Ratings of perceived exertion (RPE) as an index of aerobic endurance during local and general exercises

The main purpose of this study was to assess the correlations of RPE with indicators of endurance (critical power), exhaustion time and the electromyographic activity of a relevant muscle during general and local exercises. Eight healthy subjects participated in the study. During the first session, Maximal Aerobic Power (MAP) was measured by means of an incremental cycling exercise on a Monark ergometer. At 1-week intervals the participants performed a general or local exhausting exercise, which consisted of a cycle exercise (60, 73, 86 or 100% MAP) and a knee extension exercise (lifting a load between 17.5 and 32.5 kg every 3 s), respectively. The critical powers corresponding to cycling (CP_cycling) and knee extension (CP_knee) were calculated from the slope of the linear relationship between exhaustion time (t _lim) and work. Rate of perceived exertion, concerning the whole body (overall RPE [RPE_ov]), RPE concerning the exercising muscles (muscular RPE [RPE_mu]) and exhaustion time were measured. During the last session, the integrated electromyogram of the right Vastus Lateralis (iEMG s^?1) was measured during short (20 s) cycling and knee extension nonexhausting exercises, with the same electrode location, at the different power outputs used during the exhausting exercises. The relationships between RPE_mu at the fifth minute and log t _lim and between iEMG% (percentage of the iEMG s^?1 corresponding to 100% MAP during cycling) and log t _lim were similar for the cycling and knee extension exercises. The mean values of RPE_mu at the fifth minute of exercise calculated for CP_cycling and CP_knee were almost equal (12.3 ± 1.7 versus 12.2 ± 0.9). Similarly, the mean values of iEMG% corresponding to CPcycling and CPknee were equal (78.44 versus 79.02%). These results suggest that RPE_mu is related to aerobic endurance and that the possibility of sustaining a high percentage of maximal aerobic power during a general exercise is mainly related to local muscular factors.     

高职院校体育课程改革初探

高等职业教育以满足国家和社会需求为目标，以能力培养为重点。学校体育作为学校教育的重要部分，课程建设与改革不能脱离学校的培养目标，通过对休育课程的改革，实现优化体育教育的目标。     

Changes in physical capacity as a function of age in heavy manual work

The objective of this study was to assess the changes in the physical capacity as a function of age in power line technicians (PLTs). The physical test was designed to closely represent the essential physical tasks of the occupation that were identified through a detailed job demand analysis. The results from the physical test showed that six out of nine test variables did not demonstrate a statistical difference between the mean scores of young (? 39 years) and old age (50 + years) groups. However the older group scored significantly lower in the aerobic capacity test, one-handed pull down, and both right and left standard handgrip tests. Despite these differences the older PLT appears to meet and exceed the physical requirements necessary to carry out the essential tasks of this trade. However a physical test with a high level of content and construct validity is necessary to accurately evaluate the workers physical capacity in relation to the job demands. Based on the principal of specificity for muscle training and testing, this study has demonstrated that heavy manual work appears to maintain physical capacity specific to the task as age progresses.     

Decreased submaximal oxygen uptake during short duration oral contraceptive use: a randomized cross-over trial in premenopausal women

