Optimizing exercise testing and rehabilitation strategies for long COVID: a focus on post-exertional malaise, 2026, Fagan, Stein et al

[Dolphin]

https://www.tandfonline.com/doi/full/10.1080/21641846.2026.2627169

Research Article

Optimizing exercise testing and rehabilitation strategies for long COVID: a focus on post-exertional malaise​

Cory Fagan
,
Eleanor Stein
,
Jane Shearer
&
Keely Shaw
Received 21 Apr 2025, Accepted 02 Feb 2026, Published online: 19 Feb 2026

ABSTRACT​

Background​

Fatiguing conditions such as myalgic encephalomyelitis/ chronic fatigue syndrome and post-COVID condition affect millions globally, presenting challenges for diagnosis and management due to their complex, multisystemic nature. Post-exertional malaise (PEM) is a key symptom of fatiguing conditions that involves a severe worsening of symptoms after physical or cognitive exertion.

Objectives​

This theoretical paper proposes a PEM-informed physiological decision-making framework that reconceptualizes PEM as a manifestation of impaired physiological recovery rather than solely a subjective symptom response. Drawing on evidence from serial cardiopulmonary exercise testing, the framework integrates reproducible abnormalities in respiratory variables during exercise as objective indicators of impaired metabolic recovery.

Methods​

The authors synthesize current evidence on the use of serial cardiopulmonary exercise tests to objectively assess physiological markers of PEM across two consecutive days. Protocol recommendations are provided. The framework further outlines how exercise test-derived metrics can be translated into rehabilitation decision-making to guide pacing, intensity limits, and progression while minimizing symptom exacerbation.

Conclusions​

The authors provide an evidence-based approach to activity management aimed at reducing harm, avoiding the push – crash cycle, and supporting functional stability and quality of life in individuals living with fatiguing conditions. When done correctly, exercise testing and therapy can be a safe and valuable tool to enhance recovery and quality of life in individuals living with fatiguing conditions, including those experiencing PEM.
KEYWORDS:

• Cardiopulmonary exercise testing
• chronic fatigue
• anaerobic threshold
• exercise intolerance

 

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Additional information​

Funding​

The authors wish to acknowledge Long COVID Web for its role in supporting the completion of this Research Project. The Long COVID Web is funded by the Canadian Institutes of Health Research (CIHR) - Grant #185352.

Notes on contributors​

Cory Fagan​

Cory Fagan (MSc.) the founder and owner of TCR Sport Lab in Calgary, Alberta, serving the local recreational to competitive athlete. TCR is equipped with an Exercise Physiology Lab, where Cory conducts a variety of exercise-based assessments for both clinical and athletic populations.

Eleanor Stein​

Eleanor Stein (MD) is an assistant clinical professor in the Department of Psychiatry, Cumming School of Medicine. She is retired from clinical practice and offers online education.

Jane Shearer​

Jane Shearer (PhD) is a professor at the University of Calgary with appointments in the Faculty of Kinesiology and the Cumming School of Medicine, Department of Biochemistry & Molecular Biology. The overarching theme over their research is metabolic physiology, the knowledge of nutrition and metabolism to help predict, prevent, and treat chronic metabolic diseases. Additional interests including the gut – brain axis and dietary therapies for neurological disorders.

Keely Shaw​

Keely Shaw (PhD) is a postdoctoral associate at the University of Calgary, working in both the Faculty of Kinesiology and the Cumming School of Medicine, Department of Biochemistry & Molecular Biology. Their research investigates the interplay between physical activity and nutrition in optimizing health and physical function in diverse populations.

 

[InitialConditions]

Eleanor Stein is somewhat adjacent to the mind–body and recovery grift stuff on YouTube, so I would treat this with caution.

 

[Jonathan Edwards]

It is fairly obviously pretend science anyway.

 

[Felis Catus]

Eleanor Stein is somewhat adjacent to the mind–body and recovery grift stuff on YouTube, so I would treat this with caution.

She sells her brain retraining programme, too.

Dr. Eleanor Stein MD Online Education

Expert help and resources with ME/CFS, FM and ES (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, Fibromyalgia, Environmental Sensitivities, Long COVID and Chronic Pain)

www.eleanorsteinmd.ca

 

[rvallee]

The authors provide an evidence-based approach to activity management aimed at reducing harm, avoiding the push – crash cycle, and supporting functional stability and quality of life in individuals living with fatiguing conditions

This doesn't work in most cases for the same reason that having a daily budget that goes from -$10 to $1 is not viable in a country where the poverty line is closer to $50/day. As is tradition, they are wildly underestimating the level of disability involved here. Even considering exercise, which is not needed here, when people struggle with activities of daily living makes exactly as much sense as dealing with the constraints of a -$10 to $1 daily budget by browsing a feng shui catalogue for the perfect fountain to, uh, atune the chakra flows, or whatever.

When done correctly, exercise testing and therapy can be a safe and valuable tool to enhance recovery and quality of life in individuals living with fatiguing conditions, including those experiencing PEM.

It's been 6 years of LC, and decades of ME/CFS before that, and this has never panned out. This is still all about establishing the validity of the model, there is nothing being 'optimized' here. Might as well talking about taking out a standard ruler when you're half-way around the world from your destination and you still have no idea which continent it's even on.

 

[Turtle]

She sells her brain retraining programme, too.

Dr. Eleanor Stein MD Online Education

Expert help and resources with ME/CFS, FM and ES (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, Fibromyalgia, Environmental Sensitivities, Long COVID and Chronic Pain)

www.eleanorsteinmd.ca

My brainfog would not get me past "She sells her brain". Maybe the full statement on its own?
Why oh why exercise when there are chores plenty on the to do list.