Summary
Major scoping review concluded that the LF/HF ratio should not be used as a marker of sympathetic/parasympathetic balance. The ratio is influenced by too many factors to reflect autonomic tone reliably.
Methods
Scoping review of HRV methodology literature
Key Findings
- LF power reflects both sympathetic and parasympathetic activity
- Breathing rate significantly affects LF/HF independent of autonomic state
- No consensus on interpretation standards
- RMSSD and HF power are more reliable parasympathetic markers
Limitations
Some researchers still defend LF/HF utility in specific contexts
What This Means for You
If your app or device reports LF/HF ratio, take it with a grain of salt. Focus on RMSSD or HF power for parasympathetic (recovery) assessment. The scientific community has largely moved away from LF/HF interpretation.
Source
Read the original paper in Frontiers in Physiology ↗
Added to HRV Zone: 2025-01-07