Oil supplementation with a special combination of n-3 and n-6 long-chain polyunsaturated fatty acids does not protect for exercise induced asthma: a double-blind placebo-controlled trial.

BACKGROUND: Many patients suffering from exercise-induced asthma (EIA) have normal lung function at rest and show symptoms and a decline in FEV1 when they do sports or during exercise-challenge. It has been described that long-chain polyunsaturated fatty acids (LCPUFA) could exert a protective effect on EIA. METHODS: In this study the protective effect of supplementation with a special combination of n-3 and n-6 LCPUFA (sc-LCPUFA) (total 1.19 g/ day) were investigated in an EIA cold air provocation model. PRIMARY OUTCOME MEASURE: Decrease in FEV1 after exercise challenge and secondary outcome measure: anti-inflammatory effects monitored by exhaled NO (eNO) before and after sc-LCPUFA supplementation versus placebo. RESULTS: Ninety-nine patients with exercise-induced symptoms aged 10 to 45 were screened by a standardized exercise challenge in a cold air chamber at 4 °C. Seventy-three patients fulfilled the inclusion criteria of a FEV1 decrease > 15% and were treated double-blind placebo-controlled for 4 weeks either with sc-LCPUFA or placebo. Thirty-two patients in each group completed the study. Mean FEV1 decrease after cold air exercise challenge and eNO were unchanged after 4 weeks sc-LCPUFA supplementation. CONCLUSION: Supplementation with sc-LCPUFA at a dose of 1.19 g/d did not have any broncho-protective and anti-inflammatory effects on EIA. TRIAL REGISTRATION: Clinical trial registration number: NCT02410096. Registered 7 February 2015 at Clinicaltrial.gov.

Exercise and Asthma.

Transient airway narrowing can occur during or following exercise, a phenomenon called exercise-induced bronchoconstriction (EIB). The main mechanism of EIB is considered to be airway dehydration, resulting from increased ventilation during exercise. In asthma, such water loss causes an increase in airway fluid osmolarity, inducing airway smooth muscle contraction following the release of mediators from airway inflammatory cells. Asthmatics frequently experience EIB, but it may also be observed in others not reporting asthma symptoms, particularly elite endurance athletes. Individuals with asthma often refrain from performing physical exercise because they fear troublesome respiratory symptoms. However, in addition to its well-known cardiovascular and metabolic benefits, physical training has been shown to be beneficial for asthmatic adults and children in improving asthma control and asthma-related quality of life. Exercise training also reduces the risk of asthma exacerbations, improves exercise capacity, and decreases frequency and severity of EIB. To minimize the risk of EIB, asthma must be well controlled, and specific pharmacological and nonpharmacological preventative measures can be taken. Counterintuitively, in high-level athletes, the development of asthma, airway hyperresponsiveness, and EIB can be promoted by intense training over many years following exposure to environmental conditions, such as cold air, pollutants, and allergens. As for nonathletes, athletes must have optimal asthma control and apply preventative measures against EIB, taking into account antidoping regulations for asthma medications. A better understanding of the impact of exercise on asthma should improve the overall care of asthmatic patients.

Wheat Allergy and Intolerence; Recent Updates and Perspectives.

The current review paper highlights the complicacies associated with communities relying on wheat as their dietary staple. Although, wheat is an important source of nutrients but is also linked with allergenic responses in genetically susceptible subjects. The wheat proteins especially α-amylase inhibitors, ω-5 gliadins, prolamins, nonprolamin, glucoprotein, and profilins are of significance importance. The allergenic responses are further categorized into IgE-mediated and non-IgE-mediated reactions. Conjugation and degranulation of the IgEs with the allergens results in release of several mediators. In contrary, non-IgE-mediated wheat allergy depends on immune complexes formed by food and food antibodies and cell-mediated immunity. As results, different diseases tend to occur on the completion of these reactions, i.e., celiac disease, baker's asthma, diarrhea, atopic dermatitis, and urticaria. This instant paper highlighted the concept of food allergy with special reference to wheat. The models are developed that are included in this paper showing the wheat allergen, their possible routes, impact on human health, and indeed possible remedies. The paper would provide the basic information for the researchers, common man, and allied stakeholders to cater the issue in details. However, the issue needs the attention of the researchers as there is a need to clarify the issues of wheat allergy and wheat intolerance.

