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From the FasterSkier archive — posts syndicated from athletes’ and coaches’ own blogs between 2004 and 2012, kept online as published. Current coverage is at fasterskier.com.

Tag: lungs

  • Female Skiers Accumulate Airway Injury and Cough During Race Season

    Female Skiers Accumulate Airway Injury and Cough During Race Season

    Racing and training in cold weather causes airway damage and inflammation to a much greater extent for female than for male skiers.
    Racing and training in cold weather causes airway damage and inflammation to a much greater extent for female than for male skiers.

    Dr. Michael Kennedy, a researcher at the University of Alberta, is a cardiovascular specialist. He has spent time working on a variety of different projects: studying muscle oxygenation, fatigue in athletes, the relationship between fitness and injury, even the effects of caffeine.

    But recently he returned to a question which had kept him curious since his days as a wax technician with x-c.com, a Canadian senior race team in the mid-2000’s.

    “In Silver Star [early season] the big house we rented was always quiet but by the time Nationals rolled around [in March] you could hear the women hacking away while they tried to sleep,” Kennedy wrote in an email last week. “This sparked a conversation with my colleague and friend Neil Eves whom at that time was working in respiratory health… it became clear from Neil’s standpoint that the cough was not a respiratory infection, but a chronic cough much like he would see in clinical populations.”

    So last year, Kennedy and some colleagues recruited 18 Canadian women who were competing full-time as cross-country skiers, and surveyed their lung inflammation over the course of a season using a technique known as sputum sampling.

    What the team found was that, indeed, airway inflammation and injury increased significantly over course of a season in ways that were completely unrelated from the prevalence of colds and respiratory infections. By the end of the season, the cough was affecting the women’s ability to sleep and recover.

    The paper was recently published by the Scandinavian Journal of Medicine & Science in Sports.

    “We were very careful to make sure that we were investigating what we thought was inflammation and chronic cough,” Kennedy explained. “We did not test a participant at a time when they had a cold or felt they were coming down with something. It made things certainly more challenging in terms of testing, but we feel like we did a good job of not having a participant who had some sort of infection going on.”

    Kennedy explains that this syndrome is different for women and men: because women have smaller lungs, they are operating at peak airway respiration much earlier in the max-effort race or training session. That leads to greater airway damage in dry, cold weather.

    We caught up with him by phone to learn more about the study, and what it means for the health of female cross-country skiers. This interview has been edited and condensed.

    FasterSkier: So between your work on the cardiovascular system and Neil Eves’ expertise, it sounds like this was an interdisciplinary project.

    Dr. Michael Kennedy: I was always interested in respiratory issues. It’s something that lots of skiers talk about on a weekly basis.

    But yes, it really was. I know a lot about respiratory physiology because obviously the respiratory system and the cardiovascular system are deeply attached. But Neil, and working with a few key clinicians in Calgary, made it interdisciplinary. Warren Davidson, who is a respirologist, and Richard Leigh who developed the sputum analysis technique. So you put together cellular biology with clinicians and respiratory physiologists to pull off the project.

    FS: What was the process of the sputum sampling?

    MK: In our development of the project, Neil and I discussed ways in which we could explore analyzing inflammation in the lungs. Really there’s two ways you can do it. You can do it invasively through a tissue sample, so you put a scope down someone’s throat and clip off a little bit of the airway and analyze the cells within that sample. That really still is the gold standard because you have a physical tissue sample. There are some risks, and it’s very difficult on people, it’s not the funnest.

    The new technique, the sputum sample, is non-invasive. It doesn’t require being in a sterilized environment with a scope. By inhaling a high dose of what we call nebulized saline, so basically a big breath of water vapor with a lot of saline in it, which basically begins to activate and draw cells off the airway wall – by doing that, it’s like trying to scrape paint off of siding. You peel off little sputum chunks.

    Then through a deep cough that you coach the person through, you cough those out. It’s a way to basically get the same cells that you would with a physical tissue sample, without having to clip off a piece of the airway.

    FS: What were you looking for in the sample?

