Among the myriad symptoms that people can struggle with during acute and chronic (aka long) COVID-19 infection, few are more bothersome to endurance athletes than breathing restrictions and other lung-related issues. These can persist as they resume training and try to build back up to racing.
In this article, we’ll explore how the virus could be impacting some of your athletes’ lung function and share experts’ breathing techniques to help get them back to full capacity.
Let’s start by examining how COVID-19 infection affects the lungs on a biological level. According to MeiLan Han, M.D., a professor of medicine in the Division of Pulmonary and Critical Care at the University of Michigan, “the COVID-19 virus enters the respiratory tract and takes over the cells lining your respiratory tract, turning them into virus-producing machines that in turn coat your entire respiratory tract with viral particles.” The reason we get sick is that there’s a war going on between the virus and your lungs.”
This battle causes your lungs and airways to become inflamed as your immune system kicks into high gear to try and take out the threat. This is the first way breathing function can become compromised when someone has COVID.
“The cells that normally regenerate the lung lining are also killed off,” Han continued.[1] Even if a COVID-19 infection doesn’t trigger pneumonia or other knock-on conditions, it can lead to coughing, wheezing, shortness and shallowness of breath and rapid mouth breathing that increases the body’s stress response. The soft tissues around the rib cage and thoracic spine can become sore and stiff, which is exacerbated by coughing. A study published in The Lancet Respiratory Medicine found that when someone has this annoying and often painful symptom, it lasts for an average of 19 days.[2]
COVID-19 and Endurance Athletes’ Lung Function
COVID-19 is difficult enough for the general population to tackle, but it can be particularly troublesome for endurance athletes. In theory, you might think that your clients are better able to handle the virus than most. After all, they have a large lung capacity, a high degree of aerobic fitness, and the capability to utilize oxygen more efficiently during exercise.
However, it’s unclear if such capabilities are actually transferable to fighting the virus. While there isn’t a comprehensive study of endurance athletes, plenty of anecdotal evidence suggests they can be hit just as hard.
Dirk Friel is the co-founder and chief evangelist of TrainingPeaks. He was a professional road cyclist from 1992 to 2002 and a coach from 1997 to 2007, guiding masters and pro athletes to world tour victories and a top-10 placing in the Tour de France. Starting in June 2022, Friel suffered from COVID for five weeks. “My main symptom was a dry cough during the day, which got worse when exercising,” he said. “I only had restricted breathing issues when I exercised and got my heart rate near or above 140 or so.”
His experience highlights one of the main challenges regarding COVID and your athletes: the very activities that are supposed to develop their aerobic capacity can be the ones that aggravate existing issues and possibly even delay recovery. Specific sessions can prove more demanding than others, even if an athlete previously wouldn’t have considered the equivalent effort to be taxing while fully healthy. “My cough would get worse within my training session and especially when I got near my threshold pace,” Friel said. “I would continue coughing intermittently after the workout as well. It all had to do with my respiration and heart rate. Low intensity did not cause the cough.”
Wearables, heart rate monitors and other kinds of technology can prove helpful as you try to quantify the impact of COVID on your clients’ training — and, if you’re dealing with the virus too, your own workouts. Friel combined his subjective self-evaluation with some hard data that painted a fuller picture of how COVID impacted his cardiovascular function.
“I certainly had less capability to deliver oxygen. My power output was about 40% less than what I was used to,” Friel said.
Dirk Friel
Friel has since fully recovered from COVID after taking “four easy weeks with no intensity” to let his cough cease, and his output has since returned to where it was before being infected by the virus. Yet other athletes have continued to struggle far beyond acute infection.
In a recent TrainingPeaks simple survey, 52% of coaches who responded stated that at least some of their clients were experiencing persistent COVID symptoms, which has become known as “long COVID.”
