Airway inflammation, cough and athlete quality of life in elite female cross-country skiers: A longitudinal study

Immunity, Inflammation and Airway Dysfunction in Elite Cross-Country Skiers and Ice Hockey Players: A Systematic Review

Strenuous exercise in elite sports impacts the immune system, leading to high rates of upper respiratory tract infections and airway dysfunction, such as asthma and exercise-induced bronchoconstriction (EIB). Cross-country (XC) skiers and ice hockey (IH) players are particularly affected due to their training environments and sports disciplines. This systematic review (SR) evaluates immune and inflammatory responses and the risk of developing airway dysfunction in these athletes. Original articles focusing on immune response, systemic inflammation, and airway dysfunction in competitive XC skiers and IH players were retrieved from MEDLINE/Ovid, EMBASE, and the Cochrane Library. Risk of bias was assessed using the Cochrane Risk of Bias Tool. Of 3582 studies screened, 50 met the inclusion criteria. Both elite XC skiers and IH players exhibit increased cortisol levels and altered systemic immune cell compositions in response to training and competition. Both groups show neutrophilic or mixed neutrophilic/eosinophilic airway inflammation, in contrast to the primarily eosinophilic inflammation associated with allergic asthma. Both XC skiers (27%) and IH players (14%) had a high prevalence of physician-diagnosed asthma. This SR highlights the notable burden of airway dysfunction in elite winter athletes, with elevated rates of asthma and EIB. The observed inflammatory patterns support the concept of a "sport asthma" endotype, which may be a result of chronic exposure to cold, dry air. Effective management may benefit from refined diagnostic criteria, the identification of specific biomarkers, and tailored prevention and treatment strategies for asthma and EIB.

Standardised lung function metrics in healthy athletes

The objective of the current review was to identify whether clinically established lung function metrics of ventilatory and diffusion capacity obtained by standardised methodology are consistent with superior lung function in athletes, and whether this is related to maximal oxygen uptake (V̇O2max). Three independent reviewers performed a literature search in PubMed, Scopus, and reference screening. Data was extracted and analysed according to a predefined strategy. Studies published between 1970 and 2023 on athletes reporting V̇O₂max and at least one of the following lung function metrics: predicted forced expiratory volume in the first second of a forced vital capacity manoeuvre (FEV1%pred); predicted forced vital capacity (FVC%pred); predicted total lung capacity (TLC%pred); predicted pulmonary diffusion capacity for carbon monoxide (DL,CO%pred). Data on population size, age, sex, type of sports, as well as FEV1%pred, FVC%pred, TLC%pred, DL,CO%pred, and V̇O2max were extracted. Standardised mean, differences, and 95% CI were calculated when data were sufficient. In total, 13 original studies encompassing 193 individuals across various sports disciplines met the inclusion criteria. Pooled FEV1%pred was 111% (108-113%; 13 studies; n=193), FVC%pred 112% (108-116 %; 7 studies; n=118), TLC%pred 106% (103-108 %; 4 studies; n=60), and DL,CO%pred 121% (120-122 %; 2 studies; n=23). None of the studies provided sufficient data to evaluate the relationship between any of the lung function metrics and V̇O2max. In conclusion, athletes consistently exhibit high ventilatory and diffusing capacity metrics, but it is still unknown whether this is related to V̇O2max.

Elite skiers' experiences of heat- and moisture-exchanging devices and training and competition in the cold: A qualitative survey

Background and Aims

Winter endurance athletes have a high prevalence of exercise-induced bronchoconstriction (EIB) and asthma, probably due to repeated and prolonged inhalation of cold and dry air. Heat- and moisture-exchanging devices (HME) warm and humidify inhaled air and prevent EIB. The aim of this study was to share cross-country skiers and biathletes' experiences of training and competition in low temperatures, views on temperature limits, usage of HME, and consequences of cold exposure on their health.

Methods

Eleven Swedish World Championship or Olympic medalists in cross-country skiing and biathlon were interviewed and transcripts were analyzed using qualitative content analysis.

Results

Participants described how cold temperatures predominantly affected the airways, face, and extremities. During training, extreme cold was managed by choosing warmer clothing, modification of planned sessions, use of HME, delaying training, or changing location. In competition, participants described limited possibility for such choices and would prefer adjustment of existing rules (i.e., more conservative temperature limits), especially since they understood elite skiing in low temperatures to present an occupational hazard to their health. Participants had at times used HMEs during training in cold environments but described mixed motives for their use-that HMEs warm and humidify cold inhaled air but introduce additional resistance to breathing and can cause problems due to mucus and ice build-up. Skiers also perceived that they had become more sensitive to cold during the latter part of their careers.

