Chronic Fatigue and the Autonomic System
Chronic fatigue conditions—including Chronic Fatigue Syndrome (CFS/ME), long COVID, and other persistent fatigue states—are characterized by autonomic dysfunction. HRV provides a window into this dysfunction and can help guide activity management.
Important note: If you're experiencing persistent fatigue, work with healthcare providers. HRV is a monitoring tool, not a diagnostic or treatment solution.
HRV Patterns in Chronic Fatigue
Common findings: - Lower baseline HRV than healthy controls - Exaggerated HRV drop after exertion - Prolonged recovery from normal activities - Blunted HRV response to interventions - Higher resting heart rate
Post-exertional malaise (PEM): - HRV crash 24-72 hours after overexertion - Can last days to weeks - Pattern often visible before symptoms peak - Key to activity management
Using HRV for Pacing
For people with chronic fatigue, HRV is most valuable for pacing—staying within your "energy envelope" to avoid crashes.
Daily pacing: - Check HRV before planning activities - Lower than baseline → reduce planned activity - Significantly below baseline → rest priority - Don't push on low HRV days
Activity planning: - Track which activities cause HRV crashes - Note the delay (often 24-48 hours) - Build a personal activity tolerance map - Scale activities to HRV status
Related Guides
- Low HRV — Understanding chronically low HRV
- HRV Illness Recovery — Monitoring during recovery
- HRV and Breathing — Gentle breathing techniques