优秀游泳运动员肺功能损伤敏感指标及其影响因素

目的:探讨优秀游泳运动员肺功能损伤的敏感指标及其影响因素,为有效监测并改善游泳运动员肺功能损伤提供依据。方法:选取优秀游泳运动员117名(男56人,女61人)进行肺通气功能检测。检测地点为国家体育总局游泳馆(86人)和国家体育总局运动医学研究所体育医院实验室(31人),测试指标包括用力肺活量(FVC)、第一秒用力呼气标准容积(FEV1)、1秒率(FEV1/FVC)、用力呼气流量50%(FEF50)、用力呼气流量75%(FEF75)。根据中华医学会标准对上述运动员的肺功能情况作出诊断,分析与游泳运动员肺损伤密切相关的敏感指标;分析比较不同场所测得肺通气功能障碍发生率的差异,并对不同场所测得FVC、FEV1/FVC进行对比分析;将FEV1、FEV1/FVC与运动员训练年限进行相关性分析。结果:(1)FEV1/FVC与优秀游泳运动员肺通气功能障碍的发生密切相关;(2)游泳运动员在游泳馆所测肺通气功能障碍的发生率显著低于实验室;游泳馆和实验室所测FVC无显著性差异(P>0.05),游泳馆FEV1/FVC则极显著大于实验室(P<0.01);(3)FEV1%(FEV1实测/预计值%)、FEV1/FVC均与训练年限呈显著负相关(r1=-0.247,P=0.025;r2=-0.224,P=0.043)。结论:FEV1/FVC可作为优秀游泳运动员肺功能损伤评估的敏感指标,该指标受测试环境和训练年限的影响,训练年限越长的游泳运动员越易导致肺功能受损。     

中国优秀运动员肺功能调查与分析

目的:了解中国优秀运动员肺功能水平并探讨长期不同运动训练对呼吸系统的影响。方法:2004年6月～11月,对10个不同项目运动队147名运动员进行肺通气功能测试,包括最大分钟肺通气量(MMV)、用力肺活量(FVC)、用力呼气一秒量(FEV1)、用力呼气一秒率(FEV1/FVC)、呼气峰流速(PEF)、用力呼气流速(FEF)和最大中段呼气流速(MMF),分析不同项目运动训练对运动员肺功能的影响。结果:各项目运动员FVC、FEV1/FVC有显著性差异(P<0.05)。游泳、球类、力量项目运动员FVC及FEV1优于其他项目,游泳项目运动员FVC/BMI及FEV1/BMI最高。各项目运动员小气道功能实测值有显著性差异(P<0.05);游泳项目运动员MMF、FEF50和FEF75实测值均低于其他类型运动员,其实测值/预计值分别为72%、70%、78%;耐力项目运动员MMF、FEF50和FEF75实测值/预计值也低于正常,分别为79%、75%和99%。结论:不同项目运动员肺功能之间存在差异;游泳运动员肺功能高于其他类型运动员;部分长期从事游泳和耐力训练运动的运动员存在小气道功能受损。     

脉冲振荡气道阻力测定对运动员肺功能异常诊断价值的研究

目的:探讨脉冲震荡技术(IOS)气道阻力测定对运动员肺功能异常的诊断价值。方法:对中国国家队398名运动员进行常规肺功能检查并采用脉冲震荡技术(IOS)进行气道阻力测定。按照常规肺功能测试结果将受试运动员分为肺功能正常组、阻塞性通气功能障碍组及小气道功能减弱组。结果:(1)IOS气道阻力参数气道总阻抗(Z5)、气道总粘性阻力(R5)、近端气道粘性阻力(R20)与慢肺活量(VC)、一秒用力肺活量(FEV1)、一秒率(FEV1/FVC%)、25%肺活量时的最大呼气流量(FEF75%)、50%肺活量时的最大呼气流量(FEF50%)均存在负相关(P<0.05);周边弹性阻力(X5)与VC、FEV1、FEF50%、FEF75%呈正相关(P<0.05)。(2)与肺功能正常组运动员比较,阻塞性通气功能障碍组及小气道功能减弱组的Z5、R5、R20均显著高于肺功能正常组(P<0.05),X5%显著低于肺功能正常组(P<0.05)。结论:脉冲振荡气道阻力测定可以作为运动员肺功能检测和治疗监测的有效方法。肺功能异常运动员总气道阻力增高,主要表现为中心气道粘性阻力增高同时伴有肺顺应性下降。     

