What is the threshold over which PEM is induced in chronic illness? This is a hugely important question for sufferers, and one for which Rob Wüst is trying to find an answer. Assistant Professor in Musculoskeletal Health and Physiology at the Vrije Universiteit Amsterdam, Dr. Rob Wüst is able to see the physiological impact of Long Covid and ME/CFS in skeletal muscle abnormalities. In his latest study (currently in preprint) he finds that “Skeletal muscle properties in long COVID and ME/CFS differ from those induced by bed rest”,  and the abnormalities that he observes in the muscles of this cohort of patients correlate with the Post-Exertional Malaise (PEM), autonomic dysfunction and wearable data that he gathered in another recent study. In this week’s episode Wüst explains to Emily Kate Stephens how he observed exercise-induced worsening of symptoms in almost half of Long Covid patients when they exceeded their ‘ventilatory threshold’ but the much of the time this is from everyday activities such as hanging the laundry or carrying the groceries.  But they discus He discusses the physiological clues emerging from exercise testing and muscle biopsies in patients when viewed alongside wearable data and expounds on the circulating theories on this, including mitochondrial dysfunction, local hypoxia, and ion channel abnormalities.  And he explores the parallels and distinctions between Long Covid and ME/CFS and why interdisciplinary collaboration is vital to unlock these complex, multi-systemic diseases. The Impact of Bedrest Study 2024 Skeletal muscle adaptations and PEM in LC 2024 Should we be careful with exercise in PEM in LC? 2025 Make Visible @visible_health @visible.health