Influence of gender on ventilatory efficiency during exercise in young children

In this study, we assessed the ventilatory response in 84 children (46 males: age 8.1 +/- 1.0 years, body mass 34.2 +/- 7.9 kg, height 1.32 +/- 0.16 m; 38 females: age 8.0 +/- 0.8 years, body mass 31.7 +/- 8.7 kg, height 1.31 +/- 0.08 m) during a cycle ergometer test to determine if there was an influence of gender on ventilatory efficiency. The test commenced at 25 W and increased by 10 W every minute. Expired air was collected through a face mask and analysed breath by breath. The ventilatory anaerobic threshold was determined according to gas exchange methods and we focused our attention on the analysis of carbon dioxide production (VCO(2)), ventilation (V(E)), the ratio V(E)/VCO(2) and its slope. Differences between the sexes at maximal power output were strongly significant for V(E) and VCO(2) (P = 0.0001 and P = 0.0004 respectively) and moderately significant for the V(E)/VCO(2) ratio (P = 0.05). The slope of V(E) versus VCO(2) was 30.8 +/- 4.2 for males and 29.4 +/- 3.2 for females, with no difference between the sexes (P = 0.1). In conclusion, although the peak values of V(E) and VCO(2) were significantly different between the sexes, there were no such differences in ventilatory efficiency during a maximal incremental test expressed as the slope of V(E)/VCO(2), at least in young children.     

体育锻炼对儿童性别角色社会化的影响

采用玩具选择任务研究范式,对81名来自小学和业余体校的儿童进行了实验研究。结果表明:(1)儿童性别角色的社会化受到儿童的性别、体育运动项目以及参加该运动时间等因素的影响。(2)参加跆拳道和体操训练都会强化男孩的男性化性别角色,弱化女孩的女性化性别角色。参加跆拳道训练对儿童性别角色的影响较参加体操训练更明显。(3)参加体育运动的时间越长,对儿童性别角色社会化的影响越大。     

Sex differences in wheelchair propulsion biomechanics and mechanical efficiency in novice young able-bodied adults

An awareness of sex differences in gait can be beneficial for detecting the early stages of gait abnormalities that may lead to pathology. The same may be true for wheelchair propulsion. The aim of this study was to determine the effect of sex on wheelchair biomechanics and mechanical efficiency in novice young able-bodied wheelchair propulsion. Thirty men and 30 women received 12 min of familiarisation training. Subsequently, they performed two 10-m propulsion tests to evaluate comfortable speed (CS). Additionally, they performed a 4-min submaximal propulsion test on a treadmill at CS, 125% and 145% of CS. Propulsion kinetics (via Smart^wheel) and oxygen uptake were continuously measured in all tests and were used to determine gross mechanical efficiency (GE), net efficiency (NE) and fraction of effective force (FEF). Ratings of perceived exertion (RPE) were assessed directly after each trial. Results indicated that CS for men was faster (0.98?±?0.24?m/s) compared to women (0.71?±?0.18?m/s). A lower GE was found in women compared to men. Push percentage, push angle and local RPE were different across the three speeds and between men and women. NE and FEF were not different between groups. Thus, even though their CS was lower, women demonstrated a higher locally perceived exertion than men. The results suggest sex differences in propulsion characteristics and GE. These insights may aid in optimising wheelchair propulsion through proper training and advice to prevent injuries and improve performance. This is relevant in stimulating an active lifestyle for those with a disability.     

智障成年人运动效能评定量表的编制

根据运动效能的操作定义,结合智障成年人身心特点,在访谈和调研的基础上编制智障成年人运动效能评定量表。对量表进行内容效度、结构效度和信度检验的结果表明:结构模型确定运动效能量表的维度包括基本体育运动能力、体育运动中的心理过程和体育运动中的适应行为。验证性分析检验拟合优度和调整拟合优度较高,评价结果的相关矩阵与理论模型之间拟合较好,可以接受理论模型的结构。量表的11个指标的重测信度比较高,说明该量表具有一定的稳定性,可用于智障成年人运动效能的评定。     

锻炼行为和锻炼动机的性别差异——以高知人员为例的比较研究

对590名高级知识分子作问卷调查,对比分析了两性的健康状况、体育行为和锻炼动机。结果表明：①与男性相比,女性高知人员每次锻炼的时间短,锻炼强度小,两性体育锻炼频率和锻炼坚持差异不显著;②女性高知人员的外貌动机和乐趣动机明显强于男性,是她们参与体育锻炼的主要心理动力,这样的锻炼动机模式使她们选择参与轻松、对抗小和娱乐性强的体育锻炼项目;③高知人员健康状况不存在显著性性别差异,锻炼行为和动机存在的差异符合女性的身心特点,反映出在高知人员中性别平等程度较高。     

Effect of asthma and six-months high-intensity interval training on heart rate variability during exercise in adolescents

ABSTRACT

Little is known regarding the influence of asthma and exercise, and their interaction, on heart rate variability (HRV) in adolescents.