在校体能训练对飞行学员肺功能的影响

目的观察在校体能训练对飞行学员肺功能的影响。方法采用肺功能检测仪,对136名在校飞行学员体能训练2年前后肺功能进行测定。结果 1在校飞行学员体能训练2年后,用力肺活量和第一秒用力呼气容积占预计值百分比与训练前比较均有显著提高(P<0.05);小气道功能(MMEF、FEF50%、FEF75%)占预计值百分比与训练前比较变化差异无统计学意义(P>0.05)。2体能训练前,136名飞行学员中肺通气功能障碍者15例,占总数的11.0%。15例肺通气功能障碍者均为轻度,其中阻塞性通气功能障碍者11例,限制性通气功能障碍者4例,无混合性通气功能障碍。经过2年体能训练后,3例阻塞性通气功能障碍者肺通气功能恢复正常,8例仍存在阻塞性通气功能障碍。4例限制性通气功能障碍者肺通气功能均恢复正常。3体能训练前有2例飞行学员存在小气道功能障碍,经过体能训练2年后小气道功能均恢复正常。结论在校体能训练可提高飞行学员肺通气功能,提示在校体能训练对提高大气道功能有重要意义,部分小气道功能亦可逆转,体能训练对小气道功能的影响有待进一步深入研究。     

Astograph法测定咳嗽变异型哮喘患者的气道高反应

 目的 比较52例咳嗽变异型哮喘患者(CVA)和35例健康人支气管激发试验和肺功能指标,并分析两指标间的相关性.方法 气道反应性测定使用Astograph J-21,数据分析采用SPSS 11.0软件包,统计方法为方差分析、t检验、多重线性和逐步回归.结果 126例胸部X片无明显异常的慢性咳嗽患者中,CVA确诊率为41.3%(52/126),激发试验阳性率100%(52/52),健康组激发试验阳性率0(0/35).临床常用的指标PEF(L/s)、FEVl(L),组间差异有统计学意义(P＜0.01),但反映小气道水平的MMEF、P50等指标组间差异更为显著.回归发现Dmin与P50、FEV1和BMI指数相关,PD35指标与P50、MMEF改善率、FEV1改善率及BMI指数相关.结论 MMEF、P50等小气道指标要较PEF、FEV1更能体现两组间肺功能指标的差异,对CAV的诊断更具临床意义.     

中国优秀运动员肺功能及相关因素分析

目的:了解中国优秀运动员参加大赛前的肺功能状况与相关因素的影响。方法:对参加2006年多哈亚运会的中国国家队285名运动员(共4个项群、27个运动项目)进行了系统肺功能检测与相关因素问诊。结果:(1)全体受检运动员中出现肺通气功能异常者78名,小气道功能减弱者59名,两项共137名,占受检总数的48.1%,尤以耐力类项群和对抗类项群居多,且VC、FVC、FEV1/FVC%各项群间存在显著性差异(P<0.01)。(2)既往患肺炎、支气管炎运动员的FEV1/FVC%、MEF50%及MEF25%显著低于既往其他疾病组和无既往疾病组(P<0.05),且肺通气功能异常及小气道功能减弱者百分比也高于另两组运动员。结论:中国优秀运动员的肺功能异常主要与项群特点有关,既往肺炎、支气管炎病史也对其具有一定提示作用。     