    MK: We went after the key inflammatory cells which would be indicative of airway injury. The key ones would be neutrophils, which are an early responders to injury, and eosinophils which are inflammatory responders. And then macrophages, which come along and are like the garbage trucks but also very involved in the inflammatory reponse. And lymphocytes which are ones that are often activators stimulating the immune system to fight the infection or the inflammation.

    FS: How did the findings link to quality of life indicators that you checked in your questionnaires?

    MK: The fundamental question was, first is there inflammation occurring that increases as you move into fall and winter month, and second, whether that leads to cough and quality of life symptoms.

    With the quality of life indicators, we chose what we believe was the most valid measure of quality of life, which is this recovery-stress questionnaire, REST-Q. We didn’t see any changes in REST-Q, because my experience with these female athletes was that they really were struggling towards the end of the season. But what we did see was certainly an increase in cough-related symptoms and disturbed sleep due to coughing bouts.

    I think what you can take home from that is that the cough is prevalent and does improve through the season, but that athletes don’t feel like athletes feel like it’s affecting their quality of life necessarily. It comes with the territory and they’re coping pretty well.

    FS: If these are longtime skiers, do you think it’s possible that they just see it as normal winter quality of life, and don’t realize that it’s abnormal?

    MK: That’s a really good point. Normal for them might be this persistent cough, and so when they fill out a quality of life index it might not seem different, even though relative to a healthy population it might be quite different.

    And I’m sure you’ve experienced post-race cough, which is frustrating and affects your conversations and you feel a tight chest and then it goes away. And you just deal with that and say, well it’s winter, that’s normal for me.

    FS: You talk about why women might be more prone to airway damage due to their smaller lungs. But because of that, women are also moving less air through their airways, right? So how does that work?

    MK: It’s an interesting phenomenon. Ironically, with the cardiovascular system, these years and years of training essentially overdevelop the cardiovascular system in relation to the respiratory system in female athletes.

    In male athletes, you get the same overdevelopment of the cardiovascular system relative to another adult at the same age, but men’s lungs are significantly larger. They have a larger capacity. So with the overdevelopment of the cardiovascular system in males, they don’t operate at this same maximum percent of airway function because they have a bigger thorax.

    In female athletes, that overdevelopment of the cardiovascular system puts them right at the upper limit of their respiratory system. They just don’t have the same amount of volume to operate with. So that does then create really really hard shear stress. So there is higher flow along the airway which potentially increases the amount of injury and inflammation.

    This has been documented a number of times, where basically on a flow-volume measurement of the respiratory and expiratory volumes and flow rates reaches the maximum very early on in intensity. So put another way, if you’re doing a VO2max test, at about 75 to 80% of VO2max female athletes are at their absolute maximum respiratory flow rate. They can’t increase their ventilation any more essentially. For male athletes that occurs at 95 or 100%. Their respiratory capacity is much more matched to their cardiovascular capacity.

    FS: In terms of how this injury happens, do you have any sense of whether it is primarily the day-to-day wear of training in winter, or is it worse if you have one super cold day, maybe weather that’s not legal to race?

    MK: I think there’s two things. One, I would be remiss to not say that these very cold days or races where organizers still have people race, they can create airway that some athletes never recover from. I’ve known female athletes who have to leave the sport because of one really horrible cold race where they did severe airway damage.

    But I think in general, there’s some knowledge of that. The athletes and participants we had in our study were pretty savvy of that. I would say that they don’t train on those days. So it really it is really that general accumulation, ventilation with dry air that happens in the fall, and cold dry air in the winter especially with intensity. And that’s just part of being a ski racer.

    As part of my concern for the well-being for endurance athletes, I’d like to say that [even without cold weather] if someone is struggling with cough symptoms, or wheeze, or tight chest, go and get screened. Go and get tested. Get a full pulmonary function test done, so that it’s medically documented and so that if there’s potential that any of the new classes of inhalers or corticosteroids could help you, that’s really helpful not only to your performance, but also probably to your long-term lung health. That’s the public health message: people really should go see a respirologist.