Thirty-one adolescents with asthma (13.7±0.9 years; 21.9±3.9 kg·m^?2; 19 boys, 12 girls) and thirty-three healthy adolescents (13.8±0.9 years; 20.3±3.2 kg·m^?2; 16 boys, 17 girls) completed an incremental ramp test and three heavy-intensity constant-work-rate cycle tests. Thirteen adolescents (7 boys, 6 girls; 6 asthma, 7 control) completed six-months high-intensity interval training (HIIT) and were compared to age- and sex-matched controls. Standard time-domain, frequency-domain and non-linear indices of HRV were derived at baseline, three- and six-months.

Asthma did not influence HRV at baseline or following HIIT. Total power, low frequency and normalised low frequency power, and sympathovagal balance increased at three-months in HIIT, subsequently declining towards baseline at six-months. Normalised high frequency power was reduced at three-months in both groups, which was sustained at six-months. No effects of HIIT were observed in the time-domain nor in the non-linear indices.

HRV was not influenced by asthma, potentially because such derangements are a function of disease progression, severity or duration. HIIT may be associated with a short-term shift towards greater sympathetic predominance during exercise, perhaps caused by physiological overload and fatigue.     

Muscle oxygenation and EMG activity during isometric exercise in children

Abstract

The aim of this study was to examine the time-course of and the relationships between muscle oxygenation, blood volume and myoelectrical manifestations during isometric exercise in children. Twelve healthy children aged 12.5 ± 1.2 years (mean ± s) performed an isometric knee extension at 50% of their maximal voluntary contraction (MVC) until exhaustion to assess endurance time (limit time, T _lim). Changes in muscle oxygenation and blood volume were assessed by near infrared spectroscopy (NIRS). The root mean square (RMS) amplitude and the mean power frequency (MPF) from electromyogram (EMG) signals were obtained, as NIRS parameters, from the vastus lateralis. Mean T _lim was 117 ± 34 s. The muscle oxygenation and blood volume curves decreased immediately at the beginning of exercise. Maximal deoxygenation occurred at 50% T _lim, and fell by 76.9% from the resting value. Similarly, minimal blood volume was observed at 50% T _lim; it reached a plateau that lasted until the end of exercise. The kinetics of the MPF and RMS curves were inversely related to time. At the last set of exercises (after 75% T _lim), a steeper RMS curve and an abrupt decrease in the MPF curve were observed. Significant correlations (r) between muscle oxygenation, blood volume, root mean square amplitude and mean power frequency were observed, which ranged from 0.72 to 0.99. These findings suggest that the fatigue resulting from sustained isometric exercise is related to a decrease in oxygenation and blood volume.     

Influence of moderate intensity physical activity levels and gender on conditioned pain modulation

This study examined the potential influence of moderate intensity physical activity (PA) levels and gender on central pain modulation using conditioned pain modulation (CPM) in healthy men and women. Twenty four individuals (12 men and 12 women) who reported engaging in the moderate intensity PA for 150 min or more per week and 24 individuals (12 men and 12 women) who reported engaging in moderate intensity PA for 60 min or less per week completed a self-report PA questionnaire and a 7-day PA assessment using an accelerometer. Furthermore, the participants completed the CPM testing to evaluate the efficiency of central pain modulation. The active individuals scored higher on the PA questionnaire and spent more minutes for light, lifestyle, moderate and vigorous intensity PA than the less active individuals. The active men and women exhibited comparable magnitudes of CPM, and showed a greater magnitude of CPM when compared to their less active counterparts. However, these beneficial effects of higher dose moderate intensity PA disappeared when time spent for vigorous intensity PA was statistically controlled for. These results suggest that the higher dose moderate intensity PA does not add to the benefits from vigorous intensity PA to further improve central pain modulatory systems.     

Feeling states during exercise: Influence of individual differences in perceived evaluative threat

Abstract

The present study is designed to examine the influence of individual differences in perceived evaluative threat and baseline responses on changes in feeling states experienced during acute exercise in college-age women with high social physique anxiety. Thirty women with high social physique anxiety completed acute bouts of stationary cycling at either a self-selected or imposed intensity in both naturalistic fitness centre and laboratory environments. Multivariate analysis of changes in feeling states during exercise yielded a significant baseline×perceived evaluative threat×intensity interaction during exercise in the naturalistic fitness centre environment. Decomposition of this interaction revealed that, within the naturalistic environment, women with the least favourable baseline feeling states who perceived the lowest amount of evaluative threat during exercise demonstrated the greatest improvements in affect during self-selected intensity exercise. These findings suggest that, among women with high social physique anxiety, changes in feeling states reported during exercise are influenced by an interaction between baseline affective responses, the intensity of exercise, and environmentally induced perceptions of evaluative threat.     

