Dr James Hull, Royal Brompton Hospital, UK
From March 2020, much has changed in our understanding of the impact of COVID-19 on active individuals and the debilitating effects of long COVID. In the early days of the pandemic, it was considered that COVID-19 had the most devastating impact on over 40s and individuals with comorbidities. The data that emerged over time suggested that being physically active and partaking in regular exercise appeared to be associated with a lower risk of hospitalisation and other severe complications.
This led to the prominent media messaging promoting the advantages of physical fitness. It was thought that physically fit individuals could potentially handle exposure to the virus better than others.
However, it became increasingly apparent that athletes were not protected against the novel virus. Although it was rare for athletes be hospitalised for COVID-19 related care, even elite athletes were heavily affected by the virus and its lingering effects. Athletes in their prime and considered to be at their peak competitive performance struggled to return to their pre-existing fitness levels, several weeks after developing COVID-19 infection.
Leading COVID-19 rehabilitation in athletes
I was part of a clinical team working with the English Institute of Sport, helping the Great Britain team prepare for the Tokyo Olympic Games in 2021. We closely monitored the impact of COVID-19 in this group of elite athletes, analysing the symptoms and duration of illness, as well as the recovery time for them to be cleared and able to return to sport. The study covering the first wave and second waves was published in the British Journal of Sports Medicine.
Out of a total of 147 athletes, COVID-19 presented as a mild illness that lasted an average of 10 days. No athletes required hospital admission, however 13% were still symptomatic after 28 days, which is a prolonged period to be unwell. A quarter of athletes experienced symptoms that lasted longer than a month. This group were unable to return to sport due to fatigue and chest pain. Generally, most athletes were back in training by 3 months.
Based on the initial data and challenges athletes faced from COVID-19, we made the first set of recommendations of a ten-day resting period and seven days free of symptoms before returning to sport.
Comparing these results to those obtained in the general population from the Zoe COVID study, we found similar trends in illness duration and clinical characteristics as seen in the general population. This was despite athletes often being at the younger age range, which was thought to be a lower risk group to COVID-19.
Potential side effects
At the start of the pandemic, extrapolations from hospital data fearfully suggested that COVID-19 caused myocardial inflammation (heart damage). As a precautionary measure, athletes were recommended to slowly and gradually return to sport following COVID-19 infection to minimise the risk of developing cardiac problems.
Later, thanks to more robust data and further research, we learnt that the risk of cardiac damage was actually closer to 1 in 100 and much lower than the initial statistic of 1 in 4. This shows how our awareness and knowledge is constantly growing during the pandemic. As our understanding improves, we have updated our health recommendations for athletes.
Now, we generally recommend that athletes can return to sport after five days from disease onset, providing they don’t have chest pain or symptoms that may suggest issues in the lower chest. We need to consider whether the constraints imposed by the best available advice at the time could have extended the recovery times for athletes. They could have been negatively impacted by the amount of time they lost from the lack for training for days or weeks. This is not yet clear and difficult to disentangle, from the fact that most athletes are now vaccinated.
Slow rate of recovery
Long COVID has had varying hindering effects. Athletes report fatigue, tiring far more easily during training sessions. They are exhausted even when training at their lower threshold levels, which were viewed as their easier sessions based on their pre-COVID infection fitness levels.
They often experience or report an abnormal heart rate, even in the absence of a cardiac condition. The heart rate responds inappropriately to exercise, increasing at a greater and faster rate than athletes expected for the same workout carried out pre-COVID infection.
Difficulty getting a satisfactory breath is another common symptom; athletes feel that they can’t breathe in properly or can’t get enough breath. Further investigation of these unexplained symptoms at clinics has shown dysfunctional breathing patterns, where an increase in exercise intensity results in an erratic breath.
Is COVID-19 unique?
Historical data on other respiratory tract infections and pre-pandemic illness shows that COVID-19 symptoms last longer than other respiratory tract infections. The prevalence and prolonged impact could be due to lower respiratory infection preventing a quick return to sport.
We’ve found no differences in athletic groups, no difference between winter and summer sports, endurance vs power sports.
These findings predate Omicron. The emergence of this new variant raises further questions on the duration and impact of COVID-19. We are currently investigating how the Omicron variant affects athletes’ road to recovery, as well as unravelling the physiological effects of the vaccine on training. Anecdotally, vaccinations seem to have dramatically shortened recovery time.
What do we need to know?
Further work is still needed to determine the mechanisms associated with long COVID. Our ongoing clinical work at the Institute of Sport, Exercise and Health (ISEH), at University College London, UK is testing the effect of exercise on lung function to attempt to characterise recovery in athletes.
A key focus should be understanding how the disease affects the autonomic nervous system, a system that is affected by athletic training. This could, in at least part, explain how an abnormal heart rate, leading to dizziness and fatigue occurs in the absence of a cardiac condition. Hopefully, it could provide a clue as to how this symptom can be modulated.
We are still on a journey of understanding and there remains a great deal to learn. COVID-19 does affect athletes and can significantly delay their return to their former abilities. How COVID-19 influences this and the composite of various pathways involved remains to be answered.
The blog is based on the session presented by Dr James Hull, Royal Brompton Hospital and ISEH, UK, at the Long COVID: Mechanisms, Risk Factors, and Recovery on 22 February 2022.