Effect of aerobic capacity on sweat rate and fluid intake during outdoor exercise in the heat

We measured the aerobic capacity, sweat rate and fluid intake of trained athletes during outdoor exercise and examined the relationship between aerobic capacity and thermoregulatory responses at high ambient temperatures. The maximal aerobic capacity ( ) of the subjects, nine male baseball players of college age, was determined by maximal exercise tests on a cycle ergometer. The subjects practised baseball regularly without drinking fluids from 1330 to 1530 hours. After 30 min rest, they played a baseball game with free access to a sports drink at 15°C from 1600 to 1830 hours. At a mean ambient temperature of 36.7 (SEM 0.2)°C, the mean percentage of body mass loss (m _b) and increase of oral temperature (T _o) from 1330 to 1530 hours was 3.47 (SEM 0.12)% and 0.81 (SEM 0.14)°C, respectively. The sweat loss from 1330 to 1830 hours was 56.53 (SEM 1.56)ml · kg^–1 of body mass (M _b) while the mean fluid consumption was 44.78 (SEM 2.39)ml · kg^–1 ofm _b, with recovery of 76.08 (SEM 2.81)% of sweat loss. The was significantly inversely correlated withm _b, fluid intake and rehydration amount, but showed no correlation withT _o. These results would suggest that at a given exercise intensity in subjects with a higher aerobic capacity body temperature is maintained with a lower sweating rate than that in subjects with a lower aerobic capacity.     

Heart period variability of trained and untrained men at rest and during mental challenge

The effect of aerobic training on parasympathetic reactivity to mental stress is unclear. Thus, the parasympathetic response, as assessed by time series analysis of heart period variability (HPV_ts), of 10 trained male runners (trained group), 10 inherently low resting heart rate untrained men (low HR group), and 10 normal resting HR men (control group) at rest and to two mental stressors was examined. Participants completed a mental arithmetic and Stroop task. Resting HPV_ts at high and medium frequencies was significantly greater for the trained and the low HR groups than for the control group. Significantly greater decreases in HPV_ts at the medium frequency during arithmetic recovery were measured for the trained and low HR groups compared with the response of the control group. Significantly greater decreases in HPV_ts at both the the high and medium frequencies during the first two epochs of the Stroop occurred only for the trained and low HR groups. These results suggest that the greater HPV_ts at rest and decline in HPV_ts during and after mental challenge is influenced by both aerobic training and genetic inheritance.     

High-intensity intermittent running training improves pulmonary function and alters exercise breathing pattern in children

We investigated the effects of short duration running training on resting and exercise lung function in healthy prepubescent children. One trained group (TrG) (n = 9; three girls and six boys; age = 9.7 ± 0.9 year) participated in 8 weeks of high-intensity intermittent running training and was compared to a control group (ContG) (n = 9; four girls and five boys; age = 10.3 ± 0.7 year). Before and after the 8-week period, the children performed pulmonary function tests and an incremental exercise test on a cycle ergometer. After the 8-week period, no change was found in pulmonary function in ContG. Conversely, an increase in forced vital capacity (FVC) (+7 ± 4% ; P = 0.026), forced expiratory volume in one second (+11 ± 6% ; P = 0.025), peak expiratory flows (+17 ± 4% ; P = 0.005), maximal expiratory flows at 50% (+16 ± 10% ; P = 0.019) and 75% (+15 ± 8% ; P = 0.006) of FVC were reported in TrG. At peak exercise, TrG displayed higher values of peak oxygen consumption (+15 ± 4% ; P<0.001), minute ventilation (+16 ± 5% ; P = 0.033) and tidal volume (+15 ± 5% ; P = 0.019) after training. At sub-maximal exercise, ventilatory response to exercise was lower (P = 0.017) in TrG after training, associated with reduced end-tidal partial oxygen pressure (P<0.05) and higher end-tidal partial carbon dioxide pressure (P = 0.026). Lower deadspace volume relative to tidal volume was found at each stage of exercise in TrG after training (P<0.05). Eight weeks of high-intensity intermittent running training enhanced resting pulmonary function and led to deeper exercise ventilation reflecting a better effectiveness in prepubescent children.     

Hyperthermia and maximal oxygen uptake in men and women

To compare the effect of hyperthermia on maximal oxygen uptake (O_2max) in men and women, O_2max was measured in 11 male and 11 female runners under seven conditions involving various ambient temperatures (T_a at 50% RH) and preheating designed to manipulate the esophageal (T_es) and mean skin temperatures at O_2max. The conditions were: 25°C, no preheating (control); 25, 35, 40, and 45°C, with exercise-induced preheating by a 20-min walk at ~33% of control O_2max; 45°C, no preheating; and 45°C, with passive preheating during which T_es and were increased to the same degree as at the end of the 20-min walk at 45°C. Compared to O_2max (l·min^–1) in the control condition (4.52±0.46 in men, 3.01±0.45 in women), O_2max in men and women was reduced with exercise-induced or passive preheating and increased T_a, ~4% at 35°C, ~9% at 40°C and ~18% at 45°C. Percentage reductions (7–36%) in physical performance (treadmill test time to exhaustion) were strongly related to reductions in O_2max (r=0.82–0.84). The effects of hyperthermia on O_2max and physical performance in men and women were almost identical. We conclude that men and women do not differ in their thermal responses to maximal exercise, or in the relationship of hyperthermia to reductions in O_2max and physical performance at high temperature. Data are reported as mean (SD) unless otherwise stated.     