These symptoms are consistent with one of the only peer-reviewed papers on how those suffering from ongoing symptoms deal with the demands of exercise. Forty-one participants still struggled with shortness of breath three months after initial COVID infection. They were asked to ride a stationary bike to exhaustion while researchers monitored cardiac measures like stroke volume and heart rate and those pertaining to breath, such as VO2 max, carbon dioxide (CO2) levels and breathing rate. During the experiment, 88% of participants displayed dysfunctional breathing or a ventilation problem. And 60% had a circulatory issue, which included an early onset of their anaerobic threshold, reduced VO2 max and an abnormal VE/VCO2 slope (an indicator of suboptimal ventilation efficiency).[3]
In a commentary on these results, founder and director of Health Rising, Cort Johnson, noted that even if someone’s output metrics seem fine on the surface, they could still be experiencing underlying breathing difficulties due to COVID. “A normal peak VO2 was found in almost half the participants in this study,” he wrote. “Without the extra assessments done in this paper, it would have obscured the fact that almost all the patients with normal peak V02 levels exhibited unusual breathing problems – and unusual breathing patterns can, by themselves, affect exercise tolerance.”[4] This study was not conducted on athletes, but some of the same issues could be just as prevalent among your athletes.
Using Breathwork to Battle Acute and Chronic COVID
It’s all very well for someone to try and replicate the kind of clinical evaluation performed in that study if they’re struggling to come back from COVID, but doing so would be expensive, stressful and time-consuming. When I reached out to Patrick McKeown, a renowned breathing expert and author of the bestselling books “The Oxygen Advantage” and “The Breathing Cure,” he explained that your clients can easily obtain their own BOLT (body oxygen level test) score without needing equipment or a doctor’s visit. To do so, ask them to:
- Take a normal breath in and out through their nose
- Hold their breath and pinch their nose closed
- Let go of the nose and take another normal nasal breath when they feel a moderate desire to breathe or their breathing muscles involuntarily contract. The BOLT score is the number of seconds that they held their breath.
“In long-COVID patients, we’re seeing BOLT scores of four or five, which would normally indicate that someone needs medical care,” McKeown said. This could be explained by low carbon dioxide (CO2) tolerance, which clinicians at Mount Sinai Health System found among most long-COVID patients. [5] He typically suggests increasing the BOLT score — and with it, CO2 tolerance – with exercises like holding the nose and increasing the number of paces you can walk before feeling the need to breathe. But he said that this is too stressful for anyone with ongoing COVID symptoms and that other breathing techniques that can be beneficial to healthy people – such as those involving longer breath holds and extended exhales — might actually make COVID lung issues worse. Instead, McKeown recommends a simple, shorter breath-holding protocol to increase the BOLT score to 25 or above, whereby your athletes:
- Take a normal breath with a nasal inhale and exhale
- Pinch their nose and hold their breath for a couple of seconds
- Let go of the nose, breathe in, and breathe normally for 10 seconds
- Repeat the cycle for two to five minutes, five to six times daily
- Increase the number of minutes per set up to 10, as they feel comfortable
Restoring Vagal Tone and Autonomic Nervous System Balance
A Spanish pilot study of 348 long-COVID patients found that 27% had thickened or inflamed vagus nerves, and two-thirds had at least one symptom of vagus nerve dysfunction like breathing issues and an abnormally high resting heart rate.[6] While there’s ongoing research into the electrical stimulation of the vagus nerve (which regulates the cardiorespiratory function and modulates the autonomic nervous system so that it’s not stuck in a sympathetic flight-or-flight mode), there are also manual ways to do so.
“Holding your breath for even a couple of seconds will stimulate the vagus nerve, as will slow nasal breathing the rest of the day,” McKeown explained. “We do slow exhalations with lateral expansion and contraction of the lower ribs because if you slow breathe, you can increase alveolar ventilation, especially if your blood-oxygen saturation is dropping.”
Another breathing technique that McKeown said will stimulate the vagus nerve is humming. Doing so also stimulates the paranasal sinuses, which two Swedish researchers found increases the production of nitric oxide fifteenfold. [7] This gas increases oxygen uptake and has antiviral properties, which has prompted further research on its use for treating long COVID. To incorporate humming into their breathwork, your clients should:
- Take a normal nasal inhale
- Make a “hmmm” noise as they exhale through their nose
- Repeat for three to five minutes
Jill Miller, the founder of Tune Up Fitness and author of the forthcoming book “Body by Breath,” told me that downshifting the autonomic nervous system into a parasympathetic recovery state can also be achieved by combining breathing in three different positions with input from a soft mobility ball.