Conclusions

The present study gives a unique insight into the "cold" reality of being an elite athlete in skiing and biathlon. Cold exposure results in negative health consequences that are preventable, which means that rules must be followed, and organizers should acknowledge responsibility in protecting athletes from occupational hazards. Development of evidence-based guidelines for protection of athletes' respiratory health should be a focus for future translational research.

Effects of physical activity on lung function and quality of life in asthmatic children: An updated systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

The benefits of physical activity (PA) for asthmatic children were increasingly recognized, and as the design of studies on PA and asthma has become more refined in recent years, the latest evidence needed to be updated. We performed this meta-analysis to synthesize the evidence available from the last 10 years to update the effects of PA in asthmatic children.

METHODS

A systematic search was conducted in three databases, PubMed, Web of Science, and Cochrane Library. Randomized controlled trials were included, and two reviewers independently conducted the inclusion screening, data extraction, and bias assessment.

RESULTS

A total of 9 studies were included in this review after 3,919 articles screened. PA significantly improved the forced vital capacity (FVC) (MD 7.62; 95% CI: 3.46 to 11.78; p < 0.001), and forced expiratory flow between 25% and 75% of forced vital capacity (FEF_25-75) (MD 10.39; 95% CI: 2.96 to 17.82; p = 0.006) in lung function. There was no significant difference in forced expiratory volume in the first second (FEV₁) (MD 3.17; 95% CI: -2.82 to 9.15; p = 0.30) and fractional exhaled nitric oxide (FeNO) (MD -1.74; 95% CI: -11.36 to 7.88; p = 0.72). Also, PA significantly improved the quality of life as assessed by the Pediatric Asthma Quality of Life Questionnaire (all items p < 0.05).

CONCLUSIONS

This review suggested that PA could improve FVC, FEF_25-75, and quality of life in asthmatic children, but there was insufficient evidence of improvement in FEV₁ and airway inflammation.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022338984.

Cold air exposure at - 15 °C induces more airway symptoms and epithelial stress during heavy exercise than rest without aggravated airway constriction

PURPOSE

Exposure to cold air may harm the airways. It is unclear to what extent heavy exercise adds to the cold-induced effects on peripheral airways, airway epithelium, and systemic immunity among healthy individuals. We investigated acute effects of heavy exercise in sub-zero temperatures on the healthy airways.

METHODS

Twenty-nine healthy individuals underwent whole body exposures to cold air in an environmental chamber at - 15 °C for 50 min on two occasions; a 35-min exercise protocol consisting of a 5-min warm-up followed by 2 × 15 min of running at 85% of VO2max vs. 50 min at rest. Lung function was measured by impulse oscillometry (IOS) and spirometry before and immediately after exposures. CC16 in plasma and urine, and cytokines in plasma were measured before and 60 min after exposures. Symptoms were surveyed pre-, during and post-trials.

RESULTS

FEV1 decreased after rest (- 0.10 ± 0.03 L, p < 0.001) and after exercise (- 0.06 ± 0.02 L, p = 0.012), with no difference between trials. Exercise in - 15 °C induced greater increases in lung reactance (X5; p = 0.023), plasma CC16 (p < 0.001) as well as plasma IL-8 (p < 0.001), compared to rest. Exercise induced more intense symptoms from the lower airways, whereas rest gave rise to more general symptoms.

CONCLUSION

Heavy exercise during cold air exposure at - 15 °C induced signs of an airway constriction to a similar extent as rest in the same environment. However, biochemical signs of airway epithelial stress, cytokine responses, and symptoms from the lower airways were more pronounced after the exercise trial.