Long-term oral contraceptive (OC) use is known to be associated with changes in haemostasis, cardiovascular dynamics, and carbohydrate and lipid metabolism. Less well documented are the short-term variations in cardiorespiratory responses to exercise during the menstrual cycle of OC users. In this study the short-term effects of the usage of OC on cardiorespiratory and ventilatory responses to submaximal exercise were examined. Ten women (age= 23 ± 3 years) on monophasic OC were tested at three different times during their ‘cycle’ : during menstruation, off OC use (off OC: days 2 –; 4), early on OC use (EOC: days 7 – 9) and late on OC use (LOC: days 19 – 21). Times of testing were assigned randomly. On each occasion participants performed a continuous 12-min run exercise on a treadmill at three submaximal intensities (averaging 7, 8 and 9 km h^?1), each for 4 min. Heart rate, ventilation ([Vdot]E), oxygen uptake ([Vdot]O₂), carbon dioxide output ([Vdot]CO₂), respiratory exchange ratio and running economy were assessed in the last minute of each stage of exercise. No significant variations were observed between the different times for heart rate, [Vdot]E, and [Vdot]CO₂ irrespective of the stage of exercise (p > 0.05). Using two-way analysis of variance (ANOVA) with repeated measures on both factors (three stages and three times), [Vdot]O₂ (ml kg^?1 min^?1) was lower by 3% to 5.8% when participants were on early and late OC use compared to off OC regardless of the stage of the exercise (F(2,18)= 6.3; p= 0.008). Running economy (ml O₂ kg^?1 km^?1) was significantly improved (lower values) when women were on late OC use compared to off OC regardless of the stage of exercise. No significant interaction effect between stage of exercise and time of pill usage was demonstrated in any of the parameters studied. Results suggest that oral contraceptive users may expect lower [Vdot]O₂ and better running economy during the pill ingestion phase and consequently have implications for exercise performances.     

The effect of work-rest schedules and type of task on the discomfort and performance of VDT users

Consideration of the literature survey indicates that video display terminal (VDT) operators tend to have a high incidence of musculoskeletal problems, visual fatigue, and job stress. Although a number of ergonomic improvements in workstation design and work environment can help to reduce these problems, a proper work-rest schedule deserves consideration since it is easily applicable and inexpensive. The objective of this study was to compare the work-rest schedules for VDT operators considering data entry and mental arithmetic tasks. An experiment was conducted with 10 male college students as participants. The methodology included a discomfort questionnaire and performance measures. The independent variables were the work-rest schedule (60-minute work/10-minute rest, 30-minute work/5-minute rest, and 15-minute work/micro breaks) and the type of task (data entry and a mental arithmetic task). The results were analysed using multiple analysis of variance followed by separate analyses. The 15/micro schedule resulted in significantly lower discomfort in the neck, lower back, and chest than the other schedules for data entry task. The 30/5 schedule followed by 15/micro schedule resulted in the lowest eyestrain and blurred vision. Discomfort in the elbow and arm was the lowest with the 15/micro schedule for the mental arithmetic task. The 15/micro schedule resulted in the highest speed, accuracy, and performance for both of the tasks, compared with the 60/10 and 30/5 schedules. The data entry task resulted in significantly increased speed, accuracy, and performance, and lower shoulder and chest discomfort than the mental arithmetic task.     

A feasibility study on a robotic exercise system for mdof physical rehabilitation therapy

This paper presents a robot system developed for medical purpose. A 6-degree-of-freedom robot was introduced for physical exercise and rehabilitation. This system was proposed for stroke patients or patients who cannot use one of their arms or legs. The robot system exercises the hemiplegic part based on the motion of normal part of a patient. Kinematic studies on the human body and robot were applied to develop the robotic rehabilitation exercise system. A clamp which acts as an end effector of the robot to hold a patient was designed and applied to the robot to guarantee the safety of patients. The proposed robotic rehabilitation system was verified by simulations and experiments on arm (elbow and shoulder) motion. Patients are expected to be able to exercise various motions by themselves with the proposed robotic rehabilitation system.     

空气流动对室内健康体育运动人体热舒适的影响及设计策略研究

本文通过实验室实验、主观问卷和能耗模拟的方法,研究室内健康体育运动中空气流动对运动状态下人体热舒适的影响及其节能效果,得出以下结论：运动状态下人体对温度和风速均有更大的接受和适应范围;运动强度增加时对风速的需求增加,气流可通过增加人体表面蒸发和对流散热量而补偿环境温度的升高,在保证人体舒适的同时显著节约建筑制冷能耗。基于以上结论探讨了采用空气流动时室内健康体育运动空间热环境设计和改进策略。     

高校公共体育课运动负荷研究

本讨论了在高校扩招情况下如何应用负荷价值阈理论保证教学质量的问题,以及掌握负荷标准与体育课改革和建设的关系。