Lung Volumes and Maximal Respiratory Pressures in Collegiate Swimmers and Runners

Abstract

To determine whether respiratory muscle strength is related to pulmonary volume differences in athletes and nonathletes, 11 intercollegiate female swimmers, 11 female cross-country runners, and two nonathletic control groups, matched to the athletes in height and age, were evaluated for pulmonary parameters including maximal inspiratory pressure (P_lmax) and maximal expiratory pressure (P_Emax). Swimmers exhibited larger (p < .05) vital capacities (VC), residual lung volumes (RV), inspiratory capacities (IC), and functional residual capacities (FRC) than both the runners or the controls but no difference (p > .05) in either P_lmax or inspiratory flow (FIV_25%-75%). Timed expiratory volumes (FEV Q.5 m and FEV_1.0 were significantly (p < .05) lower in the swimmers than in the controls. These data suggest that an adaptational growth may be responsible, in part, for the augmented static lung volumes demonstrated in swimmers     

吸气肌训练对常氧和低氧条件下运动呼吸功能的影响

目的:检测吸气肌训练(IMT)对常氧和低氧条件下运动效果的影响;方法:15名受试者用呼吸肌训练仪进行为期4周的训练,其中,对照组8人,采用15%PImax(最大吸气口腔压力);训练组7人,采用50%PImax。训练前后,在低氧和常氧条件下分别进行85%V.O2max的跑台力竭测试及功能测试;结果:IMT组PImax增加24.5%±3.1%。所有条件下力竭时间均未见改变。IMT组在常氧和低氧运动后呼吸肌疲劳均减少10%(P<0.05);在低氧条件下运动,V.O2减少8%～12%(P<0.05),心输出量减少14%±2%,通气量减少25%±3%;动脉血氧饱和度和肺扩散能力分别增加了4%±1%和22%±3%;结论:IMT可以明显改善低氧条件下运动的呼吸功能。     

运动性疲劳状态下大鼠骨骼肌线粒体呼吸链还原酶活性的研究

目的:研究运动性疲劳状态下,大鼠骨骼肌线粒体呼吸链还原酶复合体活性的变化,进一步探讨骨骼肌运动性疲劳发生的可能机制。方法:以健康雄性Wister大鼠为实验对象,随机分为安静对照组、大强度运动组和中等强度运动组,分光光度法测定线粒体呼吸链酶复合体(Ⅰ~Ⅲ)活性。结果:与安静对照组相比,大强度运动组CⅠ和CⅡ的活性显著性升高(P<0.01),分别升高63.56%和66.64%;CⅢ的活性显著性下降(P<0.01),下降32.20%;中等强度运动组CⅠ和CⅡ的活性显著性升高(P<0.01),分别升高254.24%和59.29%;CⅢ的活性显著性下降(P<0.01),下降30.51%。与大强度运动组相比,中等强度运动组CⅠ的活性显著性上升(P<0.01),上升116.58%,CⅡ和CⅢ的活性无显著性差异。结论:无论是大强度运动还是中等强度运动,在疲劳状态下,骨骼肌线粒体呼吸链还原酶活性都发生不同程度的变化。CⅠ和CⅡ活性显著增加可能是由于运动时能量需求量大,机体代谢过程中底物NADH和琥珀酸量增多引起的,而CⅢ活性明显降低可能与电子漏,CoQ自氧化产生自由基,内膜流动性下降等因素有关。中等强度持续运动对CⅠ活性的影响程度比大强度间歇运动更深远,这可能是运动方式不同所致。     

针柱诱导铝表面冷凝液滴聚并的实验研究

采用实验研究得到针柱接触铝板表面后冷凝液滴的变化情况,分析不同规格针柱在不同时刻接触铝板表面后诱导生成的液滴半径的大小及清理干净区域的半径的变化规律,并测量温度变化,计算得到热流密度及换热系数随时间的变化规律,分析针柱接触铝板对热流密度和冷凝换热系数的影响。     

有氧运动协同抗氧化剂对老年小鼠肾脏线粒体质和量的影响

目的:研究小鼠衰老时肾脏线粒体形态、结构、功能及mtDNA的变化规律,观察有氧运动训练和抗氧化剂延缓肾脏老化的效果.方法:用电镜对线粒体观察计数,Clark氧电极法测定线粒体呼吸链CytC氧化酶及NADH脱氢酶活性,分光光度法测定抗氧化酶活性,聚合酶链反应检测mtDNA3866bp片段缺失率.结果:与5月龄小鼠比较,20月龄的老年小鼠肾脏线粒体数量减少、体积增大,线粒体呼吸控制率、ADP/O比值减小,呼吸链NADH脱氢酶、CytC氧化酶活性下降,mtDNA3866bp片段缺失率增加,而抗氧化酶活性却增大.结论:长期进行有氧运动和/或补充抗氧化剂可在一定程度上维持机体氧化与抗氧化的平衡,延缓mtDNA片段缺失率随增龄积累,预防线粒体老化,改善线粒体功能.     