Lymphocyte and dendritic cell response to a period of intensified training in young healthy humans and rodents: A systematic review and meta-analysis

Background: Intensified training coupled with sufficient recovery is required to improve athletic performance. A stress-recovery imbalance can lead to negative states of overtraining. Hormonal alterations associated with intensified training, such as blunted cortisol, may impair the immune response. Cortisol promotes the maturation and migration of dendritic cells which subsequently stimulate the T cell response. However, there are currently no clear reliable biomarkers to highlight the overtraining syndrome. This systematic review and meta-analysis examined the effect of intensified training on immune cells. Outcomes from this could provide insight into whether these markers may be used as an indicator of negative states of overtraining. Methods: SPORTDiscus, PUBMED, Academic Search Complete, Scopus and Web of Science were searched until June 2022. Included articles reported on immune biomarkers relating to lymphocytes, dendritic cells, and cytokines before and after a period of intensified training, in humans and rodents, at rest and in response to exercise. Results: 164 full texts were screened for eligibility. Across 57 eligible studies, 16 immune biomarkers were assessed. 7 were assessed at rest and in response to a bout of exercise, and 9 assessed at rest only. Included lymphocyte markers were CD3⁺, CD4⁺ and CD8⁺ T cell count, NK cell count, NK Cytolytic activity, lymphocyte proliferation and CD4/CD8 ratio. Dendritic cell markers examined were CD80, CD86, and MHC II expression. Cytokines included IL-1β, IL-2, IL-10, TNF-α and IFN-γ. A period of intensified training significantly decreased resting total lymphocyte (d= -0.57, 95% CI -0.30) and CD8⁺ T cell counts (d= -0.37, 95% CI -0.04), and unstimulated plasma IL-1β levels (d= -0.63, 95% CI -0.17). Resting dendritic cell CD86 expression significantly increased (d = 2.18, 95% CI 4.07). All other biomarkers remained unchanged. Conclusion: Although some biomarkers alter after a period of intensified training, definitive immune biomarkers are limited. Specifically, due to low study numbers, further investigation into the dendritic cell response in human models is required.

Influence of exercise duration on respiratory function and systemic immunity among healthy, endurance-trained participants exercising in sub-zero conditions

Background

Strenuous endurance exercise in sub-zero temperatures can cause airway damage that may lead to EIB. Prolonged exercise can also elicit greater immune perturbations than short-duration exercise. However, the influence of exercise duration on lung function and systemic immunity in sub-zero temperatures has not been established. Additionally, it is currently unknown whether atopic disposition, which is risk factor for EIB, influences respiratory responses in a sub-zero climate. The aim of this study was to compare respiratory and systemic immune responses to two cold air running trials of short and long duration, as well as to examine whether the responses differed between atopic and non-atopic subjects.

Methods

Eighteen healthy, endurance-trained subjects (males/females: 14/4; age: 29.4 ± 5.9 years old; BMI: 23.1 ± 1.7; atopic/non-atopic: 10/8) completed two moderate-intensity climate chamber running trials at − 15 °C, lasting 30 and 90 min, in a randomized, cross-over design. Lung function (spirometry and impulse oscillometry), serum CC16, respiratory symptoms, and blood leukocyte counts were examined before and after the trials.

Results

Lung function was not significantly affected by exercise or exercise duration. CC16 concentration increased after both trials (p = 0.027), but the response did not differ between trials. Respiratory symptom intensity was similar after each trial. There was a greater increase in neutrophils (p < 0.001), and a decrease in eosinophils (p < 0.001) after the 90-min bout. The 90-min protocol increased X5 compared to the 30-min protocol only in atopic subjects (p = 0.015) while atopy increased lower airway symptoms immediately after the 90-min session (p = 0.004).

Conclusions

Our results suggest that a 90-min bout of moderate-intensity exercise at − 15 °C does not cause substantial lung function decrements, airway epithelial damage or respiratory symptoms compared to 30 min running in the same environment, despite a heightened redistribution of white blood cells. However, exercise at − 15 °C may cause airway injury and evoke respiratory symptoms, even at moderate intensity. Atopic status may lead to greater peripheral bronchodilation and higher frequency of respiratory symptoms after long-duration exercise in cold.

Trial registration: 01/02/2022 ISRCTN13977758. This trial was retrospectively registered upon submission to satisfy journal guidelines. The authors had not initially registered the study, as the intervention was considered to be a controlled simulation of exercise in a naturally occurring environment (i.e. sub-zero air) for healthy volunteers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02029-2.

Risk factors associated with acute respiratory illnesses in athletes: a systematic review by a subgroup of the IOC consensus on ‘acute respiratory illness in the athlete’

Objective

To review risk factors associated with acute respiratory illness (ARill) in athletes, including non-infectious ARill and suspected or confirmed acute respiratory infections (ARinf).