Combination of budesonide/formoterol on demand improves asthma control by reducing exercise-induced bronchoconstriction.

BACKGROUND: In mild asthma exercise-induced bronchoconstriction (EIB) is usually treated with inhaled short-acting ß2 agonists (SABAs) on demand. OBJECTIVE: The hypothesis was that a combination of budesonide and formoterol on demand diminishes EIB equally to regular inhalation of budesonide and is more effective than terbutaline inhaled on demand. METHODS: Sixty-six patients with asthma (>12 years of age) with verified EIB were randomised to terbutaline (0.5 mg) on demand, regular budesonide (400 µg) and terbutaline (0.5 mg) on demand, or a combination of budesonide (200 µg) + formoterol (6 µg) on demand in a 6-week, double-blind, parallel-group study (ClinicalTrials.gov identifier: NCT00989833). The patients were instructed to perform three to four working sessions per week. The main outcome was EIB 24 h after the last dosing of study medication. RESULTS: After 6 weeks of treatment with regular budesonide or budesonide+formoterol on demand the maximum post-exercise forced expiratory volume in 1 s fall, 24 h after the last medication, was 6.6% (mean; 95% CI -10.3 to -3.0) and 5.4% (-8.9 to -1.8) smaller, respectively. This effect was superior to inhalation of terbutaline on demand (+1.5%; -2.1 to +5.1). The total budesonide dose was approximately 2.5 times lower in the budesonide+formoterol group than in the regular budesonide group. The need for extra medication was similar in the three groups. CONCLUSIONS: The combination of budesonide and formoterol on demand improves asthma control by reducing EIB in the same order of magnitude as regular budesonide treatment despite a substantially lower total steroid dose. Both these treatments were superior to terbutaline on demand, which did not alter the bronchial response to exercise. The results question the recommendation of prescribing SABAs as the only treatment for EIB in mild asthma.

An official American Thoracic Society clinical practice guideline: exercise-induced bronchoconstriction.

BACKGROUND: Exercise-induced bronchoconstriction (EIB) describes acute airway narrowing that occurs as a result of exercise. EIB occurs in a substantial proportion of patients with asthma, but may also occur in individuals without known asthma. METHODS: To provide clinicians with practical guidance, a multidisciplinary panel of stakeholders was convened to review the pathogenesis of EIB and to develop evidence-based guidelines for the diagnosis and treatment of EIB. The evidence was appraised and recommendations were formulated using the Grading of Recommendations, Assessment, Development, and Evaluation approach. RESULTS: Recommendations for the treatment of EIB were developed. The quality of evidence supporting the recommendations was variable, ranging from low to high. A strong recommendation was made for using a short-acting ß(2)-agonist before exercise in all patients with EIB. For patients who continue to have symptoms of EIB despite the administration of a short-acting ß(2)-agonist before exercise, strong recommendations were made for a daily inhaled corticosteroid, a daily leukotriene receptor antagonist, or a mast cell stabilizing agent before exercise. CONCLUSIONS: The recommendations in this Guideline reflect the currently available evidence. New clinical research data will necessitate a revision and update in the future.

Mothers impose physical activity restrictions on their asthmatic children and adolescents: an analytical cross-sectional study.

BACKGROUND: Physical activities are important for children and adolescents, especially asthmatics. A significant proportion is considered less active than their non-asthmatic peers and mother's beliefs about asthma are thought to be a determinant factor.The research objectives were to investigate whether mothers try to impose limitations on the physical activity (PA) of their asthmatic children/adolescents; identify associated factors; and explore if this attitude has any impact on children's PA levels. METHODS: In this cross sectional investigation, we studied 115 asthmatics aged between 9 and 19 years and their mothers. Asthma severity, PA level and exercise induced bronchospasm (EIB) were evaluated. Mothers were questioned on their beliefs about physical activity in non-asthmatic and asthmatic children, if they imposed restrictions on their children's physical activity, on EIB perception and personal levels of anxiety and depression. RESULTS: Ninety six percent of the mothers answered that PA are important for children and adolescents. Despite this, 37% of them admitted imposing restrictions to their children's PA. This attitude was associated with mother's negative opinions about asthmatics doing PA, perception of children's dyspnea after running on a treadmill, mother's anxiety level and children's asthma severity. The mother's restrictive attitudes were not associated with children's lower PA levels. CONCLUSION: A high proportion of the mothers said that they restrained their asthmatic children from engaging in physical activity. This fact should be recognized by health professionals and discussed with parents and caregivers as these negative beliefs may lead to conflicts and prejudiced attitudes that could discourage children's involvement in physical activities and sports.