职业性接触粉尘工人不同结局的肺通气功能比较

目的比较职业性接触粉尘导致的不同结局工人肺通气功能及小气道损伤状况,为早期诊断职业性呼吸疾患提供依据。方法选取某矿煤工尘肺患者80例,尘肺合并结核33例,以及无尘肺矿工177例为接触粉尘后的三种不同结局。分别测定各结局对象的肺功能,指标包括FVC、FEV1、FEV1/FVC、V50、V25、MMEF,以实测值占预计值百分比进行比较分析。结果比较各组肺功能各指标实测值占预计值的百分比,尘肺合并结核组各指标显著低于其他两组(P<0.01),单纯尘肺组在FVC%、FEV1%和FEV1/FVC%上损伤分级均属正常(>80%);各组肺通气功能损伤级别构成差异有统计学意义(P<0.01),其中尘肺合并结核组肺功能在中重度损伤的比例显著高于其他组,而无尘肺组正常的肺功能级别比例显著高于其余两组(P<0.01)。小气道指标(V50%,V25%)在尘肺合并结核组和尘肺组显著减低。结论职业性接触粉尘导致的尘肺及尘肺合并结核肺通气功能显著减低;小气道功能对职业性接触粉尘肺功能损伤较敏感,对职业性接触粉尘工人有早期预警作用。     

温泉游泳训练对飞行员肺功能影响的研究

观察健康疗养期间温泉游泳训练对飞行员肺功能指标的影响。方法：24名现役飞行员在健康疗养期间,进行每周5d、连续4周的温泉游泳训练。训练前后采用采用肺功能检测仪检测肺功能指标。结果：与训练前相比,游泳训练4周后飞行员用力肺活量（FVC）、最大自然换气量（MVV）、呼出峰值流量（PEF）、慢吸气肺活量（IVC）、慢呼出肺活量（VC）、训练前后均有显著变化（P〈0．01）;小气道功能训练前后没有显著变化。结论：健康疗养期间,温泉游泳锻炼可提高肺活量,但对小气道功能的改变不明显。     

招飞学员肺功能现状调查及分析

目的了解高中生招飞学员肺功能水平,为飞行员选拔提供依据。方法对2011年招飞初检合格的169名应届高中毕业生进行肺功能测定。测定指标包括常规肺容量、常规通气量指标。结果①肺功能指标完全正常者97例,占57.40%。72例异常肺功能的测试者中,单纯肺容量指标异常者52例,占72.22%。所有受试者肺活量(VC)均在正常范围之内。②肺通气量下降(FEV1/FVC<80%预计值,且FEV1%<80%预计值为标准)8例,发生率占肺功能异常者11.11%,明显低于肺容量异常的测试者(P<0.05)。③单纯小气道功能下降者(以MMEF、FEF50%、FEF75%三者均<80%预计值为标准)9例,占肺功能异常者的12.50%,明显低于肺容量异常的测试者(P<0.05),但和通气量下降者相比差异无显著性(P>0.05)。④肺容量和肺通气量同时异常者共3例,占肺功能异常者的4.17%,发生率显著低于单纯肺容量下降者、肺通气量下降者及小气道功能下降者(P<0.05)。结论①招飞初检合格者中部分学员肺功能下降;其中以肺容量指标VT、IRV下降较为突出,推测与当代高中生活动量少、体育训练不足有关。通气功能下降者发生率较低,表现为大、小气道功能均有下降,大、小气道功能下降一般多伴随有呼吸系统症状。②在目前招飞体检中,肺功能检查非常规检查项目,仅对呼吸系统疾病史进行询问及胸片检查,不足以鉴别和发现肺功能良好及肺功能异常的学员。如在招飞体检中纳入肺功能检查,并根据其肺功能状况不同,分别给予选择性的训练计划,可提高出飞率,减少停飞率,对提高飞行适应性有着重要意义。     