Design

Systematic review.

Data sources

Electronic databases: PubMed-Medline, EbscoHost and Web of Science.

Eligibility criteria

Original research articles published between January 1990 and July 2020 in English were searched for prospective and retrospective full text studies that reported quantitative data on risk factors associated with ARill/ARinf in athletes, at any level of performance (elite/non-elite), aged 15–65 years.

Results

48 studies (n=19 390 athletes) were included in the study. Risk factors associated with ARill/ARinf were: increased training monotony, endurance training programmes, lack of tapering, training during winter or at altitude, international travel and vitamin D deficits. Low tear-(SIgA) and salivary-(IgA) were immune biomarkers associated with ARill/ARinf.

Conclusions

Modifiable training and environmental risk factors could be considered by sports coaches and athletes to reduce the risk of ARill/ARinf. Clinicians working with athletes can consider assessing and treating specific nutritional deficiencies such as vitamin D. More research regarding the role and clinical application of measuring immune biomarkers in athletes at high risk of ARill/ARinf is warranted.

PROSPERO registration number

CRD42020160928.

Overuse of Short-Acting Beta-2 Agonists (SABAs) in Elite Athletes: Hypotheses to Explain It

The use of short-acting beta-2 agonists (SABAs) is more common in elite athletes than in the general population, especially in endurance sports. The World Anti-Doping Code places some restrictions on prescribing inhaled β2-agonists. These drugs are used in respiratory diseases (such as asthma) that might reduce athletes’ performances. Recently, studies based on the results of the Olympic Games revealed that athletes with confirmed asthma/airway hyperresponsiveness (AHR) or exercise-induced bronchoconstriction (EIB) outperformed their non-asthmatic rivals. This overuse of SABA by high-level athletes, therefore, raises some questions, and many explanatory hypotheses are proposed. Asthma and EIB have a high prevalence in elite athletes, especially within endurance sports. It appears that many years of intensive endurance training can provoke airway injury, EIB, and asthma in athletes without any past history of respiratory diseases. Some sports lead to a higher risk of asthma than others due to the hyperventilation required over long periods of time and/or the high environmental exposure while performing the sport (for example swimming and the associated chlorine exposure). Inhaled corticosteroids (ICS) have a low efficacy in the treatment of asthma and EIB in elite athletes, leading to a much greater use of SABAs. A significant proportion of these high-level athletes suffer from non-allergic asthma, involving the th1-th17 pathway.

A heat and moisture-exchanging mask impairs self-paced maximal running performance in a sub-zero environment

Purpose

Heat-and-moisture-exchanging devices (HME) are commonly used by endurance athletes during training in sub-zero environments, but their effects on performance are unknown. We investigated the influence of HME usage on running performance at − 15 °C.

Methods

Twenty-three healthy adults (15 male, 8 female; age 18–53 years; \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text O}_{2peak}$$\end{document}V˙O2peak men 56 ± 7, women 50 ± 4 mL·kg⁻¹·min⁻¹) performed two treadmill exercise tests with and without a mask-style HME in a randomised, crossover design. Participants performed a 30-min submaximal warm-up (SUB), followed by a 4-min maximal, self-paced running time-trial (TT). Heart rate (HR), respiratory frequency (f_R), and thoracic area skin temperature (T_sk) were monitored using a chest-strap device; muscle oxygenation (SmO₂) and deoxyhaemoglobin concentration ([HHb]) were derived from near-infra-red-spectroscopy sensors on m. vastus lateralis; blood lactate was measured 2 min before and after the TT.

Results

HME usage reduced distance covered in the TT by 1.4%, despite similar perceived exertion, HR, f_R, and lactate accumulation. The magnitude of the negative effect of the HME on performance was positively associated with body mass (r² = 0.22). SmO₂ and [HHb] were 3.1% lower and 0.35 arb. unit higher, respectively, during the TT with HME, and T_sk was 0.66 °C higher during the HME TT in men. HR (+ 2.7 beats·min⁻¹) and T_sk (+ 0.34 °C) were higher during SUB with HME. In the male participants, SmO₂ was 3.8% lower and [HHb] 0.42 arb. unit higher during SUB with HME.

Conclusion

Our findings suggest that HME usage impairs maximal running performance and increases the physiological demands of submaximal exercise.

