An overview of asthma and airway hyper-responsiveness in Olympic athletes

Data from the past five Olympic Games obtained from athletes seeking to inhale β2 adrenoceptor agonists (IBA) have identified those athletes with documented asthma and airway hyper-responsiveness (AHR). With a prevalence of about 8%, asthma/AHR is the commonest chronic medical condition experienced by Olympic athletes. In Summer and Winter athletes, there is a marked preponderance of asthma/AHR in endurance-trained athletes. The relatively late onset of asthma/AHR in many older athletes is suggestive that years of endurance training may be a contributory cause. Inspiring polluted or cold air is considered a significant aetiological factor in some but not all sports. During the last five Olympic Games, there has been improved management of athletes with asthma/AHR with a much higher proportion of athletes combining inhaled corticosteroids (ICS) with IBA and few using long-acting IBA as monotherapy. Athletes with asthma/AHR have consistently outperformed their peers, which research suggests is not due to their treatment enhancing sports performance. Research is necessary to determine how many athletes will continue to experience asthma/AHR in the years after they cease intensive endurance training.     

Exercise-induced asthma screening of elite athletes: field versus laboratory exercise challenge

PURPOSE: The purpose of this study was to compare a laboratory based exercise challenge (LBC) to a field based exercise challenge (FBC) for pulmonary function test (PFT) exercise-induced asthma (EIA) screening of elite athletes. METHODS: Twenty-three elite cold weather athletes (14 men, 9 women) PFT positive for EIA (FBC screened) served as subjects. Twenty-three gender and sport matched controls (nonasthmatics) were randomly selected to establish PFT reference values for normal elite athletes. Before FBC, athletes completed a medical history questionnaire for EIA symptoms. FBC evaluations consisted of baseline spirometry, actual or simulated competition, and 5, 10, and 15 min postexercise spirometry. PFT positive athletes were evaluated in the laboratory using an exercise challenge simulating race intensity (ambient conditions: 21 degrees C, 60% relative humidity). PFT procedures were identical to FBC. RESULTS: 91% of PFT positive and 48% of PFT normal athletes reported at least one symptom of EIA, with postrace cough most frequent. Baseline spirometry was the same for PFT positives and normal controls. Lower limit reference range (MN - 2 SD) of FEV1 for controls suggests that postexercise decrements of greater than approximately -7% indicate abnormal airway response in this population. Exercise time duration did not effect bronchial reactivity; 78% of FBC PFT positives were PFT normal post-LBC. CONCLUSION: Self-reported symptoms by elite athletes are not reliable in identifying EIA. Reference range criterion for FEV1 decrement in the elite athlete postexercise contrasts current recommended guidelines. Moreover, a large number of false negatives may occur in this population if EIA screening is performed with inadequate exercise and environmental stress.     

Screening elite winter athletes for exercise induced asthma: a comparison of three challenge methods

Background

The reported prevalence of exercise induced asthma (EIA) in elite winter athletes ranges from 9% to 50%. Many elite winter athletes do not report symptoms of EIA. At present there is no gold standard test for EIA.

Objective

To establish the efficacy of screening for EIA and examine the role of the eucapnic voluntary hyperventilation (EVH) challenge and laboratory based and sport specific exercise challenges in the evaluation of elite winter athletes.

Methods

14 athletes (mean (SD) age 22.6 (5.7) years, height 177.2 (7.0) cm, body mass 68.9 (16.9) kg) from the Great Britain short‐track speed skating (n = 10) and biathlon teams (n = 4) were studied. Each athlete completed a laboratory based and sport specific exercise challenge as well as an EVH challenge, in randomised order.

Results

All 14 athletes completed each challenge. Two had a previous history of asthma. Ten (including the two with a previous history) had a positive test to at least one of the challenges. Ten athletes had a positive response to EVH; of these, only three also had a positive response to the sport specific challenge. No athletes had a positive response to the laboratory based challenge.

Conclusions

Elite athletes should be screened for EIA. EVH is a more sensitive challenge in asymptomatic athletes than sport specific and laboratory based challenges. If sporting governing bodies were to implement screening programmes to test athletes for EIA, EVH is the challenge of choice.     