CT血管成像对COPD支气管动脉变化与肺功能关系的研究

目的 利用CT血管成像技术(CTA)研究慢性阻塞性肺疾病(COPD)患者支气管动脉的显示及支气管动脉管径与肺功能(PFT)指标间的关系,探索COPD支气管动脉变化与气道重塑的关系.方法 回顾性分析43例COPD患者的支气管动脉CTA图像,利用多平面重组(MPR)、最大密度投影(MIP)及容积再现(VR)对患者支气管动脉重建,统计支气管动脉支数,评价支气管动脉的显示情况,测量肺门水平各支支气管动脉管径,并分析支气管动脉管径与肺功能指标(FEV1,FEV1％,FVC,FEV1/FVC)的关系.结果 共显示支气管动脉102支.左支气管动脉41支(40.2％),平均管径1.51 mm.右支气管动脉61支(59.8％),平均管径1.98 mm.右支气管动脉管径较左侧粗,具有统计学意义(P=0.001).右支气管动脉管径与肺功能指标FEV1(r=-0.468,P＜0.001)、FEV1％(r=-0.476,P＜0.001)、FVC(r=-0.381,P=0.002)、FEV1/FVC(r=-0.468,P＜ 0.001)均呈负相关.左支气管动脉管径与FEV1(r=-0.314,P=0.046)、FEV1％(r=-0.357,P=0.022)呈负相关,与FVC(r=-0.265,P=0.094)及FEV1/FVC(r=-0.284,P=0.072)无显著相关性.结论 CTA可清晰显示COPD患者支气管动脉.右支气管动脉管径较左侧粗.右支气管动脉管径均与肺功能指标呈负相关.左支气管动脉管径与FEV1、FEV1％预呈负相关,说明支气管动脉与COPD的气道结构重塑关系密切.     

Airway cells after swimming outdoors or in the sea in nonasthmatic athletes

BACKGROUND: Marathon runners and elite swimmers showed increased inflammatory cells in the airways at baseline. Although airway neutrophils increase further after a marathon race, the airway response to swimming is unknown. The aim of this study was to assess the effects of swimming on airway cells. To avoid the concomitant effects of chronic exposure to chlorine, the study was conducted in seven nonasthmatic swimmers [mean age (SD): 23.3 +/- 7.7 yr, training: 32 +/- 15 km.wk-1] habitually training in an outdoor pool (OP), i.e., a low-chlorine environment. METHODS: Spirometry, exhaled nitric oxide (NO), induced sputum, and peripheral blood samples were obtained at baseline, after a 5-km trial in OP, and after a 5-km race in the sea (S), i.e., hypertonic airway exposure. RESULTS: Airway neutrophil differential counts at baseline were higher in swimmers than in sedentary controls (N = 10), but cell counts, neutrophil elastase, and eosinophil cationic protein were unaffected by 5-km swimming. After swimming, L-selectin expression on airway cells decreased, suggesting exercise-induced cell mobilization into the airways and/or direct effects of hyperventilation on airway cells. After S, airway eosinophil differential counts increased slightly. Exhaled NO concentration was 19 +/- 6 ppb at baseline, 8 +/- 4 ppb after OP, and 21 +/- 7 ppb after S (P < 0.005 for OP vs baseline and S). CONCLUSIONS: In swimmers not chronically exposed to high chlorine concentrations, data obtained at baseline suggest a direct relationship between airway neutrophilia and endurance training. The low L-selectin expression by airway cells postexercise suggests hyperventilation-induced cell recruitment or modulation of cell function. Hypertonic exposure of airways during exercise may slightly increase airway eosinophils and exhaled NO. Overall, 5-km swimming exerted smaller effects on airway cells than running a marathon.     