普通高校青年知识分子体育锻炼现状调查及对策研究

采用问卷调查、数理统计等方法，对我国普通高校部分青年知识分子体育锻炼现状进行了调查与研宄。结果显示，青年知识分子体育人口数量少(37．41％)；锻炼项目以散步、跑步、篮足排球为主；锻炼动机以健身、陪子女运动和消遣娱乐为主；锻炼场所以本校体育场馆、住家附近的空地为主；体育消费水平偏低；影响其参加体育锻炼的主要因素是工作紧、家务忙、无经费。针对存在的问题，提出了相应对策和建议。     

儿童体育道德发展过程中的性别差异

采用较好信度和效度的量表对小学三年级、五年级和初中二年级6个班的300学生（其中男161人，女139人），进行测量，其目的是探明体育道德发展过程中是否存在性别差异，以便在体育教学中对男女学生采用不同道德教育手段和方法，结果表明道德判断和道德行为得分存在着性别差异。     

The influence of drink temperature on thermoregulatory responses during prolonged exercise in a moderate environment

Abstract

Nine males cycled at 53% (s = 2) of their peak oxygen uptake ([Vdot]O_2peak) for 90 min (dry bulb temperature: 25.4°C, s = 0.2; relative humidity: 61%, s = 3). One litre of flavoured water at 10 (cold), 37 (warm) or 50°C (hot) was ingested 30 – 40 min into exercise. Immediately after the 90 min of exercise, participants cycled at 95%[Vdot]O_2peak to exhaustion to assess exercise capacity. Rectal and mean skin temperatures and heart rate were recorded. The gradient of rise in rectal temperature was influenced (P < 0.01) by drink temperature. Mean skin temperature was highest in the hot trial (cold trial: 34.2°C, s = 0.5; warm trial: 34.4°C, s = 0.5; hot trial: 34.7°C, s = 0.6; P < 0.01). Significant differences were observed in heart rate (cold trial: 132 beats · min^?1, s = 13; warm trial: 134 beats · min^?1, s = 12; hot trial: 139 beats · min^?1, s = 13; P < 0.05). Exercise capacity was similar between trials (cold trial: 234 s, s = 69; warm trial: 214 s, s = 52; hot trial: 203 s, s = 53; P = 0.562). The heat load and debt induced via drinking resulted in appropriate thermoregulatory reflexes during exercise leading to an observed heat content difference of only 33 kJ instead of the predicted 167 kJ between the cold and hot trials. These results suggest that there may be a role for drink temperature in influencing thermoregulation during exercise.     

The effect of short-duration sprint interval exercise on plasma postprandial triacylglycerol levels in young men

Abstract

It is well established that regular exercise can reduce the risk of cardiovascular disease, although the most time-efficient exercise protocol to confer benefits has yet to be established. The aim of the current study was to determine the effects of short-duration sprint interval exercise on postprandial triacylglycerol. Fifteen healthy male participants completed two 2 day trials. On day 1, participants rested (control) or carried out twenty 6 s sprints, interspersed with 24 s recovery (sprint interval exercise – 14 min for total exercise session). On day 2, participants consumed a high-fat meal for breakfast with blood samples collected at baseline, 2 h and 4 h. Gas exchange was also measured at these time points. On day 2 of control and sprint interval exercise trials, there were no differences (P < 0.05) between trials in plasma glucose, triacylglycerol, insulin or respiratory exchange ratio (RER). The area under the curve for plasma triacylglycerol was 7.67 ± 2.37 mmol · l^–1.4 h^–1 in the control trial and 7.26 ± 2.49 mmol · l^–1.4 h^–1 in the sprint interval exercise trial. Although the sprint exercise protocol employed had no significant effect on postprandial triacylglycerol, there was a clear variability in responses that warrants further investigation.     