    FS: You mentioned at the end of the paper that there are some more testable hypotheses out there. Is this the end of your research on this subject?

    MK: No, I’ve become much more interested in this area!

    One thing is that in January we will look at the acute response. We’ll find some really cold days in Edmonton, and have some skiers run a 5 k at race pace and then measure their acute airway inflammation responses. So we will track them immediately, and then 12 hours, 24, 48, and 72 hours after. We want to try to get some more information around this post-race inflammation and cough pattern.

     

  • Rhetoric Aside, a Less Publicized Goal in WADA Ban of Asthma Medications: Healthy Athletes

    Rhetoric Aside, a Less Publicized Goal in WADA Ban of Asthma Medications: Healthy Athletes

    This is the second of two pieces looking at the use of bronchodilating drugs to treat asthma in athletes – and their changing place on WADA’s prohibited list. The first, published last week, examined the potential of Spiriva, a drug usually used in COPD patients, in treating asthma.

    ***

    Asthma, a constriction of the airways caused by one or several stimuli and also characterized by chronic airway inflammation, is especially common in winter sports such as skiing. And between the cold weather and the cardiovascular effort required by the sport, it can be difficult for asthmatics to manage their symptoms while competing. There are plenty of asthma medications out there – and yet, until two years ago, athletes had to submit at Therapeutic Use Exemption (TUE) to the appropriate anti-doping organization before they took a puff of their inhalers. Β-2 agonists, a common class of drugs that expand the airways, were categorically banned.

    Then in 2011, the World Anti-Doping Agency (WADA) removed salbutamol, one of the most common asthma medications, from its Prohibited List except for in quantities of over 1600 micrograms in 24 hours, and in 2012 gave the same treatment to formoterol, this time with a limit of 36 micrograms in 24 hours. Salmeterol, another β-2 agonist, is also not banned. All of these drugs fall into the category of bronchodilators: substances which relax and expand airways.

    “There are really no regulations requiring documentation of asthma to use a bronchodilator – that has really sort of fallen by the wayside,” said Kenneth Rundell, a former member of the International Olympic Committee’s asthma group, in an interview last week.

    Was the move simply to accommodate asthmatic athletes and cut down on the amount of TUE paperwork that was submitted, or are the three un-prohibited drugs really different than their fellow β-2 agonists which remain on the list? Other types of medications that relax and expand airways, – the entire category of these drugs are called bronchodilators – are not on the Prohibited List at all, despite achieving the same end result as β-2 agonists. So why were β-2 agonists tagged as performance-enhancing substances?

    WADA itself didn’t provide much clarification: “A substance is put on the List if it is deemed to be performance enhancing,” WADA’s Senior Manager of Media Relations and Communications, Terence O’Rourke, wrote in a brief e-mail to FasterSkier.

    Exercise and the Normal Athlete

    To understand how these drugs work and why they might be banned, one must first understand airways. Lungs respond to exercise by dilating to accommodate the added airflow and reduce constriction. And asthmatic lungs do the same thing, at least initially: for instance, a 1999 paper by Kenneth Beck of the Mayo clinic reported that during steady-state exercise, asthmatics experienced dilation of the airways for the first 15-20 minutes of exercise, before the smooth muscle started constricting. In an incremental VO2 max test, airways continuously expanded, reaching their maximum width at the end of the test and then constricting once the bout was over.

    “After a couple of minutes of exercise, even the asthmatics, except for the very severe asthmatics, will bronchodilate, just for mechanical reasons,” Rundell, who was formerly the head of the Human Physiology Laboratory at Marymount University, told FasterSkier. He added that bronchodilating drugs will further help this process in asthmatics for whom the response is lower.

    The worst effects of exercise on lung function actually come after the workout is over. In a 2010 report on exercise-induced asthma by the U.S. Department of Health and Human Services (available as PDF), the authors write that

                “Vigorous physical exercise can be followed by transient clinical signs and symptoms similar to an asthma attack and are due to post-exercise bronchoconstriction (i.e., a narrowing of the airways). Clinical symptoms include coughing, wheezing, shortness of breath, excessive mucus production, chest tightness, chest pain, or an ‘itching or scratching sensation’ in the chest. Though it is more common in people with asthma, it also occurs in people without asthma.”

