From Health Rising, an article about CPET testing by Caroline Christian.
It has useful definitions and links.
It has useful definitions and links.
One of the only tests that shows the disability experienced in ME/CFS is the 2-day cardiopulmonary exercise test (CPET). The CPET directly measures an individual’s capacity for work and is considered the gold standard for measuring disability – not only for ME/CFS but for a variety of other conditions. A second day of testing is needed for ME/CFS patients because it is the only way to demonstrate the unique impairments underlying the disease.