Summary
Meta-analysis of 11 randomized controlled trials confirms that sleep deprivation causes significant decreases in parasympathetic HRV markers and increases in sympathetic activation.
Methods
Systematic review and meta-analysis of 11 RCTs with 549 participants
Key Findings
- RMSSD significantly decreased after sleep deprivation (p < 0.05)
- LF power significantly increased (sympathetic activation)
- LF/HF ratio significantly increased after sleep loss
- Effects consistent across different sleep deprivation protocols
Limitations
Heterogeneous study designs, mostly acute sleep deprivation
What This Means for You
Even one night of poor sleep measurably shifts your nervous system toward sympathetic dominance. This explains why your HRV drops after bad sleep and why sleep is the foundation of HRV optimization.
Source
Read the original paper in Frontiers in Neurology ↗
Added to HRV Zone: 2026-01-21