Summary
High altitude acutely reduces HRV through vagal withdrawal and sympathetic activation. This effect is more pronounced above 3,500m and diminishes with acclimatization over days to weeks.
Methods
Systematic review and meta-analysis of altitude HRV studies
Key Findings
- Acute altitude markedly reduces time and frequency domain HRV
- LF/HF ratio increases (sympathetic predominance)
- Effects more pronounced above 3,500m
- Trained individuals show better vagal preservation
- Gradual ascent helps maintain autonomic balance
Limitations
Individual acclimatization rates vary significantly
What This Means for You
Expect lower HRV when traveling to altitude. Allow 3-5 days for initial acclimatization before judging your HRV. Gradual ascent and maintaining breathing rhythm can help.
Source
Read the original paper in Frontiers in Physiology ↗
Added to HRV Zone: 2025-01-10