes.     

Is physical performance(in mice)increased by Veillonella atypica or decreased by Lactobacillus bulgaricus?

1.Introduction Regular exercise induces changes in the overall diversity and in the relative abundance of certain gut microbiota phyla and families in humans1,2 and in animal models.3,4 This relationship has attracted a great deal of interest because it is one of the mechanisms involved in the health benefits of regular exercise3 that could also influence performance.5 A recent publication by Scheiman et al.     

行走的地中海 Finca luisa by Longchamp

福柯曾经提出过一个非常令人振奋的观点:从什么时候开始,艺术成了一个专门的行当?难道只有画家画画,音乐家作曲,雕塑家雕刻,文学家写作,才是艺术活动?为什么人的生活不应当成为一件精美的艺术品?没错,审美并不只属于艺术家,每个人都应该拥有自己的艺术,而时尚的本质就是将艺术融入世俗,让生活成为一种审美。     

Does installation of the backstroke start device reduce 15-m start time in swimming?

The purpose of this study was to determine the installation of the backstroke start device reduces 15-m time. Thirteen college swimmers participated in this study. The aerial start and underwater motions were recorded with two digital video cameras. The center of mass (CM) of the swimmer, angular displacements and velocities of the shoulder, hip and knee joints were calculated. As an indicator of performance, the 5- and 15-m times were measured. The 5- and 15-m times in the backstroke start device condition were significantly shorter than in the non-backstroke start device condition. The vertical velocities of the CM at hand-off and toe-off in the backstroke start device condition were significantly greater than in the non-backstroke start device condition, while there was no significant difference in the CM horizontal velocity at toe-off. As a result, the height of the great trochanter at entry of the fingertips, with the backstroke start device, was 15 cm higher than in the non-backstroke start device condition. In addition, the CM horizontal velocities at 5 m in the backstroke start device condition were significantly greater than those of the non-backstroke start device. Thus, the use of the backstroke start device may reduce the 15-m time by diminution of the entry area.     

The Second Conference by ‘China 2009’

Organizing Committee of China 2009 World Philatelic Exhibition (‘China 2009’) held the second conference at the Ministry of Communications, December 25, 2008. At the meeting, new committee Director approved by the State Council     

Acute effects of exercise and active video games on adults’ reaction time and perceived exertion

The purpose of the present study was to examine the acute effects of resting, aerobic exercise practised alone, and aerobic exercise with active video games (AVG), on complex reaction time (CRT) and the post-exercise acute rate of perceived exertion (RPE) in young healthy adults. The experimental group was composed of 92 healthy young adults, 78 males and 13 females (age M?=?21.9?±?2.7 years) who completed two sessions, A and B. In session A, participants rode 30?min on an ergometer, while in session B they exercised for 30?min on an ergometer while playing an AVG on a Wii. The control group was composed of 30 young adults, 26 males and 4 females (age M?=?21.4?±?2.9 years) who rested for 30?min. In each session, a CRT task was performed before and after exercising or resting, and post-exercise global RPE was noted. Repeated measures general linear model (GLM) and Wilcoxon tests were performed. (1) Both aerobic exercise alone and aerobic exercise combined with AVG improved CRT, while resting did not; (2) aerobic exercise combined with AVG did not improve CRT more than aerobic exercise only; and (3) RPE was lower after aerobic exercise combined with AVG compared with aerobic exercise only. In young adults, exercise produces acute benefits on CRT, and practising exercise with AVG helps to decrease RPE.     

Does light-intensity physical activity moderate the relationship between sitting time and adiposity markers in adolescents?

Background:While the relationship between sedentary time and adiposity markers may be independent of moderate-to-vigorous intensity physical activity(MVPA) among adolescents,little is known about the role of light-intensity physical activity(LIPA) in this relationship.The aim of this cross-sectional study was to examine whether device-measured LIPA and MVPA moderate the associations between objectively measured sitting time and adiposity markers(body mass index(BMI)) and waist circumference(WC))...     

A mathematical modelling study of an athlete’s sprint time when towing a weighted sled

This study used a mathematical model to examine the effects of the sled, the running surface, and the athlete on sprint time when towing a weighted sled. Simulations showed that ratio scaling is an appropriate method of normalising the weight of the sled for athletes of different body size. The relationship between sprint time and the weight of the sled was almost linear, as long as the sled was not excessively heavy. The athlete’s sprint time and rate of increase in sprint time were greater on running surfaces with a greater coefficient of friction, and on any given running surface an athlete with a greater power-to-weight ratio had a lower rate of increase in sprint time. The angle of the tow cord did not have a substantial effect on an athlete’s sprint time. This greater understanding should help coaches set the training intensity experienced by an athlete when performing a sled-towing exercise.