Non-invasive Treatment for Long COVID (Post COVID-19 Condition) Brain Fog

Inclusion criteria:

* English speaking
* Diagnosis of Long COVID

Exclusion criteria:

* Any history of:

  * Coronary artery dissection or aortic dissection
  * Neurological disease (e.g. dementia, Alzheimer's disease, or other brain-related disease)
  * Cerebrovascular disease or stroke
  * Aneurysm
* If currently has:

  * Moderate-severe chronic obstructive pulmonary disease
  * Uncontrolled moderate-severe asthma
  * Moderate-severe bronchiectasis
  * Moderate-severe interstitial lung disease, requiring the use of supplemental oxygen
  * A necessity to use supplemental oxygen, for any reason
  * New or worsening symptoms (decompensation) of heart failure
  * Right heart disease due to chronic pulmonary disease/sleep apnea
  * Uncontrolled myocardial ischemia or angina
  * Uncontrolled heart arrhythmias
  * Heart or lung infection (e.g. myocarditis or pericarditis)
  * Left main coronary artery stenosis
  * Moderate-severe aortic stenosis
  * Pulmonary embolism, pulmonary infarction, or other blood clots
  * Severe respiratory disease
  * Chronic kidney disease
  * Chronic liver disease
* Females of childbearing potential will complete a urine pregnancy test at their baseline visit to rule out pregnancy
* BMI \>40
* Study staff unable to obtain adequate signal for cerebral blood flow