Respiratory impact of a grand tour: insight from professional cycling

PURPOSE

The aim of this study was to evaluate the respiratory function and symptom perception in professional cyclists completing a Grand Tour (GT).

METHODS

Nine male cyclists completed La Vuelta or Tour de France (2018/19). At study entry, airway inflammation was measured via fractional exhaled nitric oxide (FeNO). Respiratory symptoms and pulmonary function were assessed prior to the first stage (Pre-GT), at the second rest day (Mid-GT) and prior to the final stage of the GT (Late-GT). Sniff nasal inspiratory pressure (SNIP) was assessed at pre and late-GT timepoints.

RESULTS

Seven cyclists reported respiratory symptoms during the race (with a prominence of upper airway issues). Symptom severity increased either mid or late-GT for most cyclists. A decline in FEV₁ from pre-to-mid GT (- 0.27 ± 0.24 l, - 5.7%) (P = 0.02) and pre-to-late GT (- 0.27 ± 0.13 l, - 5.7%) (P < 0.001) was observed. Similarly, a decline in FVC (- 0.22 ± 0.17 l, - 3.7%) (P = 0.01) and FEF_25-75 (- 0.49 ± 0.34 l/s, - 11%) (P = 0.02) was observed pre-to-late GT. Overall, eight (89%) and six (67%) demonstrated a clinically meaningful decline (> 200 ml) in FEV₁ and FVC during the GT follow-up, respectively. SNIP remained unchanged pre-to-late GT (n = 5), however, a positive correlation was observed between ΔSNIP and ΔFVC (r = 0.99, P = 0.002).

CONCLUSION

GT competition is associated with a high prevalence of upper respiratory symptoms and a meaningful decline in lung function in professional cyclists. Further research is now required to understand the underpinning physiological mechanisms and determine the impact on overall respiratory health and elite cycling performance and recovery.

Asthma in Competitive Cross-Country Skiers: A Systematic Review and Meta-analysis

INTRODUCTION

In cross-country skiing, the repetitive ventilation of large amounts of cold and dry air strains the airways. The aim of this systematic review was to establish an overview of the current literature on asthma in cross-country skiers, biathletes and ski-orienteers.

METHODS

Six databases were searched on August 29, 2019. The search yielded 2161 articles. Thirty articles fulfilled the search criteria and were pooled together for a qualitative synthesis. Eight articles were included in the meta-analysis on the prevalence of asthma and the use of asthma medication.

RESULTS

According to the meta-analysis, the prevalence of self-reported physician-diagnosed asthma in skiers was 21% (95% CI 14-28%). The onset age of asthma was higher in skiers than in non-skiers with asthma. The prevalence of asthma medication use was on average 23% (CI 95% 19-26%). Several studies reported that asthma was underdiagnosed in skiers, as previously healthy skiers without a prior asthma diagnosis or medication use were frequently found to fulfill diagnostic criteria for asthma according to lung function tests. Studies using bronchial biopsy demonstrated that eosinophilic asthma is not detected in skiers with asthma as often as it is in non-skiers with asthma and that there are signs of airway inflammation even in non-asthmatic skiers.

CONCLUSION

Our findings suggest that the accuracy and coverage of diagnosing asthma in skiers has improved over the recent decades. However, the optimal treatment and natural course of asthma in this population remain unclear. Future research should investigate how the intensity of training, airway infections and their treatment affect the development of asthma among skiers.

PRD REGISTRATION NUMBER

CRD42017070940.

Are Respiratory Responses to Cold Air Exercise Different in Females Compared to Males? Implications for Exercise in Cold Air Environments

Research has shown that cold air exercise causes significant respiratory dysfunction, especially in female athletes. However, how female and male athletes respond to cold air exercise is not known. Thus, we aimed to compare acute respiratory responses (function, recovery and symptoms) in males and females after high-intensity cold air exercise. Eighteen (nine female) athletes completed two environmental chamber running trials at 0 °C and −20 °C (humidity 34 ± 5%) on different days in a randomized starting order. Spirometry was performed pre, 3, 6, 10, 15 and 20 min post. Respiratory symptoms were measured posttrial and heart rate and rating of perceived exertion were assessed during each trial. No significant differences in delta change (pre to post) were found at either temperature between sexes for FEV₁, FVC, FEF50% and FEF25–75%. At −20 °C, FEV₁ decreased similarly in both sexes (males: 7.5%, females: 6.3%) but not at 0 °C, p = 0.003. Postexertion respiratory function recovery and reported symptoms were not different between sexes at either temperature. These results indicate no sex-based differences in acute respiratory responses (function, recovery and symptoms) to cold air exercise. However, intense exercise at −20 °C is challenging to the respiratory system in both sexes and may lead to altered respiratory responses compared to mild winter conditions like 0 °C.

