Effect of exercise and nasal splinting on static and dynamic measures of nasal airflow

The main aim of this study was to assess the separate and combined effects of exercise and nasal splinting on static and dynamic measures of nasal airflow. In a randomized crossover design, 12 healthy participants (6 men, 6 women) performed static and dynamic spirometric nasal airflow assessment tests, with or without nasal splinting (Breathe-Right?), before and after a maximal oxygen uptake (VO 2max ) treadmill test. At least 7 days later, the V O 2max and nasal airflow tests were repeated. The results showed that the measured variables were not significantly different with and without nasal splinting. We conclude that the absence of significantly enhanced nasal patency observed for nasal splinting and after exercise suggest that these factors have a minimal impact on nasal airflow volume and rate.     

The influence of ventilatory control on heart rate variability in children

The aim of this study was to determine the influence of breathing frequency and tidal volume on resting heart rate variability in children aged 9 years ( n = 29) and 16 years ( n = 19). Heart rate variability was measured in four conditions: (1) without the control of ventilation followed at random by (2) a fixed breathing frequency of 12 breaths· min -1 , (3) a breathing frequency of 12 breaths· min -1 but with a fixed tidal volume of 30% vital capacity and (4) a fixed breathing frequency of 6 breaths·min -1 and a tidal volume of 30% vital capacity. A total of 128 RR intervals (the time between two spikes in the heart rate) were detected and absolute high- and low-frequency spectral components were calculated using autoregressive modelling. The younger children were unable to control ventilation to achieve conditions 3 and 4; therefore, a 2 2 2 (group 2 condition) analysis of variance was used to analyse conditions 1 and 2. There were significant interactions between group and heart rate variability conditions for the low-frequency component and the ratio of low to high frequencies ( P ? 0.001). The main effect for condition showed that at 12 breaths· min -1 with no fixed tidal volume there was a significantly higher standard deviation of the RR interval, total power and high-frequency ( P ? 0.01) and lowfrequency spectral components ( P ? 0.05) than in the condition with no ventilatory control. Across the four breathing conditions for the older participants, the high-frequency spectral component was significantly higher in the condition at 6 breaths· min -1 with a fixed tidal volume than in that with no ventilatory control ( P ? 0.005); the ratio of high to low frequencies was significantly lower for the spontaneous condition than those performed at 12 breaths· min -1 ( P ? 0.001). The results provide evidence of the need for ventilatory control when assessing short-term resting heart rate variability in children.     

如何获得高位置的美妙歌声

高位置的歌唱发声，是歌唱艺术的基本理念和重要技巧之一，是获得美妙歌声的基本途径。有志学习美声唱法或民族唱法的声乐爱好者，必须用心解决高位置的问题。就此，本文提出了一些富有创意的教学见解和形象化的训练构想。     

通向永恒之路——《轻盈的气息》之时间艺术

《轻盈的气息》是第一位获得诺贝尔文学奖的俄罗斯作家蒲宁的代表作品。文章从时间角度切入对其进行解读与分析,具体阐释了时间的有序与无序、运动与静止、现时性与非现时性以及有限与无限,并通过进一步分析呈现出它们之间奇妙地碰撞融合,统观出作品高超的时间艺术。     

Assessment of the lactate and ventilatory thresholds by breathing frequency in runners

The aim of this study was to establish the validity of the breakpoint in breathing frequency for the assessment of the lactate threshold and the ventilatory threshold during incremental running exercise. Twelve trained runners (mean +/- s: age 29 +/- 8 years; body mass 68.7 8.8 kg; V O 2m ax 57.9 +/- 4.1 ml . kg -1 . min -1 ) performed randomly assigned incremental treadmill tests on separate days. In addition to the assessment of the V O 2m ax (Test 1), the subjects performed two standard multi-stage treadmill tests (4-min stages) for the assessment of the lactate threshold while wearing (Test 2) and not wearing (Test 3) a standard mouthpiece and noseclip arrangement. Breathing frequency was measured by a thermistor, which was positioned in the back of the mouthpiece for Test 2, and fixed 3 cm in front of the mouth using a headband and flexible wiring for Test 3. All exercise tests were recorded on videotape and mean breathing frequency and stride rate were calculated for the last minute of each stage from real-time playback of the videotapes. The breathing frequency breakpoint was determined in six subjects only for Test 2 and in five subjects only for Test 3. For Test 2, there were no differences between the breakpoint in breathing frequency (14.7 +/- 0.9 km . h - 1), the lactate threshold (14.7 +/- 0.9 km . h -1 ) and the ventilatory threshold (14.7 +/- 1.1 km . h -1 ). For Test 3, the breakpoint in breathing frequency (14.0 +/- 1.0 km . h -1 ) was not appreciably different from the lactate threshold (14.7 +/- 1.2 km . h -1 ). Hey plots showed marked interindividual differences in the responses of breathing frequency and tidal volume to exercise. In four subjects, the ventilatory threshold was mediated by a non-linear increase in tidal volume, with breathing frequency either increasing in a linear manner (n = 1) or remaining constant owing to entrainment of breathing frequency to cadence (n = 3). We conclude that the breakpoint in breathing frequency does not provide a valid method for the field-based assessment of the lactate or ventilatory thresholds in most subjects for running exercise.     

体育运动中的滞空及其形成机制研究

滞空是篮球、排球、跳远、武术等体育运动项目中常常提到的概念,也是体育运动中确实存在的一种现象,即运动员跳起后人体的头部和上体在空中停留的现象;这一现象曾因看似违背经典力学定律而备受质疑。研究通过梳理相关文献资料并结合运动生理学和运动生物力学相关知识,对滞空现象存在的本质进行了全面的分析,结果表明:滞空现象确实存在也并不违背相关运动学定律;滞空现象是运动员通过巧妙改变自身重心的位置来实现的,其形成机制包括以下三个方面:一、充分利用最高点前后人体纵向速度较小的特点;二、通过运动员肢体的相对运动改变了人体重心的相对位置;三、通过腹式逆呼吸的方法改变身体重心相对位置。     

论歌唱中的呼吸

呼吸是歌唱的根基,也是歌唱的发动机。科学的呼吸方法和技巧是提高歌唱能力的重要前提,而歌唱中的呼吸又不仅仅是生活中的自然呼吸,而是依赖着三个呼吸系统的共同协调。此外,用科学方法理智攻破心理障碍,调节良好的心理状态也是保持正常歌唱呼吸的关键。     

太极拳运动对中老年人运动耐力及肺功能影响分析

通过对太极拳逆腹式呼吸和健步走腹式顺式呼吸的对比,并与未参加锻炼的普通人群对照,从6min步行实验（6MWT）、血氧饱和度（Sa）、肺功能角度探讨太极拳运动对中老年人运动耐力及肺功能的改善与提高情况,为太极拳健身功能提供一定的理论依据.     

太极拳教学中呼吸与动作配合之探讨——以上海体育学院武术基础套路课程为例

文章采用文献资料法、问卷调查法等科研方法,针对上海体育学院武术基础套路课程中学生在练习太极拳中存在的呼吸与动作配合的问题进行分析,提出在太极拳呼吸与动作配合教学中应遵循的几点原则.     

太极拳"内养"方法之研究

中国哲人在“以人为本”、“天人合一”的思维框架中,借助于云气的活动功能与表现方式,对生命之气进行了有益探索,总结出变化气质,以实现精神与肉体的双重超越为目的的内修理论与方法：太极拳吸取了这一研究成果,根据自身的需要,对劲力的活动方式展开了讨论,研究出以内劲为基础的太极劲修炼方法与进展步骤。