膳食脂肪对运动能力的影响及运动时脂代谢的调节

就膳食脂肪对运动能力的影响以及脂肪代谢的调节作一综述。运动强度、时间不同，脂肪供能所占的比例不同，脂肪供能对运动成绩的影响也有所差异。运动时脂代谢的调节受多种因素的影响，激素敏感性甘油三酯脂肪酶(HSL)是酶解速度的主要控制因素。     

健身处方锻炼对中小学生攻击性行为影响的研究

利用修订的Olweus攻击性行为问卷对9205名城乡中小学生进行了测试,考察中小学生攻击性行为的基本状况。针对中小学生的攻击性行为,采用不同的健身运动处方锻炼来进行矫正。研究结果表明:中小学生中存在着较严重的攻击性行为问题,总体上中小学生攻击性行为的发生率随年级的升高而下降,但攻击性行为在初中阶段具有稳定性;直接言语攻击是最为普遍的攻击方式;攻击性行为的比率及攻击类型上均存在性别差异;健身运动处方锻炼能矫正中小学生攻击性行为,有利于培养他们的良好心理状态,促进他们身心健康。根据实验结果得出一些结论,并提出一些建议。     

肢体运动对学龄儿童EEG影响的实验研究

以小学4年级学龄儿童为研究对象,以同步反应脑电活动的脑电图(EEG)为主要测量与评价手段,分析肢体运动对EEG的影响,结果表明通过特定上肢肢体运动干预,引起EEG频率的降低和波幅的升高;左侧肢体运动比右侧肢体运动更能有效地提高对大脑的活化作用;不同肢体部位运动对大脑EEG影响的程度不同,上肢各环节运动对其影响程度的大小依次是指关节的复杂动作———指关节的屈伸运动———腕关节的屈伸运动。     

登山锻炼对小学三年级学生身体素质影响的研究

登山锻炼作为当下较为流行的户外有氧健身运动,其健康价值越来越受到人们的重视。选取湖南省长沙市岳麓区岳南路小学三年级113名学生作为实验对象,分为实验组和对照组,实验组56名同学,对照组57名同学。对实验组进行为期一学年,每周两次的登山训练,对照组则进行常规体育课锻炼。一学年后比较分析两组学生各身体指标的变化及差异,探析登山锻炼对小学三年级学生身体素质的影响。研究表明,登山锻炼对于改善和提高小学三年级学生的心肺功能有明显作用,对小学三年级学生的身体形态、速度素质也能带来积极影响。     

Relationship of tennis play to executive function in children and adolescents

This study evaluated the association between the frequency of tennis play and executive function in children and adolescents. One hundred and six junior tennis players (6–15 years old) participated in this study. Executive function, including inhibitory control, working memory, and cognitive flexibility were evaluated at rest. Females showed better inhibitory control and cognitive flexibility than males. In males, more frequent tennis play was associated with higher basic processing speed and inhibitory control after controlling for age, gender, body mass index (BMI), and tennis experience. More frequent tennis play was associated with better working memory in both males and females after controlling for age, gender, BMI, and tennis experience. Furthermore, longer tennis experience was related to better cognitive flexibility in males after controlling for age, gender, BMI, and frequency of tennis play. These findings suggest that tennis play is associated with the development of three foundational aspects of executive function (i.e. inhibitory control, working memory, cognitive flexibility). Especially, frequent participation in tennis play is related to better inhibitory control and working memory, while longer experience of tennis play is associated with better cognitive flexibility. Although development of inhibitory control and cognitive flexibility is slower in males than in females, the associations between tennis play and inhibitory control and cognitive flexibility appear to be larger in males than in females.     

浅谈运动处方的实施

综述了对运动处方的认识与理解；有氧运动是指4～5min或更长时间进行的全身性的持续运动．强调运动强度和持续时间的组合和频率；局部肌肉运动分为动和静两种运动；注意最大肌力的比例和反复次数的结合；循环训练、健身活动及康复活动等均可作为运动处方应用于健身活动中。     

Effects of cigarette smoking on cardiac autonomic function during dynamic exercise

Abstract

The purpose of this study was to investigate the acute effect of cigarette smoking on cardiac autonomic function in young adult smokers during dynamic exercise. Fourteen healthy young smokers (21.4 ± 3.4 years) performed peak and submaximal exercise protocols under control and smoking conditions. Resting and submaximal beat-to-beat R-R series were recorded and spectrally decomposed using the fast Fourier transformation. Smoking resulted in a significant decrease in work time, [Vdot]O_2peak and peak O₂ pulse (P < 0.05). Heart rate increased at rest and during submaximal exercise after smoking (P < 0.05). The raw high frequency and low frequency power were significantly reduced by smoking, both at rest and during exercise (P < 0.05). The low to high frequency ratio was higher after smoking (P < 0.05). The normalised low frequency power was also significantly increased by smoking, but only at rest (P < 0.05). These data demonstrate that the tachycardic effect elicited by smoking is accompanied by acute changes in heart rate spectral components both at rest and during exercise. Therefore, the cardiac autonomic control is altered by smoking not only at rest, but also during exercise, resulting in reduced vagal modulation and increased sympathetic dominance.