The impact of a heat and moisture exchange mask on respiratory symptoms and airway response to exercise in asthma

Respiratory symptoms, including cough, are prevalent in individuals with asthma when exercising. This study investigates whether a heat and moisture exchanger (HME) face mask is effective in modulating exercise-induced bronchoconstriction (EIB) and post-exercise cough in a cold, dry environment in individuals with asthma.

Twenty-six participants diagnosed with asthma (20 males, 6 females) completed three cycling exercise challenges at 8°C and 24% relative humidity in a randomised order. Participants wore either an HME mask (MASK), sham mask (SHAM), or no mask (CONT). Following a 3-min warm-up, participants completed 6-min cycling at 80% peak power output. Before and after exercise, maximal flow-volume loops were recorded. Post-exercise cough was monitored with a Leicester Cough Monitor (LCM) for 24 h. Results were analysed using repeated-measures ANOVA and Friedman's tests and data were presented as the mean±sd or median (interquartile range (IQR)).

Eleven participants failed to demonstrate EIB (i.e. >10% fall in forced expiratory volume in 1 s after exercise) and were removed from analysis. The percentage fall in forced expiratory volume in 1 s following exercise in CONT was greater than MASK (MASK: −6% (7%), SHAM: −11% (11%), CONT: −13% (9%); p<0.01). No difference was found between exercise in cough count per hour over the 24-h monitoring period or the number of coughs in the first hour after exercise.

HME masks can attenuate EIB when exercising in cold, dry environments. The SHAM mask may not have been entirely inert, demonstrating the challenges of running randomised control trials utilising control and sham conditions.

Heat and moisture exchanger masks can reduce bronchoconstriction in individuals with exercise-induced bronchoconstriction when exercising in cold, dry environmentshttps://bit.ly/2JKeLnX

Exercise in Sub-zero Temperatures and Airway Health: Implications for Athletes With Special Focus on Heat-and-Moisture-Exchanging Breathing Devices

Asthma is highly prevalent among winter endurance athletes. This "occupational disease" of cross-country skiers, among others, was acknowledged during the 1990s, with the pathogenesis attributed to repeated and prolonged exposure to cold, dry air combined with high rates of ventilation during exercise. Nevertheless, more than 25 years later, the prevalence of asthma among Scandinavian cross-country skiers is unchanged, and prevention remains a primary concern for sports physicians. Heat-and-moisture-exchanging breathing devices (HMEs) prevent exercise-induced bronchoconstriction in subjects with pre-existing disease and may have potential as a preventative intervention for healthy athletes undertaking training and competition in winter endurance sports. Herein we firstly provide an overview of the influence of temperature and humidity on airway health and the implications for athletes training and competing in sub-zero temperatures. We thereafter describe the properties and effects of HMEs, identify gaps in current understanding, and suggest avenues for future research.

Effects of a heat and moisture exchanger on respiratory function and symptoms post-cold air exercise

PURPOSE

Exercise at temperatures below -15°C induces drying and cooling of lung airways which causes exercise-induced bronchoconstriction (EIB) and respiratory symptoms, especially in winter sport athletes. The objective of this study was to evaluate whether a heat and moisture exchanger (HME) worn during intense cold air exercise improves lung function and reduces respiratory symptoms in healthy winter sport athletes.

METHODS

Seven active males and six active females (maximum oxygen uptake 61.9 ± 6.9 and 52.2 ± 5.3 mL/kg/min), all active or former winter sport athletes, completed running trials with and without HME in random order on 2 days in an environmental chamber (-20°C temperature, humidity 46.2%). Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV₁ ), forced expiratory flow at 25%-75% (FEF_25%-75% ), and FEF at 50% (FEF_50% ) were measured pre- and post-exercise (3, 6, 10, 15, and 20 minutes). Respiratory symptoms were reported after exercise.

