They were also queried about whether they experienced sore throat, tender lymph nodes, headache, muscle aches, joint stiffness, unrefreshing sleep, difficulty concentrating or worsening of symptoms after mild exertion.
In the study, 46% of patients met the criteria for ME/CFS. They were also measured for peak oxygen consumption, production and ventilatory rate and volume.
Eighty-eight percent of the patients showed abnormal breathing patterns or dysfunctional breathing.
Also, patients presented with low CO2 values at rest and with exercise, signifying chronic hyperventilation.
In addition, 58% of patients showed proof of circulatory damage to peak exercise performance from either cardiac dysfunction and/or abnormal pulmonary or peripheral perfusion.
“These findings suggest that in a subgroup of long haulers, hyperventilation and/or dysfunctional breathing may underlie their symptoms," Mancini added. "This is important as these abnormalities may be addressed with breathing exercises or ‘retraining.'"
Read the full study here.