02/14/2026
๐ฃ๐ผ๐๐-๐ฒ๐
๐ฒ๐ฟ๐๐ถ๐ผ๐ป๐ฎ๐น ๐บ๐ฎ๐น๐ฎ๐ถ๐๐ฒ (๐ฃ๐๐ ) ๐ฎ๐ป๐ฑ ๐๐ต๐ฒ ๐บ๐๐๐ต ๐ผ๐ณ ๐ฐ๐ฎ๐ฟ๐ฑ๐ถ๐ฎ๐ฐ ๐ฑ๐ฒ๐ฐ๐ผ๐ป๐ฑ๐ถ๐๐ถ๐ผ๐ป๐ถ๐ป๐ด: ๐ฟ๐ฒ๐๐ต๐ถ๐ป๐ธ๐ถ๐ป๐ด ๐๐ต๐ฒ ๐ฝ๐ฎ๐๐ต๐ผ๐ฝ๐ต๐๐๐ถ๐ผ๐น๐ผ๐ด๐ ๐ผ๐ณ ๐น๐ผ๐ป๐ด ๐ฐ๐ผ๐๐ถ๐ฑ
PEM is a hallmark feature of long COVID, affecting approximately 80% of patients (https://pubmed.ncbi.nlm.nih.gov/39694730/ ). It is characterized by a delayed exacerbation of symptoms following physical or cognitive activity that exceeds a patient's specific, often narrow, threshold. Crucially, these "crashes" are not merely temporary fatigue; they can persist for weeks or even result in a permanent decline in the patient's baseline health. Because of this risk, major health authorities like the WHO have cautioned against traditional graded exercise therapies for these individuals (https://www.who.int/publications/i/item/WHO-2019-nCoV-clinical-2023.2).
๐In a brand-new publication, Charlton and colleagues (https://bjsm.bmj.com/content/early/2026/02/09/bjsports-2025-111387) debunk the deconditioning myth of long covid. While physical inactivity (deconditioning) can occur in chronically ill patients, the authors present evidence that it cannot explain the specific cardiac alterations seen in long COVID:
โ
Preload Failure: Many patients suffer from "preload failure," where the heart does not fill with enough bloodโa phenomenon not typical of simple deconditioning.
โ
Structural and Inflammatory Changes: Research has identified myocardial scarring, inflammation, and "leaky" blood vessels in long COVID cohorts.
โ
Mitochondrial Dysfunction: There is significant evidence of deranged mitochondria and impaired oxygen extraction at the cellular level, suggesting an energy production failure rather than just a lack of fitness.
๐ซ A Human-Centered Approach to Rehabilitation
The authors emphasize that because long COVID is highly heterogeneous, treatment must be personalized and data-driven. They advocate for several specific strategies:
โถ๏ธ Systematic Screening: Healthcare providers should use tools like the DePaul Symptom Questionnaire to identify PEM early and distinguish it from other pathologies.
โถ๏ธ Heart Rate Pacing: Utilizing wearable monitors to stay within the "first ventilatory threshold" allows patients to remain within their "energy envelope," preventing the repetitive exposure to PEM events that can worsen their health.
โถ๏ธ Postural Management: For those with POTS or severe PEM, gentle upright postures, supported sitting, and compression garments are recommended to prevent skeletal muscle decline without triggering a crash.
โถ๏ธ Targeted Pharmacotherapy: The use of low-dose naltrexone, beta-blockers, or pyridostigmine may be necessary to reduce the symptom burden of PEM and autonomic dysfunction.
๐กUltimately, the paper concludes that cardiac alterations in long COVID are largely independent of deconditioning, and safe recovery requires moving away from historical exercise guidelines toward an individually tailored management strategy.