[1][2] PEM is a cardinal symptom of myalgic encephalomyelitis/chronic fatigue syndrome and is common in long COVID as well.

[6] A 2-day CPET can objectively measure PEM and its effect on physical functioning.

[4] While it should not be required for a diagnosis, a 2-day CPET can show that symptoms are not due to deconditioning and provide evidence for obtaining disability benefits.

[7] Because PEM is also a symptom of long COVID, the 2-day CPET may be useful in evaluating exercise intolerance there as well.

[3] The test provokes symptoms by design, and recovery may be prolonged.