Lumbar intervertebral disk degeneration in elite competitive swimmers: a case control study

BACKGROUND: The majority of orthopaedic problems experienced by competitive swimmers are related to pain in the shoulder, low back, and knee. Three of 39 national swim team members were hampered in their performance due to lumbar disk herniation at an international competition in 2001. There has been no previous research into lumbar disk degeneration in elite competitive swimmers. HYPOTHESIS: Excessive competitive swimming activities accelerate lumbar disk degeneration. STUDY DESIGN: Case control study; Level of evidence, 3. METHODS: Fifty-six elite swimmers (high-load group, 35 men and 21 women; mean age, 19.6 years) and a control group of 38 university recreational level swimmers (low-load group, 24 men and 14 women; mean age, 21.1 years) were evaluated for lumbar disk degeneration using magnetic resonance imaging. We compared the prevalence of disk degeneration and the disk level between the 2 groups and further investigated the relationship among their symptoms, swimming styles, and disk degeneration. RESULTS: Thirty-eight (68%) elite swimmers and 11 (29%) controls had degenerated disks at various disk levels, and the prevalence was significantly greater in the elite swimmers (P = .0002). Comparison between the 2 groups of the prevalence of disk degeneration at each level revealed that the disk level of L5-S1 was significantly more frequently degenerated in the high-load group (P = .026). There was no significant relationship observed among the variables of low back pain symptoms, swimming strokes, and disk degeneration. CONCLUSION: Excessive competitive swimming activities might exaggerate lumbar intervertebral disk degeneration, especially in the L5-S1 intervertebral segment.     

Comparison of lung volume in Greek swimmers, land based athletes, and sedentary controls using allometric scaling.

OBJECTIVE: To compare lung volumes in a large cross sectional sample of Greek swimmers, land based athletes, and sedentary controls by means of allometric scaling. METHODS: Four hundred and fifty nine asymptomatic Greek children and young adults (age 10-21 years), including 159 swimmers, 130 land based athletes, and 170 sedentary controls, performed forced expiratory manoeuvres into a portable spirometer. Measurements included forced vital capacity, forced expiratory volume in one second (FEV1.0), and peak expiratory flow. Body mass and stature were also measured using standardised anthropometric techniques. RESULTS: Logarithmic transformations showed that in FEV1.0 was highly related to in stature in males and females (r = 0.93 and 0.86 respectively, P < 0.001) and were used to determine the exponent in an allometric equation which also included age and age. Resulting power functions, FEV1.0/stature, were 0.64 (0.18) litres/m2.69 and 0.33 (0.24) litres/m2.32 for males and females respectively (mean (SE)). The male and female swimming groups had larger FEV1.0 than both land based athletes and sedentary controls (one way analysis of variance, P < 0.001). In addition, male national standard swimmers (n = 38) had superior FEV1.0 in comparison with male non-national standard swimmers (n = 24; t test, P < 0.05). However, when years of swimming training was controlled for by analysis of covariance, the difference in FEV1.0 between the two groups was no longer evident. CONCLUSIONS: Swimmers have superior FEV1.0 independent of stature and age in comparison with both land based athletes and sedentary controls. In addition, male national standard swimmers have superior FEV1.0 independent of stature and age in comparison with male non-national standard swimmers. When years of training is controlled for, the difference in FEV1.0 between the two groups is no longer evident. This suggests that the years of swimming training and/or the earlier age at which training begins may have a significant influence on subsequent FEV1.0 and swimming performance. However, because of the cross sectional nature of this study, the results do not exclude genetic endowment as a major determinant of the superior lung volume observed in swimmers.     