Is yoga training beneficial for exercise-induced bronchoconstriction?

BACKGROUND: Some studies have shown the beneficial effects of yoga for individuals with bronchial hyperreactivity with regard to (1) a reduction in the use of rescue medication, (2) an increase in exercise capacity, and (3) an improvement in lung function. Despite the fact that yoga is promising as a new treatment for pediatric patients, further studies are needed to assess the use of this training for asthma management. OBJECTIVE: This study was performed to assess the beneficial effects of yoga in exercise-induced bronchoconstriction (EIB) in children. DESIGN: The study was prospective, with no control group. Participants were randomly chosen among the new patients at the unit. SETTING: This study was conducted in the Erciyes University School of Medicine, Pediatric Allergy Unit, in Kayseri, Turkey. PARTICIPANTS: Two groups of asthmatic children aged 6-17 y were enrolled in the study: (1) children with positive responses to an exercise challenge (n = 10), and (2) those with negative responses (n = 10). INTERVENTION: Both groups attended 1-h sessions of yoga training 2 ×/wk for 3 mo. OUTCOME MEASURES: Researchers administered spirometric measurement to all children before and immediately after participating in an exercise challenge. This process was performed at baseline and at the study's end. Age, gender, IgE levels, eosinophil numbers, and spirometric measurement parameters including forced expiratory volume in 1 sec (FEV1), forced expiratory flow 25%-75% (FEF25%-75%), forced vital capacity (FVC), peak expiratory flow percentage (PEF%), and peak expiratory flow rate (PEFR) were compared using the Mann-Whitney U test and the Wilcoxon test. A P value < .05 was considered significant. RESULTS: At baseline, no significant differences were observed between the groups regarding demographics or pre-exercise spirometric measurements (P > .05, Mann-Whitney U test). Likewise, no significant differences in spirometric measurements existed between the groups regarding the change in responses to an exercise challenge after yoga training (P > .05, Wilcoxon test). For the exercise-response-positive group, the research team observed a significant improvement in maximum forced expiratory volume 1% (FEV1%) fall following the exercise challenge after yoga training (P > .05, Wilcoxon test). All exercise-response-positive asthmatics became exerciseresponse-negative asthmatics after yoga training. CONCLUSION: This study showed that training children in the practice of yoga had beneficial effects on EIB. It is the research team's opinion that yoga training can supplement drug therapy to achieve better control of asthma.

[Impact of exercise, sport and rehabilitation therapy in asthma and COPD]. / Impact von Bewegung, Sport und Rehabilitation bei Asthma und COPD.

Patients with chronic obstructive pulmonary disease (COPD) and Asthma share increased physical inactivity as a characteristic and risk factor for the aggravation of their symptoms and marker of their health condition, respectively. Physical inactivity may be objectively measured by means of accelerometry superior to questionnaires. Physical inactivity is the reason for a reduced endurance capacity and a reduction of strength with concomitant decrease of skeletal muscle mass aggravating inflammation as a common pathophysiologic soil. Endurance training is recommended in the form of continuous and interval training having similar effects on endurance capacity executed on either a bike or as walking in patients with COPD und Asthma. Walking inherits the potential additional benefit of a reduction of fall risk which needs additional scientific evidence. This holds true especially for elderly subjects. Strength training is important because of the frequently atrophied skeletal musculature, which triggers the increase of the exercise-induced ventilation by early lactate acidosis and thereby aggravates dyspnea during exercise. An important aspect of therapy is the maintenance of the individualized training after discharge from hospital in the domestic environment taking into consideration training facilities, encounter groups and social circumstances. The objective measurement of physical activity has the potential to guide and control therapy. Because of the frequently present cardio-metabolic comorbidities the assessment of the exercise capacity as well an evaluation of nutrition should be included into a holistic therapeutical approach. An optimized bronchospasmolytic and anti-inflammatory therapy is the basis for a sufficient response to exercise training. In patients with asthma, a warm-up phase of at least 15 min prior to exercise is recommended. Redundant fear of exercise-induced attacks of asthma shall be avoided by doing so. If necessary, additional psychological support should be given.

