Movement is medicine in most chronic conditions. After a heart attack, after cancer treatment, after major surgery, the evidence for progressive exercise rehabilitation is strong and consistent. Long COVID is the exception. A substantial proportion of long COVID patients, particularly those with post-exertional malaise, experience worsening of their symptoms when they attempt the kind of incremental exercise progression that would benefit most other conditions. Understanding why this happens, and what movement approaches are therefore appropriate, is one of the most important practical questions in long COVID management.
Why Standard Exercise Recommendations Do Not Apply
Post-exertional malaise, a hallmark feature of long COVID shared with myalgic encephalomyelitis and chronic fatigue syndrome, is not simply being tired after exercise. It involves a delayed systemic worsening of symptoms, typically peaking 12 to 48 hours after exertion, that can include significantly increased fatigue, cognitive impairment, pain, and autonomic symptoms. Research published in Nature Communications in 2021 found that long COVID patients with post-exertional malaise showed immune and metabolic abnormalities after a standardised exercise challenge that were not seen in healthy controls or in COVID-recovered individuals without persistent symptoms.
Graded exercise therapy, which involves systematically increasing exercise duration and intensity over time, was previously recommended for chronic fatigue syndrome and was included in early NHS guidance on long COVID. This recommendation has been significantly revised following patient evidence and the results of the PACE trial re-analysis. NHS England's current guidance explicitly states that graded exercise therapy should not be used for those with post-exertional malaise and that pacing should be the primary approach.
The Pacing Principle
Pacing is the practice of staying within one's energy envelope, meaning the level of activity that can be sustained without triggering post-exertional malaise. For many long COVID patients, this means activity levels far below what they were capable of before illness. The concept of the energy envelope was initially developed in the chronic fatigue syndrome community and is now being applied widely in long COVID rehabilitation. The practical implementation involves identifying one's current threshold through careful activity monitoring, staying consistently below it, and allowing stabilisation before any incremental increase.
Heart Rate Monitoring as a Practical Tool
Many long COVID physiotherapists recommend heart rate monitoring to provide an objective boundary for activity. A commonly used threshold is 60 percent of maximum heart rate, or a heart rate of approximately 100 beats per minute for most adults, which correlates with the anaerobic threshold in deconditioned individuals. Staying below this threshold avoids the metabolic demands that appear to trigger post-exertional malaise in susceptible patients. Wearable devices that provide continuous heart rate monitoring make this approach practically accessible.
Movement Types That Are Appropriate
- Gentle walking at conversational pace: the aim is to stay well below the anaerobic threshold; start with 5 to 10 minutes if needed and only extend when stable over several days
- Seated stretching and range of motion exercises: maintain joint mobility and reduce deconditioning without cardiovascular demand
- Breathing exercises: diaphragmatic breathing and pursed-lip breathing improve breathlessness and reduce the work of breathing; these are low-demand and actively therapeutic
- Yoga Nidra and restorative yoga: the evidence for restorative yoga in post-viral fatigue is limited but it has strong biological plausibility given its activation of the parasympathetic nervous system; it is appropriate as a form of active rest
- Aquatic therapy: warm water reduces the cardiovascular demand of movement through hydrostatic pressure effects on venous pooling, which is particularly helpful in dysautonomia; water buoyancy reduces the musculoskeletal load of movement
- Tai chi: a systematic review in PLOS One in 2020 found that tai chi significantly improved fatigue, quality of life, and sleep in patients with chronic fatigue conditions; its low-intensity, rhythmic nature keeps heart rate well below the post-exertional malaise threshold
When to Seek Specialist Rehabilitation
NHS long COVID clinics offer multidisciplinary assessment including physiotherapy input. Those with significant breathlessness, cardiovascular symptoms, or post-exertional malaise that is affecting their ability to carry out daily activities should be assessed before embarking on self-directed exercise programmes. The COVID-19 Physiotherapy Guidance published by the Association of Chartered Physiotherapists in Respiratory Care provides a structured framework that has been widely adopted by NHS services.
Sources
- Twomey, R., et al. (2022). Postexertional malaise in people living with long COVID. Journal of Clinical Medicine, 11(23), 6952.
- Greenhalgh, T., et al. (2022). Long COVID: a national response effort. BMJ, 376, n2914.
- Wong, T.L., & Weitzer, D.J. (2021). Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome: a systemic review and comparison of clinical presentation and symptomatology. Medicina, 57(5), 418.
- NHS England. (2023). Long COVID guidance on rehabilitation. NHS England official guidance.
- Jimeno-Almazan, A., et al. (2021). Post-COVID-19 syndrome and the potential benefits of exercise. International Journal of Environmental Research and Public Health, 18(10), 5329.