Hormonal and metabolic response to three types of exercise of equal duration and external work output

Summary Five normal men, aged 20–30 years, participated in three types of exercise (I, II, III) of equal duration (20 min) and total external work output (120–180 kJ) separated by ten days of rest. Exercises consisted of seven sets of squats with barbells on the shoulders (I; Maximal Power Output _max=600−900 W), continuous cycling at 50 rev · min⁻¹ (II; _max=100−150 W) and seven bouts of intermittent cycling at 70 rev · min⁻¹ (III; _max=300−450 W). Plasma cortisol, glucagon and lactate increased significantly (P<0.05) during the exercise and recovery periods of the anaerobic, intermittent exercise (I and III) but not in the continuous, aerobic exercise (II). No consistent significant changes were found in plasma glucose. Plasma insulin levels decreased only during exercise II. The highest increase in cortisol and glucagon was not associated with the highest , , _max or HR; however it was associated with the anaerobic component of exercise (lactic acid). It is suggested that in exercises of equal duration and total external work output, the continuous, aerobic exercise (II) led to lowest levels of glucogenic hormones.     

Policemen's physical fitness in relation to the frequency of leisure-time physical excercise

Summary Ninety to ninety-five men (aged 27 to 46 years) from the police academy were the study subjects. Their prior habits of physical excercise, estimated aerobic capacity ( ), muscular performance, and thickness of subcutaneous fat were determined. The policemen were taller (181 cm vs 175 cm) and heavier (84 kg vs 74 kg) than the average 20- to 40-year-old Finnish man, and their (1 · min^–1) was higher (3.41 1 · min^–1 vs 2.96 1 min^–1 The frequency of prior physical exercise significantly correlated with most of the variables studied. Those policemen who did not exercise at all (n = 12) were inferior to the average 20- to 40-year-old Finnish man on all the physical fitness tests, whereas the results of the most active policemen (n = 23) were clearly higher. The results indicate that the selection of heavier and taller men for police training guarantees a certain absolute level of physical performance capacity. However, the physical activity involved in police work is insufficient to maintain a high level of physical fitness, which must be achieved through participation in regular and effective physical training.     

Community Based Assessment of Unintentional Injuries in a Community Development Block of Purba Bardhaman District,West

BackgroundInjuries are a focus of public health practice because they pose a serious health threat and are preventable. Currently, injury accounts for 14% of all Disability Adjusted Life Years (DALYs) losses for the world''s entire population. In India, unintentional injuries within the home environment have not so far been recognized to the same extent as traffic and work-related injuries among all age groups. With this background, a community based epidemiological study was conducted with the aim to find out the prevalence and epidemiology of unintentional injuries.MethodsA cross-sectional study was conducted during July 2018 - June 2019 in Bhatar block of Purba Bardhaman District. Cluster random sampling was applied to select required sample of 555 individuals from 24 villages. The study tools used were a predesigned and pretested schedule developed by the researchers with the help of Guidelines for conducting community surveys on injuries by World Health Organization (WHO) and a checklist for assessing household level injury hazard. The study had approval from Institutional Ethics Committee. Chi square test and multivariable logistic regression were performed using SPSS V16.ResultsPrevalence of unintentional injury was 8.8 % in the preceding three months. Multivariable logistic regression revealed that those who were below 18 years of age, severely vulnerable to unintentional injuries and belonged to nuclear families had significantly higher odds of developing unintentional injuries at home.ConclusionUnintentional injury is prevalent in West Bengal. Dissemination of injury prevention information with special focus on household modification is an effective strategy to prevent unintentional injuries.     

尿道下裂修复术的回顾性研究

目的　通过临床研究探讨尿道下裂修复术的手术方式与治疗结果的关系。方法　对 10年来尿道下裂修复术 9种方式和 4种取材的特点进行回顾性分析。结果　除术者的临床经验以外 ,手术方式和取材对治疗效果有重要影响。其成功率为 :隧道式皮管法 86.4% ,带蒂包皮岛瓣法 82 .1% ,膀胱粘膜法 82 .2 %。结论　本组采用的尿道下裂修复术 9种术式和 4种取材各具优缺点 ,其中隧道式皮管法、带蒂包皮岛瓣法和膀胱粘膜法的成功率较高 ,值得深入研究改进。     

内窥镜下电刀内切开治疗输尿管狭窄疗效观察(附36例报告)

目的　探索通过输尿管镜 (UR)及经皮肾镜 (PCN)采用电刀内切开治疗输尿管狭窄的方法与疗效。方法　对 36例 4 1处输尿管狭窄的患者应用自行研制的内切开电刀探头通过输尿管镜 (UR)及经皮肾镜(PCN)行输尿管内切开。结果　 36例均获随访。有效 31例 (86 1% ) ,好转 3例 (8 3% ) ,无效 2例 (5 6 % )。结论　通过输尿管镜及经皮肾镜采用电刀内切开是治疗输尿管狭窄的有效方法 ,治疗效果良好 ,手术创伤小 ,视野清 ,并发症少。     

武警某部女学员有氧耐力训练训练心率的研究

目的为指导和监控部队有氧耐力训练提供参考资料.方法对382名18～22岁女学员依照GJB1337-92和GJB2558-96规定的方法分别测定其安静心率和训练心率.结果安静心率均值为72.85±6.28b/min;按平均年龄21岁计算,中等训练心率为165.76±5.96b/min;最小训练心率为151.17±6.06b/min;最大训练心率为178.23±6.14b/min.结论女学员有氧耐力训练的适宜训练心率为151～178b/min.