Usage of and attitudes toward heat‐ and moisture‐exchanging breathing devices among adolescent skiers

Exercise-induced bronchoconstriction in elite athletes: a narrative review

Exercise-induced bronchoconstriction (EIB) is the most common chronic disease among elite athletes and when left untreated, can impact both respiratory health and sports performance. In recent years, there has been an increase in the awareness and detection of EIB in elite athletes. This narrative review aims to evaluate the risk, prevention, diagnosis, medication, and anti-doping policies of EIB in elite athletes, and to provide more references for athletes with EIB. The results showed that athletes of endurance, winter, and water sports generally have a higher prevalence of EIB than athletes of other sports. Adaptive warm-up before formal exercise and using heat exchange masks at low temperatures are effective ways for athletes to prevent EIB. For physicians, the exercise challenge test and eucapnic voluntary hyperpnea are the recommended diagnostic methods for EIB in athletes. The treatment of athletes with EIB is medication-based, such as inhaled corticosteroids and beta-2 agonists, but current anti-doping policies should be considered when used.

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.

A breathing mask attenuates acute airway responses to exercise in sub-zero environment in healthy subjects

PURPOSE

Cold air exposure is associated with increased respiratory morbidity and mortality. Repeated inhalation of cold and dry air is considered the cause of the high prevalence of asthma among winter endurance athletes. This study assessed whether a heat- and moisture-exchanging breathing device (HME) attenuates airway responses to high-intensity exercise in sub-zero temperatures among healthy subjects.

METHODS

Using a randomized cross-over design, 23 healthy trained participants performed a 30-min warm-up followed by a 4-min maximal, self-paced running time trial in - 15 °C, with and without HME. Lung function was assessed pre- and immediately post-trials. Club cell protein (CC-16), 8-isoprostane, and cytokine concentrations were measured in plasma and urine pre- and 60 min post trials. Symptoms were assessed prior to, during, and immediately after each trial in the chamber.

RESULTS

HME use attenuated the decrease in forced expiratory volume in 1 s (FEV₁) post trials (∆FEV₁: mean (SD) HME - 0.5 (1.9) % vs. no-HME - 2.7 (2.7) %, p = 0.002). HME also substantially attenuated the median relative increase in plasma-CC16 concentrations (with HME + 27% (interquartile range 9-38) vs no-HME + 121% (55-162), p < 0.001) and reduced airway and general symptom intensity, compared to the trial without HME. No significant changes between trials were detected in urine CC16, 8-isoprostane, or cytokine concentrations.

CONCLUSION

The HME attenuated acute airway responses induced by moderate-to-maximal-intensity exercise in - 15 °C in healthy subjects. Further studies are needed to examine whether this HMEs could constitute primary prevention against asthma in winter endurance athletes.

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.