Hip velocity and arm coordination in front crawl swimming

The hip intracyclic velocity variability and the index of coordination in front crawl swimming were examined in relation to performance level. 22 swimmers were assigned to either an elite or a recreational swimming group and performed 4 swim trials at different paces relative to their individual maximum velocity. A velocity meter system was set to determine intracyclic velocity variability and video analysis allowed the determination of the index of coordination. Mean intracyclic velocity variability was lower in the elite swimmers than the recreational swimmers (14.39 ± 1.97 vs. 17.80 ± 4.23%, p<0.05), and remained stable with swim pace (i. e., the relative velocity) for the elite group, whereas it increased for the recreational group (p<0.05). The elite swimmers were characterized by a lower mean index of coordination than the recreational swimmers (-9.6 ± 7.1 vs. -6.9 ± 5.0%, p<0.05), but it increased with swim velocity in the elite group and showed only a tendency in the recreational group (p=0.07). These findings suggest that low intracyclic velocity variability and its stability over a range of swimming paces, which result from optimized inter-arm coordination, are characteristic of skilled performance. Thus, the examination of intracyclic velocity variability and index of coordination variability with different swim paces could provide new insight into skilled performance in swimming.     

Glucose response after a ten-week training in swimming

The present study investigated the difference in blood glucose concentration (Glu) response during an incremental swimming test before and after a ten-week training period and verified whether blood glucose threshold (GT) could be determined in competitive swimmers. 7 elite male university swimmers participated in this study. 2 incremental swimming tests were conducted in a swimming flume before and after a ten-week training period. Blood lactate concentration (Bla) and Glu were measured after each swimming step, and the velocities of the lactate threshold (VLT) and glucose threshold (VGT) were analyzed. VLT increased significantly after training (1.21±0.06 m x s(-1) pre-training, 1.31±0.10 m x s(-1) post-training, p<0.05), while Glu did not increase at the higher swimming intensity steps. GT was not determined at each trial. Our results show that lactate threshold (LT) improved significantly after the ten-week training period, while the Glu response during incremental swimming tests did not change. Therefore, GT could not be determined in elite competitive swimmers before and after training.     

Illness and absence among wrestlers, swimmers, and gymnasts at a large university

The object of this study was to document the prevalence of illness and absence in members of three men's intercollegiate athletic teams: varsity wrestling, swimming, and gymnastics. Team members (N = 87) were interviewed weekly in January and February during 8 weeks of their competitive season. Symptoms, signs, and their duration were recorded on a standard form, as well as the number of days of absence from at least one class or team practice or competition. Mean prevalence of illness was 54 per 100 persons during the first 5 weeks of the study and 30 per 100 persons during the last 3 weeks. Eight-six percent of the athletes had at least one respiratory illness during the 8 week period and 40% reported skin problems. There were no significant differences among teams for respiratory or skin problems. Gastrointestinal symptoms were significantly more frequent among swimmers than among wrestlers or gymnasts (chi 2 = 16.1, df = 2, P less than 0.001). During an illness, an athlete was less likely to miss class than practice or competition (chi 2 = 5.33, df = 1, P less than 0.05). We conclude that there were no significant differences in the prevalence of illness among the three teams except that swimmers had more gastrointestinal problems as well as a transient syndrome associated with abnormal water quality (pH) in the swimming pool.     

Short-term changes in the immune system of elite swimmers under competition conditions: Different immunomodulation induced by various types of sport

This study was designed to investigate changes in the immune system of elite swimmers compared with well-conditioned age- and sex-matched controls in relation to a competition swim (field study). Furthermore, the aim was to reveal possible differences in immune system changes depending on the type of sport performed by comparing with an earlier study of similar design, from the same laboratory that tested elite runners in relation to a competition run. The swimmers were tested before, immediately after and 2 h and 24 h after a competition swim. Lymphocyte subsets (CD5, CD3, HLA-DR, CD4, CD8, CD19, CD3/CD16+56, CD57, CD18, CD16/CD122) all increased after the run, decreased to normal or subnormal levels after 2h, and returned to normal after 24 h (absolute numbers). The findings were identical for the swimmers and the age- and sex-matched control group. No change in polymorphonuclear granulocyte migration was found. The lymphocyte proliferative responses decreased 2 h after the exercise. No changes were seen in plasma cytokine levels (interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α) in relation to exercise, but significantly lower baseline values for IL-6 were observed in the swimmers. An increase in total natural killer cell activity immediately after exercise, followed after 2 h by a decrease, was seen in both swimmers and controls. Finally, no complement activation was detected. Compared with an earlier study of elite runners, differences were seen in granulocyte chemotactic response, TNF-α plasma activity and the lymphocyte proliferative response to mitogen. These differences might be explained by the degree of immune system activation following muscle damage during exercise, inducing an increase in cytokines, which are known to activate and modulate both lymphocytes and granulocyte function. Our findings demonstrate identical exercise-induced, immune system changes in elite swimmers and well conditioned controls, and furthermore, the findings suggest that different types of sport performed at maximum intensity induce different immune system changes.     