Common injuries and medical problems in singles figure skaters.

Figure skating continues to increase in popularity as both a recreational and competitive sport. Skaters continue to "push the envelope" in perfecting more technically difficult skills. With their strenuous training programs, skaters are at risk from chronic overuse injuries, which tend to plague singles skaters more often than acute injuries. The majority of injuries occur in the lower extremities or low back. Figure skaters also are at risk for particular medical problems, such as exercise-induced bronchospasm and disordered eating. Sports Medicine physicians are sure to encounter figure skaters and their "Sports-specific problems" in their practice and should be knowledgeable about the common maladies that can plague figure skaters. This article reviews the most common injuries and medical problems in singles figure skaters.

Sports in extreme conditions: the impact of exercise in cold temperatures on asthma and bronchial hyper-responsiveness in athletes.

Exercise-induced asthma (EIA) and bronchial hyper-responsiveness (BHR) are frequently reported among elite athletes of outdoor endurance winter sports, particularly in cross-country and biathlon skiers. The pathogenesis of EIA is related to water loss and heat-loss through the increased respiration during exercise, leading to mediator release, airways inflammation and increased parasympathetic nervous activity in the airways, causing bronchial constriction and BHR. In the competing elite athlete this is presently considered to be due to the frequently repeated increased ventilation during training and competitions in combination with the repeated environmental exposure to cold air in outdoor winter sports. It is important that athletes at risk of asthma and BHR are monitored through regular medical control with assessment of lung function and BHR, and when BHR or asthma is diagnosed, optimal controlling treatment through anti-inflammatory treatment by inhaled steroids should be started and relieving treatment (inhaled ipratropium bromide and inhaled ß2-agonists) should be used to relieve bronchial constriction if present.

Respiratory health of elite athletes - preventing airway injury: a critical review.

Elite athletes, particularly those engaged in endurance sports and those exposed chronically to airborne pollutants/irritants or allergens, are at increased risk for upper and lower airway dysfunction. Airway epithelial injury may be caused by dehydration and physical stress applied to the airways during severe exercise hyperpnoea and/or by inhalation of noxious agents. This is thought to initiate an inflammatory cascade/repair process that, ultimately, could lead to airway hyperresponsiveness (AHR) and asthma in susceptible athletes. The authors review the evidence relating to prevention or reduction of the risk of AHR/asthma development. Appropriate measures should be implemented when athletes exercise strenuously in an attempt to attenuate the dehydration stress and reduce the exposure to noxious airborne agents. Environmental interventions are the most important. Non-pharmacological strategies can assist, but currently, pharmacological measures have not been demonstrated to be effective. Whether early prevention of airway injury in elite athletes can prevent or reduce progression to AHR/asthma remains to be established.

Dietary sodium manipulation and asthma.

BACKGROUND: There is a wide geographical variation in the prevalence of asthma and observational studies have suggested that dietary sodium may play a role. OBJECTIVES: To assess the effect of dietary sodium manipulation on asthma control. SEARCH STRATEGY: We carried out a search using the Cochrane Airways Group asthma register. We searched the bibliographies of included randomised controlled trials (RCTs) for additional studies. We carried out the most recent search in November 2010. SELECTION CRITERIA: We considered only RCTs that involved dietary sodium reduction or increased sodium intake in patients with asthma. DATA COLLECTION AND ANALYSIS: Both review authors assessed study and extracted data. We conducted data analyses in RevMan 5 using mean differences and random effects. MAIN RESULTS: We identified a total of nine studies in relation to sodium manipulation and asthma, of which five were in people with asthma (318 participants), and four in people with exercise-induced asthma (63 participants). There were no significant benefits of salt restriction on the control of asthma. There was some evidence from the exercise-induced asthma studies that a low sodium diet may improve lung function after exercise and possibly baseline lung function, but this is based on findings from a very small numbers of participants. AUTHORS' CONCLUSIONS: This review did not find any evidence that dietary sodium reduction significantly improves asthma control. Although dietary sodium reduction may result in improvements in lung function in exercise-induced asthma, the clinical significance of this effect is unclear.

Asthma in adolescent athletes.