呼吸肌疲劳对运动能力的影响

迄今为止,人们比以往任何时候都相信,呼吸系统是影响耐力的重要因素之一。不仅剧烈的耐力练习会导致呼吸肌的疲劳,而且运动训练和比赛所导致的呼吸肌的疲劳也会影响运动员的竞技状态。因而运动员进行呼吸肌的耐力训练可以提高其耐力水平。勿庸置疑,呼吸系统的疾病可以影响运动能力,但是呼吸系统在何种程度上影响运动能力仍然有争议。     

不同专项运动员递增负荷运动中氧通气当量和最佳呼吸效率点的观察

测定了篮球、中长跑、短跑、武术套路运动员在递增负荷运动中氧通气当量的变化曲线,并确定了最佳呼吸效率点.结果发现,不同专项运动员的氧通气当量有相似的变化规律,随着运动强度的增加,运动时间的延长,氧通气当量先略下降,在运动负荷达到150W时降低到一个最低值即最佳呼吸效率点,然后逐渐上升.结果提示,氧通气当量和最佳呼吸效率点可作为无氧阈深入研究的一种辅助手段,最佳呼吸效率点时的强度亦可作为有氧训练的界限强度.     

Return to play after acute infectious disease in football players

Abstract

Acute infectious diseases are common in athletes and can impair their ability to train and to compete. Furthermore, continuing exercise during infectious diseases may lead to prolongation or aggravation of illness with severe acute or chronic organ manifestations. Therefore, even simple infectious diseases require a sufficient period of convalescence and recovery, during which exercise may be not allowed. Nowadays, especially in professional football with high pressures on players, staff and clubs due to broad public interests as well as financial constraints, the return-to-play decision is of utmost significance. Based on previous suggestions and our own experience within amateur and professional athletes and football players, this article aims to give a short overview on return-to-play decisions after common acute infectious diseases in football players.     

Ventilatory acclimatisation is beneficial for high-intensity exercise at altitude in elite cyclists

Aim: The aim of this study was to examine the relationship between ventilatory adaptation and performance during altitude training at 2700?m. Methods: Seven elite cyclists (age: 21.2?±?1.1?yr, body mass: 69.9?±?5.6?kg, height 176.3?±?4.9?cm) participated in this study. A hypoxic ventilatory response (HVR) test and a submaximal exercise test were performed at sea level prior to the training camp and again after 15 d at altitude (ALT15). Ventilation (V_E), end-tidal carbon-dioxide partial pressure (P_ETCO₂) and oxyhaemoglobin saturation via pulse oximetry (SpO₂) were measured at rest and during submaximal cycling at 250?W. A hill climb (HC) performance test was conducted at sea level and after 14 d at altitude (ALT14) using a road of similar length (5.5–6?km) and gradient (4.8–5.3%). Power output was measured using SRM cranks. Average HC power at ALT14 was normalised to sea level power (HC%). Multiple regression was used to identify significant predictors of performance at altitude. Results: At ALT15, there was a significant increase in resting V_E (10.3?±?1.9 vs. 12.2?±?2.4?L·min^?1) and HVR (0.34?±?0.24 vs. 0.71?±?0.49?L·min^?1·%^?1), while P_ETCO₂ (38.4?±?2.3 vs. 32.1?±?3.3?mmHg) and SpO₂ (97.9?±?0.7 vs. 94.0?±?1.7%) were reduced (P?V_E at altitude as significant predictors of HC% (adjusted r²?=?0.913; P?=?0.003). Conclusions: Ventilatory acclimatisation occurred during a 2 wk altitude training camp in elite cyclists and a higher HVR was associated with better performance at altitude, relative to sea level. These results suggest that ventilatory acclimatisation is beneficial for cycling performance at altitude.     

Hepatitis during respiratory syncytial virus infection – a case report

Introduction:

Respiratory syncytial virus (RSV) infection is the most common cause of hospitalization in infants and small children. The aim was to present a 13-months old boy diagnosed with acute airway infection, acute otitis media (AOM) and hepatitis during the RSV-infection.

Material and methods:

Serum catalytic activities of alkaline phosphatase (ALP), aspartate aminotranspherase (AST), alanine aminotranspherase (ALT), gamma glutamyl transpherase (GGT), lactate dehydrogenase (LD), and concentrations of bilirubin were monitored during hospitalization and at control examination.

Results:

The child had clinical signs and symptoms of respiratory failure, AOM, and laboratory findings of virus infection and liver disease. On admission, catalytic activities of enzymes were markedly increased, especially the activity of ALP (10333 U/L, i.e. 24-fold increase in comparison with the upper reference limit). The highest increased in AST (339 U/L, 4.5-fold), ALT (475 U/L, 10.3-fold) and LD (545 U/L, 1.5-fold) were registered on the 3^rd day, and the highest increase in GGT (68 U/L, 3.1-fold) occurred on the 11th day. Seven weeks after discharge AST, ALT, GGT and LD decreased into reference range, and ALP remain mildly increased (478 U/L, 1.1 fold increase). RSV was confirmed in nasal lavage fluid.

Conclusion:

Laboratory results in patient with RSV infection needs to be interpreted in the light of both, respiratory and extrapulmonary manifestations of the infection, respectively.