Our latest work now posted as a pre-print on @researchsquare: "ME/CFS and Long COVID Demonstrate Similar Bioenergetic Impairment and Recovery Failure on Two-Day Cardiopulmonary Exercise Testing" @4Workwell researchsquare.com/article/rs-860…
Using two‑day cardiopulmonary exercise testing (CPET), we compared physiological responses in people living with #MECFS and #LongCovid with matched controls, stratifying by sex, to resolve the weaknesses of single tests in mixed-sex cohorts we've seen so far in CPET studies.
The primary studies comparing #MECFS and controls already have been published. You may recognize them from work often discussed here. The data is available from mapmecfs.org.
📌 Hansen et al 2024: pubmed.ncbi.nlm.nih.gov/38232699/
📌 Keller et al 2024: pubmed.ncbi.nlm.nih.gov/38965566/
Here's what we learned:
👉 Both ME/CFS and Long COVID show similar failure to recover after exertion
👉 Largest impairments occur at the ventilatory anaerobic threshold, suggesting similar aerobic system impairments between ME/CFS and Long COVID
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👉 Females exhibited more pronounced post‑exertional CPET abnormalities than males, but were present in both sexes
👉 No meaningful differences were observed between ME/CFS and Long COVID on two-day CPET, suggesting they share a common bioenergetic pathophysiology
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👉 Severe functional impairment was common in both patient groups and was not explained by effort preference, deconditioning, ventilation, or hemodynamics
Maybe the most remarkable thing? We didn't purposefully select for a cohort with Post COVID ME. It was dealer's choice.
Normally you might expect noisy case definitions to wash out any effects, because as we know, Long COVID isn't just one thing. But, at least in our sample, it didn't seem to matter. CPET responses were statistically and functionally similar between ME/CFS and Long COVID anyway.
These results reinforce post‑exertional malaise (PEM) is a measurable physiological phenomenon. In an era where the 'lazy-crazy dichotomy' still gets pushed as explanations for ME/CFS and Long Covid, unfortunately this doesn't get to be a throwaway line yet.
It still matters.
The findings of this study also underscore the value of two‑day CPET as a useful tool to:
✅ Differentiate PEM from normal recovery using objective measures
✅ Inform disability evaluations in people who can and choose to have a CPET
✅ Improve precision in clinical trials
Anyway, thanks for reading. I'm grateful to my co‑authors and to the patients. Their generous engagement continues to advance our understanding of these terribly disabling yet largely ignored chronic conditions.
Mechanistic work is slow but worth it. More forthcoming. Onward.
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