American College of Sports Medicine position stand: prevention of cold injuries during exercise

It is the position of the American College of Sports Medicine that exercise can be performed safely in most cold-weather environments without incurring cold-weather injuries. The key to prevention is use of a comprehensive risk management strategy that: a) identifies/assesses the cold hazard; b) identifies/assesses contributing factors for cold-weather injuries; c) develops controls to mitigate cold stress/strain; d) implements controls into formal plans; and e) utilizes administrative oversight to ensure controls are enforced or modified. The American College of Sports Medicine recommends that: 1) coaches/athletes/medical personnel know the signs/symptoms and risk factors for hypothermia, frostbite, and non-freezing cold injuries, identify individuals susceptible to cold injuries, and have the latest up-to-date information about current and future weather conditions before conducting training sessions or competitions; 2) cold-weather clothing be chosen based on each individual's requirements and that standardized clothing ensembles not be mandated for entire groups; 3) the wind-chill temperature index be used to estimate the relative risk of frostbite and that heightened surveillance of exercisers be used at wind-chill temperatures below -27 degrees C (-18 degrees F); and 4) individuals with asthma and cardiovascular disease can exercise in cold environments, but should be monitored closely.     

东北寒区作训官兵支气管哮喘流行病学调查分析

目的 了解东北寒区作训官兵支气管哮喘的发病率和相关危险因素,探讨支气管哮喘的防护策略.方法 选择2012年沈阳军区部分入伍新兵作为研究对象,对2012年度新兵共进行三轮问卷调查,对疑诊哮喘的官兵行肺功能检查进行确诊.第一轮调查在新兵入伍集训时进行,第二轮调查在入选新兵入伍2年的冬训后进行,第三轮调查在入选士兵退伍前进行.结果 在第一轮调查中,新入伍官兵的哮喘患病率为3.55‰,第二轮发现可疑患病人员1067人,第三轮确诊26人,发病率为1.73‰.哮喘官兵首次发作症状最常见的是咳嗽(88.5％)和喘息(56.3％).哮喘官兵发作诱因主要是呼吸道感染(76.9％)和接触冷空气(65.4％),哮喘好发时间为凌晨(30.8％)和清晨(23.1％).26例哮喘患者中有19例(73.1％)发生在冬季,10例(38.5％)发生在春季,呈现出明显的季节特征.劳累、个人过敏史、接触冷空气、慢性支气管炎、吸烟、训练中吸入弹药气味和情绪不良等均能增加哮喘的发病率.结论 劳累对官兵哮喘发病率的影响最大,个人过敏史、接触冷空气、慢性支气管炎、吸烟、吸入弹药气味、情绪等是诱发哮喘的危险因素.     

Zinc status in athletes: relation to diet and exercise

Zinc is involved in the biochemical processes supporting life, such as cellular respiration, DNA reproduction, maintenance of cell membrane integrity and free radical scavenging. Zinc is required for the activity of more than 300 enzymes, covering all 6 classes of enzyme activity. Zinc binding sites in proteins are often of distorted tetrahedral or trigonal bipyramidal geometry, made up of the sulphur of cysteine, the nitrogen of histidine or the oxygen of aspartate and glutamate, or a combination. Zinc in proteins can either participate directly in chemical catalysis or be important for maintaining protein structure and stability. The nutritional habits of elite athletes during training and competition are quite different from the recommended diet in the majority of the population. Endurance athletes often adopt an unusual diet in an attempt to enhance performance: an excessive increase in carbohydrates and low intake of proteins and fat may lead to suboptimal zinc intake in 90% of athletes. Mild zinc deficiency is difficult to detect because of the lack of definitive indicators of zinc status. In athletes, zinc deficiency can lead to anorexia, significant loss in bodyweight, latent fatigue with decreased endurance and a risk of osteoporosis.     

