sjalf

physiological

Physiological

Garmin-based tracking of HRV, RHR, sleep, stress, and physiological patterns

March 9, 2026

Approach

Continuous biometric tracking via a Garmin watch, informed by the framework from The Pulse Cure. The goal is to build awareness of autonomic nervous system patterns and use that data to make better decisions about recovery, stress management, and training.

Metrics Tracked

  • HRV (Heart Rate Variability): primary indicator of autonomic nervous system balance and recovery status
  • RHR (Resting Heart Rate): baseline cardiovascular fitness and recovery trending
  • Body Battery: Garmin’s composite energy metric combining HRV, stress, activity, and sleep
  • Sleep Score: sleep quality and duration tracking
  • Autonomic Stress: overall stress values throughout the day
  • Runs: tracked via Garmin for pace, heart rate zones, and training load

Observations

Intermittent Fasting and Stress

Fasting in the morning until noon produces a very low stress window on the Garmin. It’s unclear whether this reflects genuinely low physiological stress or is an artifact of reduced metabolic activity (digestion itself is a stressor the watch may be detecting). Regardless of the mechanism, the pattern is consistent enough to be useful. Fasting until noon is used as a tool to reduce measured stress on days following poor sleep.

Sleep as a Lever

Poor sleep shows up clearly in next-day HRV and body battery. When sleep scores are low, downstream decisions shift: lighter training, fasting until noon, reduced cognitive load where possible. The biometrics make the cost of bad sleep concrete and visible rather than just a feeling.

Supplementation

Evening: Sleep & Stress

  • Magnolia bark: GABAergic, reduces cortisol, promotes sleep onset
  • Magnesium: muscle relaxation, nervous system calming, sleep quality
  • Passionflower: anxiolytic, supports sleep without next-day grogginess

Morning: Energy & Health

  • Lemon balm: calming without sedation, mild cognitive support
  • Ashwagandha tea: adaptogen for stress modulation (used sometimes, not daily)
  • Omega-3 krill oil: anti-inflammatory, cardiovascular and cognitive support. Krill over fish oil for lower mercury exposure.
  • DIM (Diindolylmethane): estrogen metabolism support
  • Zinc: immune system support
  • Vitamin D: baseline supplementation for immune function and mood
  • Rhodiola Rosea: mitochondrial adaptogen for energy (used sometimes, not daily)