Respect for persons, beneficence, and justice are bedrock ethical principles in science. They are especially important when studying vulnerable populations. Billias et al. argue that deception is necessary to assure the internal validity of their exercise study involving people living with long COVID.[1] Here, we assert the use of deception is ethically indefensible and scientifically unnecessary in this population. It undermines informed consent, increases risks for harms, exploits the vulnerability of participants, and erodes trust in science and health care, all while exploring a question that already has been asked and answered satisfactorily enough to inform clinical recommendations.
Physical activity is a common trigger for post-exertional malaise (PEM),[2 3] which is common in people living with long COVID.[4] PEM involves an impaired recovery response from exertion that is distinct from deconditioning. [5 6] The hallmark of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is PEM. Exercise is no longer recommended in contemporary clinical guidance for ME/CFS, because an accumulation of evidence from research and lived experience suggests it is likely to cause avoidable harms.[7] Exercise prescription without adequate safeguards for PEM even may be considered negligent practice. The protocol acknowledges people living with PEM often worsen with exercise dosages that may be appropriate for other conditions.