RESULTS

Significant interaction effects were observed for FEV₁ and FEF_25%-75% . Mean decrease of FVC (-5.9%, P ≤ .001) and FEV₁ (-4.2%, P = .003) was largest 3 minutes post-exercise without HME. There was an increase of FEV₁ , FEF_25%-75% , and FEF_50% post-exercise compared to pre-exercise with HME. More respiratory symptoms overall were reported without HME (P = .046).

CONCLUSION

Intense cold air exercise likely causes transient acute bronchoconstriction and symptoms of cough in individuals participating in winter sports. However, this study finds that the application of an HME during intense cold air exercise improves lung function and reduces prevalence of EIB-associated symptoms compared to unprotected intense cold air exercise.

Cold air exercise screening for exercise induced bronchoconstriction in cold weather athletes

Exercise Induced Bronchoconstriction (EIB) prevalence in cold weather athletes is high. Currently, no standardized cold air exercise provocation test exists. Thus we aimed to determine EIB prevalence using a Cold Air Test (CAT; 5 km outdoor running; -15 °C) compared to the most common EIB screen the Eucapnic Voluntary Hyperpnea (EVH) test in cold weather athletes. Sixteen (9 male; 20-35 years old) cold weather athletes completed EVH 72 h before CAT. Spirometry, Fractional Expired Nitric Oxide (FENO), respiratory symptoms were measured and atopy status was determined. Five and 7 participants were EIB + on the EVH and CAT, respectively. Level of agreement was 50% between tests. FEV₁ recovery was significantly prolonged and Peak Expiratory Flow was decreased after CAT compared to EVH. Predictive characteristics of EIB + included FENO >12 ppb, FEV₁/FVC ratio (<0.75) and BMI < 20. EVH does not always reflect EIB triggered by cold weather exercise. More research is required to understand the best EIB screens for cold weather athletes.

Asthma and exercise-induced respiratory disorders in athletes. The position paper of the Polish Society of Allergology and Polish Society of Sports Medicine

Exercise-induced respiratory symptoms describe acute airway narrowing that occurs as a result of exercise. It includes exercise-induced bronchoconstriction (EIB) and exercise-induced asthma (EIA) issues. To provide clinicians with practical guidelines, a multidisciplinary panel of stakeholders was convened to review the pathogenesis of EIB/EIA and to develop evidence-based guidelines for the diagnosis and treatment. Recommendations for the diagnosis and treatment of EIB were developed. High-intensity exercise in polluted environment (cold air, humidity, contamination, allergens) may increase the risk of EIB and asthma symptoms in athletes. Diagnostic procedures should include history taking, physical examination, atopy assessment and functional tests of the respiratory system. A strong recommendation was made for regular use of inhaled glucocorticosteroids and avoidance of short-acting β₂-agonists as the only treatment. The treatment of asthma in athletes should always take into account current anti-doping regulations. This position paper reflects the currently available evidence.

Cough in exercise and athletes

In the general population, particularly in individuals with asthma, cough is a common symptom, often reported after exertion, although regular exercise may be associated with a reduction in the prevalence of cough. In athletes, exercise-induced cough is also a particularly frequent symptom. The main etiologies of cough in athletes are somewhat similar to non-athletes, including asthma/airway hyperresponsiveness, upper airways disorders such as allergic or non-allergic rhinitis, and exercise-induced laryngeal obstruction, although these conditions are more frequently observed in athletes. In these last, this symptom can also be related to the high ventilation and heat exchange experienced during exercise, particularly during exposure to cold/dry air or pollutants. However, gastroesophageal reflux, a common cause of cough in the general population, despite being highly prevalent in athletes, has not been reported as a main cause of cough in athletes. Cough may impair quality of life, sleep and exercise performance in the general population and probably also in athletes, although there are few data on this. The causes of cough should be documented through a systematic evaluation, the treatment adapted according to identified or most probable cough etiology and pattern of presentation, while respecting sports anti-doping regulations. More research is needed on exercise-induced persistent cough in the athlete to determine its pathophysiology, optimal management and consequences.

Asthma and exercise-induced respiratory symptoms in the athlete: new insights

PURPOSE OF REVIEW

Asthma and exercise-induced bronchoconstriction (EIB) are common in the athlete and can interfere with sport performances. In this review, we report recent findings on the prevalence, diagnosis and evaluation of these conditions, in addition to specific issues regarding their treatment and antidoping regulations.