Renal responses to bicycle exercise in trained athletes: influence of exercise intensity

The effects of exercise on renal function were studied in 11 male bicyclists, using a bicycle ergometer. At a work intensity of 100/150 W, bicycle exercise for 1 h was associated with a significant increase in urine volume, endogenous creatinine clearance, and renal sodium and potassium excretion. In contrast, exercise of the same duration at a work intensity of 150/200 W produced no significant changes in the above variables. Exercise intensity seems to influence renal responses, presumably through a differential effect on renal blood flow.     

The isokinetic rotator cuff strength ratios in overhead athletes: Assessment and exercise effect

ObjectiveMuscle strength imbalance in the shoulder region can be considered as a predisposing factor in the development of movement dysfunctions, possibly leading to overuse injuries. Repetitive overhead throwing, performed in sports, may result in muscle imbalance between the external (ER) and internal (IR) rotators. Muscle strength measured with an isokinetic device, is reported as a concentric (CON) or eccentric (ECC) force. The balance between an agonist and an antagonist is mentioned as a ratio (CON/CON or ECC/CON). The aim of this systematic literature review is to provide an overview of the existing evidence considering the isokinetic muscle strength ratios of ER and IR of the shoulder in healthy overhead athletes. In addition, the effect of exercise programs on these ratios was investigated.MethodsTwo online databases (Web of Science and PubMed) were consulted using different search strategies. Articles were selected based on inclusion and exclusion criteria. All included articles were assessed on their methodological quality.Results and conclusionsThere is moderate evidence for a lower functional deceleration ratio (ECC ER/CON IR) at the dominant side. This lower ratio is due to a large overweight of CON IR strength on that side. There is no consensus about which exercise program is the most effective in altering the shoulder isokinetic strength ratios.     

The impact of patellar tendinopathy on sports and work performance in active athletes

Greater insight into sports and work performance of athletes with patellar tendinopathy (PT) will help establish the severity of this common overuse injury. Primary aim of this study is to investigate the impact of PT on sports and work performance. Seventy seven active athletes with PT (50 males; age 28.1 ± 8.2 years; Victorian Institute of Sports Assessment Patella 56.4 ± 12.3) participated in this survey. Sports performance, work ability and work productivity were assessed using the Oslo Sports Trauma Research Center overuse injury questionnaire, the single-item Work Ability Index and the Quantity and Quality questionnaire, respectively. Reduced sports performance was reported by 55% of the participants; 16% reported reduced work ability and 36% decreased work productivity, with 23% and 58%, respectively, for physically demanding work. This study shows that the impact of PT on sports and work performance is substantial and stresses the importance of developing preventive measures.     

The diagnostic accuracy of exercise electrocardiography in asymptomatic recreational and competitive athletes

The goals of this study were to determine the prevalence and determinants of false‐positive exercise tests in athletes. Data from all athletes who visited the Department of Sport Medicine for assessment of sports eligibility during a 1.5‐year period were reviewed retrospectively. Potential determinants of (false) positive test results that were evaluated included demographics, cardiovascular risk factors, sports characteristics, resting electrocardiogram (ECG) abnormalities, and exercise capacity. Data from 1298 athletes were included. In 53 athletes (4.1%), the exercise ECG was classified as positive. Among 38 athletes who were referred to a sports cardiologist for further diagnostic evaluation, 36 (95%) were classified as having a false‐positive test result and 2 athletes (5%) required coronary revascularization. Athletes with a false‐positive test were older than athletes with a negative test (53 ± 8 vs 45 ± 13 years, P = 0.03). In conclusion, exercise electrocardiography has a low positive predictive value in asymptomatic recreational and competitive athletes, with a false‐positive test result being associated with higher age. Given the relatively high prevalence of false‐positive test results in this population, efforts should be made to develop strategies aimed at identifying false‐positive test results in a simple noninvasive manner.     