    There’s a distinction between Exercise-Induced Bronchoconstriction (EIB), as described above, and asthma, which is not necessarily exercise-induced.

    So in a normal interval session, skiers with and without asthma might experience very similar lung function. Multiple studies show that non-asthmatics also experience and report coughing, wheezing, and shortness of breath. One cause is that the deeper breathing during exercise brings in more dry, cold air than the upper airways can warm and humidify before sending to the more sensitive lower airways, leading to constriction as self-defense.

    “Even with interval-type exercise, if you measure lung function during exercise, you can see some mechanical protection during exercise,” Rundell explained. “Then when they have their resting period you can see the airways narrow a bit, and then they will bronchodilate when they start exercising again, but not as much as, say, after the first four-minute bout. So over time, half an hour of that, you’ll see a gradual decline in lung function during the exercise. With steady-state exercise, you’ll see a decline as well.”

    So Why The Bans?

    In 2005, WADA chief Dick Pound told the Associated Press that athletes were faking asthma to obtain the medications, and that “we’ve caught on to their scam,” while an IOC board member from Hungary said that “We need to stop this pretending to be ill and taking dope in order to enhance the sporting performance.” Both implied that bronchodilating medications would help minimize the natural decrease in lung function of the course of a workout or race.

    It’s true that Β-2 agonists like salbutamol have been shown to help with EIB, as well as asthma. But that doesn’t exactly make them performance enhancing, as Pound had suggested. For instance, the worst bronchoconstriction comes after exercise, not during a competition – meaning that prevention of those symptoms wouldn’t lead to a performance benefit.

    “The extensive research on therapeutic doses of inhaled β2-agonsits clearly rules out any ergogenic effects,” researchers from Copenhagen wrote all the way back in 2007. “Only few studies have shown ergogenic effects of inhaled salbutamol, but these are limited by enrollment of recreational subjects. It is now a common opinion that inhaled β2-agonists in therapeutic doses has no advantageous effects in healthy athletes.”

    So, if bronchodilators aren’t performance-enhancing in regular athletes – and a large number of studies, some cited by FasterSkier in a 2011 article, have come to the same conclusion as the Copenhagen researchers – there had to be another reason that they were on the list. As it turns out, one criteria for prohibiting a medication is that it is detrimental to athletes’ health. This was a concern for WADA – salbutamol has been shown to have tough side effects when used over the long term – as well as the fact that long-term use of β-2 agonists decreases the drugs’ effectiveness over time.

    “Inhaled β2 agonists are the most effective drugs for… relieving intermittent symptoms of asthma,” the IOC’s asthma committee wrote in a 2008 report. “However… athletes who use either short- or long-acting β2-agonists on a daily basis should be advised that their effectiveness to prevent EIB will partially diminish. Frequent use of β2 agonists may also increase the bronchoconstrictor response to exercise and allergens. Strategies to avoid these problems could include restricting β2 agonists to infrequent use…”

    According to Rundell, who was part of that committee, the consensus by the IOC’s scientists and doctors seems to have had diverged from the rhetoric by its anti-doping leaders.

    “The reason was not because they provided any type of performance enhancement, but that the athletes thought that they provided performance enhancement,” Rundell told FasterSkier of the drugs’ ban. “Clenbuterol has been shown to do that, but that’s not an inhaler. At any rate, there was rampant use of the bronchodilators, so it was more out of concern for the athletes’ health that they had to provide documentation showing that they had hyper-reactive airways.”

    Publicly, however, WADA continues to assert that the bans are because the drugs are performance-enhancing, and that the organization will continue to investigate their effects.

    “The issue of β-2 agonists will continue to be a focus of WADA’s research activity in order to ensure that the administration of large doses or by systemic routes of these substances is prevented and prohibited,” WADA wrote on their website when they released the 2012 Prohibited List.