Athletes active in endurance sports are at an increased risk of acquiring asthma through their sports activities, especially so for cross-country skiers, biathlon skiers, swimmers and athletes of other endurance sports. Asthma may be present from early childhood or develop while in active sports. This article focuses on the physical activity and sports activities in children and adolescents. Exercise-induced asthma (EIA) is found in 8-10% of a normal child population of school age and in about 35% of children with current asthma. EIA is caused by the markedly increased ventilation during exercise, with increased heat and water loss through respiration, leading to bronchial constriction. The risk of developing asthma in the young athlete is related to the repeated daily training activity with increased epithelial damage of the airways, delayed repair due to the daily repetition of the training and increased airway mucosal inflammation. The increased environmental exposure through the sports activity to environmental agents, such as cold, dry air in skiers and chlorine compounds in swimmers, increases symptoms and signs of asthma and bronchial hyper-responsiveness, either worsening an existing asthma or leading to a novel disease in a previously healthy athlete. Several specific aspects of daily training life, environmental exposure, diagnostic procedures and aspects of treatment related to the regulations of medication use in sports need particular attention when addressing the adolescent athlete with respiratory symptoms.

Advances in pediatric asthma in 2008: where do we go now?

This year's summary focuses on recent advances in pediatric asthma as reported in Journal publications in 2008. New National Asthma Education and Prevention Program asthma guidelines were released in 2007 with a special emphasis on asthma control. Attention was redirected to methods that could reduce impairment, specifically symptom control, and minimize risk, including exacerbations. Journal theme issues in 2008 focused on several relevant asthma topics including asthma exacerbations, exercise-induced bronchospasm, asthma and obesity, and occupational asthma. This review highlights Journal articles and related articles that reinforce principles of the guidelines and also direct us to new information that will advance asthma care for children. A major step forward will be finding ways to implement the asthma guidelines.

Current concepts in the diagnosis and management of exercise-induced bronchospasm.

Exercise-induced bronchospasm (EIB) is a common occurrence in individuals with asthma, though it can also affect individuals without asthma. It occurs frequently in athletes. Common symptoms include coughing, dyspnea, chest tightness, and wheezing; however, there can be a variety of more subtle symptoms. The differential diagnosis of EIB is broad and includes several pulmonary and cardiac disorders. During the initial evaluation, a complete history, physical examination, and spirometry should be performed. In most patients with EIB, the baseline spirometry is normal; therefore, bronchoprovocation testing is strongly recommended. Both pharmacologic and nonpharmacologic approaches are important in the treatment of EIB. Management of EIB on the sideline of athletic events requires preparation and immediate access to rescue inhalers.

Effect of desloratadine on patients with allergic rhinitis and exercise-induced bronchoconstriction: a placebo controlled study.

BACKGROUND: Exercise induced broncho-constriction (EIB) is a significant problem in asthmatic patients. The link between allergic rhinitis and asthma is now well established. Patients with allergic rhinitis may have EIB. OBJECTIVE: This study compared the effects of desloratadine and placebo on EIB in a group of patients with allergic rhinitis and EIB. METHODS: This was a double blind placebo controlled, randomized, crossover study. Exercise challenge tests were performed before and after 7 days of treatment with either 5 mg desloratadine or placebo. Patients then underwent a washout period for 7 days and were crossed over to receive either 5mg desloratadine or placebo. The exercise challenge tests were repeated. RESULTS: Desloratadine had no effect on the reduction in percentage fall in FEV(1), the AUC (0-60 min) and the time to recovery. CONCLUSIONS: Desloratadine has no effect in attenuating the broncho-constriction caused by exercise in patients with allergic rhinitis and exercise induced broncho-constriction. CLINICAL IMPLICATIONS: Patients with allergic rhinitis and exercise induced broncho-constriction must be treated with either a beta(2)-agonist or LRTA for relief or prophylaxis of their EIB. CAPSULE SUMMARY: Desloratadine does not have an effect on exercise induced bronchoconstriction. Patients with allergic rhinitis with exercise induced bronchoconstriction who are on desloratadine will still require treatment with beta(2) agonist or leukotriene receptor antagonist for their symptoms.

Asthma and the elite athlete: summary of the International Olympic Committee's consensus conference, Lausanne, Switzerland, January 22-24, 2008.