Iron deficiency in female athletes: its prevalence and impact on performance

The prevalence of iron deficiency and its impact on performance have not been adequately investigated in non-endurance athletes. This study evaluated these factors in 100 female intercollegiate athletes in various sports, and in 66 non-athletes. All subjects had determinations of hemoglobin, ferritin, and transferrin saturation. Athletes reported on diet, menses, and symptoms. Athletes and coaches described mood and performance. Iron-deficient athletes were treated with iron; others received placebo. The same data were collected at season's end. Initially 31/100 (31%) athletes had iron deficiency (ferritin less than 12 ng.ml-1; transferrin saturation less than 16%, or both) compared to 30/66 (45.5%) controls (not statistically significant). Compared to normal athletes, iron-deficient athletes did not have more symptoms of iron deficiency or differences in mood state, but they considered their performance to be worse (P less than 0.05). Their total iron intakes were similar, as were menstrual blood losses. At re-evaluation, 7/45 (15.6%) initially normal athletes were iron-deficient; 14/22 (63.6%) initially iron-deficient athletes were normal. Athletes receiving an iron supplement and their coaches did not report a greater improvement in performance or mood than athletes receiving a placebo. Female college athletes frequently had iron deficiency that could be successfully treated during the season, while some untreated normal athletes became iron-deficient. Iron deficiency and its treatment had no significant impact on symptoms or mood, but affected subjective assessment of performance.     

Prevalence of asthma and atopy in Italian Olympic athletes

This study aimed to assess the prevalence of asthma and atopy in the Italian athletes who were trying for a position on the Italian Olympic team for the 2000 Sydney Olympic Games. Overall, 1060 athletes (mean age 24 years, range 15 - 69 years, 729 males) were recruited and divided into three groups of sport activities: 1) anaerobic, 2) aerobic-anaerobic, 3) aerobic. Asthmatic and atopic athletes were identified by a self-administered, standardized questionnaire modified from the ISAAC questionnaire. Spirometry was performed in the athletes who reported wheezing or asthma and in an equal number of randomly selected controls. Athletes reporting wheezing or asthma were 15 %. However, only a minority of asthmatics had moderate or severe disease: indeed, 2.5 % reported more than 4 attacks in the last year. The prevalence of atopy was 18 %. Asthma was more common in athletes engaged in aerobic sport activities than in the other groups. Asthmatic athletes had a significantly lower value of some spirometric parameters in comparison with the control group. In conclusion, the prevalence of wheezing or asthma in a large sample of Italian competitive athletes was found higher than in general population; respiratory symptoms were more prevalent in athletes engaged in aerobic sport activities; a significant impairment of lung function was found in athletes suffering from mild and rarely symptomatic asthma.     

The impact of sport related stressors on immunity and illness risk in team-sport athletes

Objectives

Elite team-sport athletes are frequently exposed to stressors that have the potential to depress immunity and increase infection risk. Therefore, the purpose of this review is to describe how team-sport stressors impact upon immune responses, along with exploring whether alterations in these markers have the potential to predict upper respiratory tract illness symptoms.

Autonomic recovery after exercise in trained athletes: intensity and duration effects

PURPOSE: To investigate the effects of training intensity and duration, through a range representative of training in endurance athletes, on acute recovery of autonomic nervous system (ANS) balance after exercise. METHODS: Nine highly trained (HT) male runners (VO2max 72 +/- 5 mL.kg.min(-1), 14 +/- 3 training hours per week) and eight trained (T) male subjects (VO2max 60 +/- 5 mL.kg.min(-1), 7 +/- 1 training hours per week) completed preliminary testing to determine ventilatory thresholds (VT1, VT2) and VO2max. HT performed four intensity-controlled training sessions: 60 min and 120 min below VT1; 60 min with 30 min between VT1 and VT2 (threshold); and 60 min above VT2 (6 x 3 min at 96% VO2max, 2 min of recovery). T also completed the interval session to compare ANS recovery between HT and T. Supine heart rate variability (HRV) was quantified at regular intervals through 4 h of recovery. RESULTS: When HT ran 60 or 120 min below VT1, HRV returned to pretraining values within 5-10 min. However, training at threshold (2.7 +/- 0.4 mM) or above VT2 (7.1 +/- 0.7 mM) induced a significant, but essentially identical, delay of HRV recovery (return to baseline by approximately 30 min). In T, HRV recovery was significantly slower, with HRV returning to baseline by >or=90 min after the same interval session. CONCLUSIONS: In the highly trained endurance athlete, exercise for 相似文献