NSDR (Non-Sleep Deep Rest)
A 10–20 minute parasympathetic protocol popularized by Huberman Lab. Reduces sympathetic tone and resting BP acutely; chronic effect is suggestive but less well-quantified.
NSDR draws from the yoga nidra and body-scan literature. Acute parasympathetic effects (HRV, resting HR, cortisol) are well-replicated; chronic resting-BP effects are inferred from related interventions (meditation, slow breathing).
NSDR is a category of practice rather than a single technique. The shared structure: lie down, body scan, slow breathing (often 4-second inhale / 6–8 second exhale), 10–20 minutes. It is not sleep — it is deliberate parasympathetic activation.
Why it's in the protocol
Two reasons. First, the acute effect on BP and HRV is well-documented for related practices (yoga nidra, meditation, slow paced breathing). Second, late-afternoon NSDR seems to dose-shift sleep quality at night, which is itself a lever for resting BP.
The evidence base for NSDR specifically (as branded) is thin. The evidence base for what NSDR borrows from is stronger.
How it sits in the stack
Week 2. Comes in after the foundation is established. Late afternoon (3–5 PM) is the highest-leverage time slot.
Practical notes
The app includes a guided NSDR session. Headphones, dim room, supine position. Many users find it works best on days following heavy training.