RECENT FINDINGS

Recent studies confirmed the high prevalence of exercise-induced respiratory symptoms, asthma and EIB, in athletes and showed that these conditions are still underdiagnosed and undertreated. Recent studies highlight the suboptimal use of asthma medication in asthmatic and allergic athletes. Regarding the diagnosis and treatment, questions about the role and criteria for positivity of eucapnic voluntary hyperpnea test were raised. It was confirmed that there is a subgroup of athletes with poor response to asthma medication. Finally, regarding antidoping regulations, new methods and changes in criteria for urinary bronchodilator thresholds were suggested.

SUMMARY

Recent publications confirm that exercise-induced respiratory symptoms, asthma and EIB are common in athletes but often unrecognized and not optimally or successfully treated. It was suggested that current criteria for diagnostic bronchoprovocation test responses could be reassessed, as well as antidoping criteria for β2-agonists urinary levels. There is a need for more research on prevention of airways dysfunction in athletes, identification of different asthma phenotypes and the benefits of standard asthma medication in this population.

Cough reflex sensitivity after exercise challenge testing in children with asthma

Bronchial challenge tests are commonly used in clinical medicine and research. The aim of this study was to clarify changes of cough reflex sensitivity before and after exercise challenge testing in asthma children. 42 asthmatic children were submitted to cough reflex sensitivity measurement - capsaicin aerosol in doubling concentrations (from 0.61 to 1250 micromol/l) was inhaled by a single breath method - before and after exercise challenge testing. Concentrations of capsaicin causing two (C2) and five coughs (C5) were reported. Children' (31 boys and 11 girls, mean age 14.05 ± 2.08 yrs) cough reflex sensitivity (median, with the 95% CI) for C2 was before exercise challenge testing 9.77 (6.10-10.99) micromol/l vs. children' C2 after it 7.32 (6.10-14.65) (P = 0.58 for the Wilcoxon two sample paired test). Children' C5 was before exercise challenge testing 19.53 (14.65-80.57) micromol/l vs. C5 after it 39.06 (24.42-58.59) micromol/l (P = 0.09 for the Wilcoxon two sample paired test). We conclude that cough reflex sensitivity was not significantly changed after exercise challenge testing in children with asthma.

Cough in exercise and athletes

Cough is the most common respiratory symptom reported by athletes and can significantly impact on health status, ability to train and athletic performance. The presence of cough in an athlete is typically taken to indicate exercise-induced bronchoconstriction (EIB), yet in many athletes with chronic cough there is no objective evidence of airway hyper-responsiveness (AHR) or heightened airway inflammation. Moreover, cough in athletes often fails to respond to a therapeutic asthma strategy, thus further work is urgently needed to progress our understanding of the pathophysiology of exercise-associated cough in this unique population. This article provides an overview of the current state of knowledge of exercise-associated cough in athletes. The article summarises our understanding of pathophysiological basis of cough in this context and provides a pragmatic clinical approach to this problem.

Lack of desensitization of the cough reflex in ovalbumin-sensitized rabbits during exercise

Introduction

Cough is a major symptom of asthma frequently experienced during exercise but little is known about interactions between cough and exercise. The goal of our study was to clarify the potential modulation of the cough reflex (CR) by exercise in a spontaneously breathing anaesthetized animal model of airway eosinophilic inflammation.

Materials & methods

Ten ovalbumin (OVA) sensitized adult rabbits and 8 controls were studied. The ventilatory response to direct tracheal stimulation, performed both at rest and during exercise was determined to quantify the incidence and the sensitivity of the CR.

Broncho-alveolar lavages (BAL) and cell counts were performed to assess the level of the airway inflammation following OVA-induced sensitization. Exercise was mimicked by Electrically induced hindlimb Muscular Contractions (EMC).

Results

Among 494 tracheal stimulations, 261 were performed at rest and 233 at exercise. OVA challenges in sensitized rabbits caused a significant increase in the percentage of eosinophils (p = 0.008) in BAL. EMC increased minute ventilation by 36% and 35% in OVA and control rabbits respectively, compared to rest values. The sensitivity of the CR decreased during exercise compared to baseline in control rabbits (p = 0.0313) while it remained unchanged in OVA rabbits.

Conclusion

The desensitization of the CR during exercise in control rabbits was abolished in OVA rabbits. The precise role of airway inflammation in this lack of CR desensitization needs to be further investigated but it might contribute to the exercise-induced cough in asthmatics.