Enhanced External Counterpulsation to Treat Long COVID-19 Fatigue

The goal of this double blind, outcome-assessor blind, randomized controlled trial, is to compare the effectiveness of external encounter counterpulsation (EECP) versus sham procedure in participants with long COVID-19 fatigue. The main question\[s\] it aims to answer are: * Whether EECP improves fatigue score * Whether EECP improves quality of life, six-minute walk test, and endothelial function Participants will attend 15 sessions (1-hour each) of EECP during 5 weeks Researchers will compare EECP versus sham procedure for the above outcomes.