Resting Heart Rate, HRV & Knowing When to Take Off the Watch
Reflections from both sides of the sensor—working in MedTech strategy by day while training with optical and chest-strap biometrics.
Spend enough time studying clinical-grade biosensors at work and wearing GPS watches and smart rings outside of work, and you develop both deep admiration and healthy skepticism for consumer algorithms. Photoplethysmography (PPG) LEDs on a wrist or finger have come remarkably far at capturing resting heart rate trends, skin temperature shifts, and overnight heart rate variability.
Directional Trends vs. Single-Morning Noise
Where consumer wearables shine is longitudinal context: spotting the subtle 4 bpm elevation in resting heart rate forty-eight hours before a viral cold hits, or seeing how a red-eye flight from SFO to BOS flattens parasympathetic recovery for three nights. Where they stumble is turning noisy single-night estimates into a single authoritative “readiness” grade before you have even checked in with your own legs.
“The best athletes—and the best clinicians—treat biometric telemetry as a second opinion, never a substitute for interoception.”
During hard interval blocks I still swear by an ECG chest strap because wrist optical sensors lag during rapid cadence spikes and cold-weather vasoconstriction. And on vacation hikes? Leaving the watch screen flipped to plain time-of-day remains one of my favorite luxuries.