“One of the first things hospitals did with COVID patients was to rotate them to increase alveolar space and ventilation and move excess mucus out of certain areas using gravity,” she said. Miller believes this also applies to any of your athletes suffering from long COVID. The following technique provides “mobilization of the thoracic spine and ribs,” she said. “Plus, you’re manipulating the lungs and the heart, so you’re getting sensory inputs into the vagus nerve while improving diaphragm function.” To do this three-part exercise, your clients should:
- Place a Coregeous ball or similar tool halfway down their spine
- Cross their arms under their head or use a small pillow to support it
- Take slow breaths with inhales that start in the abdomen and flow up into the middle of the torso
- Repeat for three to five minutes and then turn onto one side, placing the ball between the side of their rib cage and the floor
- Breathe in and out calmly for another few minutes, and then repeat on the other side
- Lie on their front and place the ball under their sternum, crossing the arms or using a pillow to support their head
- Breathe into the ball for another few minutes
Breathing Right When Returning to Training
All the exercises above can be performed at any stage of your athletes’ recovery from COVID to support the healing process and mitigate the heightened stress and anxiety-related effects — such as breathing dysfunction and sleep disruption — that can exacerbate symptoms. Once they resume training again, McKeown recommends that they use nasal breathing as a self-limiting mechanism to help avoid going too hard too soon.
“There will be a greater risk of overtraining when there’s increased breathlessness,” he said. “I’d suggest only breathing through the nose because when you do that, there’s a resistance to your breath that’s going to slow you down. You’ll increase oxygen uptake, and there will be less air loss due to dead space in the lungs. This will improve ventilation and gas exchange, both of which can be compromised by COVID. Nasal breathing also helps you remain calm.”
He went on to advise that if one of your athletes feels ready to try light training again, they should only proceed if their BOLT score is at least 15. If it is before a session but upon retesting the next day has dipped under that mark, “it could be a sign that they’ve overtaxed themselves and haven’t properly recovered,” McKeown said.
In this case, a planned run could be downgraded in intensity or replaced with a walk interspersed with breathing exercises. “In terms of lung health, returning back to normal can be slow progress, but whatever chance you have to breathe through your nose will help,” he added.
References
[1] Kelly Malcom, “Taking Care of Your Lungs During COVID and Beyond,” Michigan Health, November 8, 2021, available online at https://healthblog.uofmhealth.org/wellness-prevention/taking-care-of-your-lungs-during-covid-and-beyond.
[2] Woo-Jung Song et al, “Confronting COVID-19-Associated Cough and the Post-COVID Syndrome: Role of Viral Neurotropism, Neuroinflammation, and Neuroimmune responses,” The Lancet Respiratory Medicine, May 1, 2021, available online at https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(21)00125-9/fulltext.
[3] Donna M Mancini et al, “Use of Cardiopulmonary Stress Testing for Patients with Unexplained Dyspnea Post–Coronavirus Disease,” JACC: Heart Failure, December 2021, available online at https://www.sciencedirect.com/science/article/pii/S2213177921004807?via%3Dihub.
[4] Cort Johnson, “Uneasy Breaths: Strange Breathing Patterns in Long COVID May Contribute to Exercise Intolerance,” Health Rising, July 3, 2022, available online at https://www.healthrising.org/blog/2022/07/03/exericse-long-covid-breathing-patterns.
[5] Meghan O’Rourke, “Unlocking the Mysteries of Long COVID,” The Atlantic, March 8, 2021, available online at https://www.theatlantic.com/magazine/archive/2021/04/unlocking-the-mysteries-of-long-covid/618076.
[6] “Long COVID Could be Linked to the Vagus Nerve,” Scimex, February 12, 2022, available online at https://www.scimex.org/newsfeed/long-covid-could-be-linked-to-the-vagus-nerve.
[7] Eddie Weitzberg and Jon O N Lundberg, “Humming Greatly Increases Nasal Nitric Oxide,” American Journal of Respiratory and Critical Care Medicine, July 15, 2002, available online at https://pubmed.ncbi.nlm.nih.gov/12119224.
