Positives

• A patient reported that several days of low HRV reliably signaled a need to rest and helped them avoid PEM crashes Mark Wells.
  
  
• Clinicians describe HRV as the most useful Whoop metric for guiding pacing decisions in Long COVID rehab Cornerstone Physio.
  
  

Negatives

• A patient stopped tracking heart rate altogether because the data introduced anxiety and worsened their symptoms Mark Wells.
  
  
• A patient noted HRV readings did not correlate well with how they actually felt day-to-day Science for ME.
  
  

Hurdles & Side Effects

• Patients face a mandatory monthly subscription on top of the band, which compounds for years of pacing use Michael Kummer.
  
  
• A patient noted accuracy limitations during low-activity Long COVID days when readings drift Marco Altini.