Effect of 30% Oxygen Administration on Verbal Cognitive Performance, Blood Oxygen Saturation and Heart Rate

This study investigated the effect of 30% oxygen administration on verbal cognitive performance, blood oxygen saturation, and heart rate. Five male (24.6(±0.9) years) and five female (22.2(±1.9) years) college students were selected as the subjects for this study. Two psychological tests were developed to measure the performance level of verbal cognition. The experiment consisted of two runs: one was a verbal cognition task, with normal air (21% oxygen) administered and the other was with hyperoxic air (30% oxygen) administered. The experimental sequence in each run consisted of Rest 1 (1 min), Control (1 min), Task (4 min), and Rest 2 (4 min). Blood oxygen saturation and heart rate were measured throughout the four phases. The results of the verbal behavioural analysis reveal that accuracy rates were enhanced with 30% oxygen administration compared to 21% oxygen. When 30% oxygen was supplied, blood oxygen saturation was increased significantly compared to that with 21% oxygen administration, whereas heart rate showed no significant difference. Significant positive correlations were found between changes in oxygen saturation and cognitive performance. This result supports the hypothesis that 30% oxygen administration would lead to increases in verbal cognitive performance.     

Effect of lowered muscle temperature on the physiological response to exercise in men

The effect of low muscle temperature on the response to dynamic exercise was studied in six healthy men who performed 42 min of exercise on a cycle ergometer at an intensity of 70% of their maximal O2 uptake. Experiments were performed under control conditions, i.e. from rest at room temperature, and following 45 min standing with legs immersed in a water bath at 12 degrees C. The water bath reduced quadriceps muscle temperature (at 3 cm depth) from 36.4 (SD 0.5) degrees C to 30.5 (SD 1.7) degrees C. Following cooling, exercise heart rate was initially lower, the mean difference ranged from 13 (SD 4) beats.min-1 after 6 min of exercise, to 4 (SD 2) beats.min-1 after 24 min of exercise. Steady-state oxygen uptake was consistently higher (0.2 l.min-1). However, no difference could be discerned in the kinetics of oxygen uptake at the onset of exercise. During exercise after cooling a significantly higher peak value was found for the blood lactate concentration compared to that under control conditions. The peak values were both reached after approximately 9 min of exercise. After 42 min of exercise the blood lactate concentrations did not differ significantly, indicating a faster rate of removal during exercise after cooling. We interpreted these observations as reflecting a relatively higher level of muscle hypoxia at the onset of exercise as a consequence of a cold-induced vasoconstriction. The elevated steady-state oxygen uptake may in part have been accounted for by the energetic costs of removal of the extra lactate released into the blood consequent upon initial tissue hypoxia.     

长期太极拳运动对中老年人膝关节皮肤微血管反应性、经皮氧分压的影响*

目的: 探讨长期太极拳运动对中老年人膝关节皮肤微血管反应性、经皮氧分压的影响。方法: 以湖北省恩施州土家族苗族自治州太极拳爱好者协会26名系统练习(每周至少练习三次,每次不少于90 min)太极拳超过2年的成员为运动组(54.6± 4.0)岁,26名同年龄段健康的普通人为对照组(53.2±5.1)岁,两组受试者男女比例均为1∶1。使用第六代(最新一代)激光多普勒血流检测仪(PF6010)对研究对象膝关节表面中心的皮肤进行检测,测试指标包括血细胞平均运动速度(AVBC)、运动血细胞浓度(CMBC)、微血管血流灌注量(MBP)、经皮氧分压(TcpO2)。其中AVBC、CMBC、MBP先进行5 min的基础值测试(基础值),然后将测试探头加热到44℃并持续10 min(加热后值),TcpO2测试值为探头直接加热到44℃值。结果: 与对照组相比,运动组的MBP基础值有所降低,但无统计学意义(P＞0.05);MBP的加热后值与增加率显著升高(P＜0.05),CMBC的增加率显著降低(P＜0.05),AVBC的增加率显著升高(P＜0.05),TcpO2有所升高,但无统计学意义(P＞0.05)。结论: 长期系统的太极拳运动可提高中老年人膝关节皮肤微血管的反应性和经皮氧分压。