Neural Mechanisms of Fatigue in Post-Acute Sequela of SARS-CoV-2

Inclusion Criteria: * Age 18 to 75 years old. * Have received a clinical diagnosis of post-acute sequelae of SARS-CoV-2 (PASC)/long COVID syndrome using the criteria specified by Thaweethai, et al., 2023 (JAMA). This symptom checklist provides a score based on the number and severity of symptoms. An individual with a score \>12 is classified as having PASC. * Currently experiencing Fatigue/Brain Fog as assessed with the Post-COVID symptom checklist and the PedsQL questionnaire. Exclusion Criteria: * Neurological disorders including, but not limited to, stroke, head injury, epilepsy, seizures, brain tumors, brain surgery, Parkinson's Disease, or any other neuromuscular disease (self-report). * Diagnosed history of severe psychiatric diseases such as depression and schizophrenia (self-report). * Congestive heart failure. * Peripheral artery disease with claudication. * Cancer. * Pulmonary or renal failure. * Unstable angina. * Uncontrolled hypertension (more than 190/110 mmHg). * Severe aphasia. * Orthopedic or pain conditions. * Have had exposure to metal or metal implants, due to the hazardous effects of the magnetic field. * If on immunomodulatory therapy, they must have been on that therapy for at least 6 months before the start of the study. Healthy age- and sex-matched controls for PASC - Exclusion criteria: Participants with a history of any of the following will be excluded from the study: * Hospitalization due to SARS-CoV-2 infection. * Neurological disorders including, but not limited to, stroke, head injury, epilepsy, seizures, brain tumors, brain surgery, Parkinson's Disease, or any other neuromuscular disease (self-report). * Diagnosed history of severe psychiatric diseases such as depression and schizophrenia (self-report). * Congestive heart failure. * Peripheral artery disease with claudication.