Respiratory symptoms cannot be relied on to make a diagnosis of asthma and/or airways hyperresponsiveness (AHR) in elite athletes. For this reason, the diagnosis should be confirmed with bronchial provocation tests. Asthma management in elite athletes should follow established treatment guidelines (eg, Global Initiative for Asthma) and should include education, an individually tailored treatment plan, minimization of aggravating environmental factors, and appropriate drug therapy that must meet the requirements of the World Anti-Doping Agency. Asthma control can usually be achieved with inhaled corticosteroids and inhaled beta(2)-agonists to minimize exercise-induced bronchoconstriction and to treat intermittent symptoms. The rapid development of tachyphylaxis to beta(2)-agonists after regular daily use poses a dilemma for athletes. Long-term intense endurance training, particularly in unfavorable environmental conditions, appears to be associated with an increased risk of developing asthma and AHR in elite athletes. Globally, the prevalence of asthma, exercise-induced bronchoconstriction, and AHR in Olympic athletes reflects the known prevalence of asthma symptoms in each country. The policy of requiring Olympic athletes to demonstrate the presence of asthma, exercise-induced bronchoconstriction, or AHR to be approved to inhale beta(2)-agonists will continue.

Exercise-induced asthma is associated with impaired quality of life among children with asthma in Japan.

BACKGROUND: Asthma is the most common chronic diseases in school-aged children in Japan. It is important to consider health-related quality of life (QoL) among children with chronic diseases when treatment decisions are made. METHODS: A school-based survey was conducted in randomly selected public schools in Tokyo by using a KINDL questionnaire for evaluating QoL and the international study of asthma and allergy on childhood (ISAAC) questionnaire, which is designed for comparing the asthma prevalence in various countries, from May to June in 2005. We recruited approximately 10% of the total children 6-7-years-old and 13-14-years-old living in Tokyo for sampling. RESULTS: Response rate of this questionnaire was 86% (22,645 children) in the 6-7-year-old group and 64% (12,879 children) in the 13-14-year-old group. Comparing asthmatics with non-asthmatics in the same age, QoL of children with asthma was significantly impaired. The severity of QoL of children with asthma was significantly impaired. QoL of children with exercise-induced asthma (EIA) were more significantly impaired than ones without EIA and showed lower scores in the categories of physical functioning, emotional and school activities than those without EIA. Of note, QoL was more impaired in the EIA-positive group among severe asthmatics, suggesting that QoL of children with even severe asthma could be improved when EIA is appropriately controlled. CONCLUSIONS: Existence of EIA among asthmatic children most strongly impairs their QoL. We should be more cautious about the management of EIA.

Many continuous variables should be analyzed using the relative scale: a case study of ß2-agonists for preventing exercise-induced bronchoconstriction.

BACKGROUND: The relative scale adjusts for baseline variability and therefore may lead to findings that can be generalized more widely. It is routinely used for the analysis of binary outcomes but only rarely for continuous outcomes. Our objective was to compare relative vs absolute scale pooled outcomes using data from a recently published Cochrane systematic review that reported only absolute effects of inhaled ß2-agonists on exercise-induced decline in forced-expiratory volumes in 1 s (FEV1). METHODS: From the Cochrane review, we selected placebo-controlled cross-over studies that reported individual participant data (IPD). Reversal in FEV1 decline after exercise was modeled as a mean uniform percentage point (pp) change (absolute effect) or average percent change (relative effect) using either intercept-only or slope-only, respectively, linear mixed-effect models. We also calculated the pooled relative effect estimates using standard random-effects, inverse-variance-weighting meta-analysis using study-level mean effects. RESULTS: Fourteen studies with 187 participants were identified for the IPD analysis. On the absolute scale, ß2-agonists decreased the exercise-induced FEV1 decline by 28 pp., and on the relative scale, they decreased the FEV1 decline by 90%. The fit of the statistical model was significantly better with the relative 90% estimate compared with the absolute 28 pp. estimate. Furthermore, the median residuals (5.8 vs. 10.8 pp) were substantially smaller in the relative effect model than in the absolute effect model. Using standard study-level meta-analysis of the same 14 studies, ß2-agonists reduced exercise-induced FEV1 decline on the relative scale by a similar amount: 83% or 90%, depending on the method of calculating the relative effect. CONCLUSIONS: Compared with the absolute scale, the relative scale captures more effectively the variation in the effects of ß2-agonists on exercise-induced FEV1-declines. The absolute scale has been used in the analysis of FEV1 changes and may have led to sub-optimal statistical analysis in some cases. The choice between the absolute and relative scale should be determined based on biological reasoning and empirical testing to identify the scale that leads to lower heterogeneity.