Habitual physical activity and COVID-19 2024 Glace et al

BACKGROUND: Physical activity (PA) is known to decrease COVID-19 risk factors and can attenuate symptoms of viral infections. However, difficulty exercising and fatigue are common complaints after COVID-19. It is unknown whether prior habitual PA will improve outcomes and what the time course is until full recovery of PA after COVID-19.

METHODS: Invitations were emailed to 21,933 adults who were SARS-CoV-2 positive between March 2020 and February 2021. Participants completed intake surveys and the Physical Activity History (PAH) questionnaire regarding PA during the 3-month prior to infection. Monthly thereafter, for up to 23 months, participants were emailed surveys. Scores were computed for moderate and heavy PA. Long COVID (LC) was defined as having recurring/persistent symptoms 9 months after diagnosis.

RESULTS: Overall, 993 patients completed the intake survey (age 50.7±15.8 years, BMI 27.3±9.2, 58% women); 28% had been hospitalized. One-third had recovered to their pre-infection level of PA at 9 months post-infection; this increased to 65% at one year, and 90% at two years. Higher pre-diagnosis PA reduced odds of hospitalization (P<0.05) but not of LC. Factors predictive of poor PA recovery were higher pre-diagnosis PA, shortness of breath and fatigue during acute illness, and fatigue chronically. Participants who reported ongoing symptoms had consistently poorer recovery of habitual PA compared to those not reporting chronic symptoms.

CONCLUSIONS: Habitual PA reduced odds of hospitalization but not of LC. Thirty-five percent had not returned to pre-COVID-19 levels of PA one year after infection, representing a major public health threat.

Paywall, https://www.minervamedica.it/en/jou...ical-fitness/article.php?cod=R40Y2024N07A0685

 

Evidence is building to indicate this.

Sex differences and immune correlates of Long COVID development, persistence, and resolution (2024, Preprint: BioRxiv) —

I've also posted this previously —

It's now one or two years from those statements, so worth keeping an eye for subsequent publications, particularly the paediatric data. That could shed a lot of light because you typically have completely healthy children who have developed just one disease unlike adults who may have other conditions. I haven't seen any yet from the Perth group, but we do have a recent publication from Fasano and Yonker — The Spectrum of Postacute Sequelae of COVID-19 in Children: From MIS-C to Long COVID (2024, Annual Review of Virology)

 

If my maths is right, less than 5% of the people invited to participate returned an intake questionnaire - and presumably not all of those will have done the follow-up surveys - so possibly not very representative of a general population?

 

I guess it's possible that it's real, but social factors also come into it?

Maybe people who report they are very active are more likely to mix in a series of different social groups, and are therefore at higher risk of repeat infections? That alone would raise the risk of Long Covid—and it would actually be true of people who do any group activities in addition to work and family commitments, whether or not they involve much physical effort.

The paper may have accounted for this, though, I get a bit blinded when they're full of numbers.

 

Maybe there is a cognitive bias in that when your exertion is limited by sequelae, you are more likely to view your previous level of exertion as “high”, than someone who had regained the same level of functioning.

 

There is that, but it's also common for people to overestimate their physical activity.

We've probably all known folk who thought they were supremely fit and wore the shiny gym gear to prove it, even though they'd have improved their fitness much more by putting on a tatty fleece and stacking shelves in a supermarket.

 

Apologies, not able to look up the paper myself -- do the authors discuss that as a limitation? Also, does anyone know how that percentage is comparable/ dealt with in similar surveys or can assess how sound the rest of their methodology is?

That certainly is a interesting finding. Almost as interesting as forum members' skepticism ;-)

To add to the latter:

Or maybe people who use to be overproportionately physically active when they are able to also tend to be more active in responding to that kind of surveys/ engage with that kind of inquiries?

 

I've read that people with higher physical activity decondition more than those with lower physical activity in those studies where they purposely decondition people - sorry, don't know which studies. That makes me wonder how they define deconditioning, and how they define more. Anyone know which studies those would be?

Something about regular vigorous exercise might leave you vulnerable to whatever the fatigue process is, by downregulating or upregulating or depleting something or other. We know that in certain genetically-at-risk groups, regular strenuous exercise leads to development of MND/ALS: https://www.sheffield.ac.uk/news/fr...t strenuous exercise,women do not develop MND.

I think it's also possible that attempted resumption of vigorous exercise, which would only be attempted by those with higher pre-morbid physical activity level, directly causes the fatigue process to continue/get worse.

For example, I "recovered" initially from my triggering infection (not COVID), gradually. I was able to work, socialise and do moderate exercise. I then gingerly made my way back towards vigorous exercise over many months, seemed to tolerate it, but within weeks of getting into the genuinely vigorous category I relapsed and got worse for the next 10 years. Could be a coincidence, but I do wonder whether I'd be healthy if I'd just been one of the many people who live perfectly lovely lives without vigorous exercise.

My hunch based on my own experience is yes. Whatever ME/CFS is, I think it was there from the first sign of the triggering infection. Really hope some good prospective long COVID studies might shed light.

Wouldn't it be amazing if we got to a point where a person with post-viral symptoms could have some kind of immunological profile done, like those mentioned by @SNT Gatchaman above, and be told it's either safe or not safe for you to exercise gently/moderately/vigorously, and that actually helped more people be less disabled or even live normal or almost-normal lives?

 

I'm not. This has been anecdotally evident from the start, although it was never clear just how significant, and whether it had much to do with a greater likelihood of fit people reporting their status vs sedentary people. But given how many very fit people had developed LC, it obviously didn't offer much protection at an individual level.

What's more likely to be true is that it's largely irrelevant, and rather it's pre-illness habits of being active that make them more likely to exert themselves when they should be resting, but that applies to all sorts of other factors. People don't have to be physically active in order to lead busy lives. Lots of people never formally do any sport, yet barely ever rest. They'll work a lot, intellectual work for the most part, always busy, never really physically active in a sense that would count as sport.

It's looking more and more like there aren't any actual risk factors and that it's all down to pure chance aside from sex, and even then the ratio is probably badly estimated because of reporting and recording biases. And it could mostly be down mostly to gender roles making it a lot harder for women to take the time to rest. There appears to be a bit of a peak around peak parenting years that could be down to that. It probably doesn't explain it all, but a lot of it.

But for sure there is zero chance that there is ever a level of evidence that will convince fans of psychosomatic models. It's an irrational position and no amount of data gets people out of that. Only personal experience can. We see similar things with conspiracy theories, people who get lost down weird rabbit holes.

 

Another paper today that looked at the differentially expressed genes during acute Covid (this time at day 14) in those that do and don't go on to LC.

Differential Gene Expression in the Upper Respiratory Tract following Acute COVID-19 Infection in Ambulatory Patients That Develop Long COVID (2024, Pathogens)