Bronchoconstriction during cross-country skiing: is there really a refractory period?

PURPOSE: The asthmatic airway responds to exercise by bronchodilation (BD) during and bronchoconstriction (BC) after exercise. A refractory period induced by an initial exercise challenge that provides protection against BC during a subsequent exercise bout has also been observed. However, no studies examining during-exercise response or refractoriness during long-duration field exercise by elite athletes have been performed. This study examined airway response and refractoriness during approximately 42-min cross-country ski time trial preceded by a 6- to 9-min 2.5-km high-intensity warm-up ski. METHODS: Eighteen elite athletes cross-country skied seven successive 2.5-km loops. Spirometry was performed pre- and at 5, 10, and 15 min post loop 1; loops 2-7 were treated as a race (XCR) with maneuvers performed within 20 s after loops 2-6 and serially for 15 min after lap 7. RESULTS: Nine of 18 subjects demonstrated a >or=10% fall from baseline in FEV(1) (EIB+): five after lap 1 and four during or after laps 2-7. FEV(1) for EIB+ athletes during XCR was not different from post lap 1 FEV. Only one EIB+ subject demonstrated significant refractoriness. Four EIB+ athletes had a less than 10% fall in FEV after the initial 2.5-km exercise challenge but developed EIB (>or=10% fall) during the subsequent 6 x 2.5 km XCR exercise challenge. FEF(25-75) falls mirrored FEV(1), but demonstrated greater BD during XCR. CONCLUSION: Bronchoconstriction occurs in athletes during prolonged exercise and may thus influence performance. Variability in bronchial hyperresponsiveness onset and the lack of significant refractoriness in our study cohort of athletes is consistent with an exercise bronchoconstrictive dysfunction that is different than frank asthma and is yet to be clearly defined.     

Physiological responses of triathletes to maximal swimming, cycling, and running

The objectives of this study were to: (a) develop a physiological profile for a group of trained triathletes and (b) determine whether multiple modes of training result in general or specific adaptations. VO2max of 13 trained triathletes (mean = 29.5 yr) was measured during treadmill running (TR), cycle ergometry (CE), and tethered swimming (TS) over a 6-wk period encompassing a half-triathlon (1.2 mile swim/56 mile bike/13.1 mile run). Most subjects performed two tests in each mode. Since test-retest reliability coefficients for TR, CE, and TS VO2max were 0.97, 0.93, and 0.97, respectively, results were averaged: formula; see text The mean TR VO2max indicated that the subjects were well-trained, but not of elite caliber. Mean CE VO2max was 95.7% of the TR value, which is greater than the value typically found in non-cyclists (88 to 92%) but less than that of highly trained cyclists (98 to 105%). Mean TS VO2max was 86.6% of the TR value. As in cyclists, this percentage is greater than that of recreational swimmers (78 to 82%) but less than that of elite swimmers (93 to 95%). Running and cycling times in the triathlon were significantly (P less than 0.01) related to the corresponding VO2max values (r = -0.68 and r = -0.78, respectively), but swimming times were not (r = -0.50). It is concluded that these triathletes were well-trained in all events, but not to the same extent as athletes who train in only one sport. Running and cycling performance were associated with VO2max.(ABSTRACT TRUNCATED AT 250 WORDS)