Answered from WHOOP CEO, Will Ahmed: 50B Hours of Health Data, a 4 Million Member Data Moat, & the FDA Fight · All-In with Chamath, Jason, Sacks & Friedberg · 2026-10-29
Will Ahmed describes heart rate variability as the variation in time between successive heartbeats, where more variability generally means the body is regulating well. It reflects the balance between sympathetic activity, which raises heart rate and blood pressure, and parasympathetic activity, which lowers them. WHOOP measures it around the clock, baselines each member and uses it for the recovery and stress scores. Ahmed says HRV tends to fall with age, so holding a high number later in life is a sign of fitness and longevity.
Source: our own transcription of the episode. The full conversation is on All-In with Chamath, Jason, Sacks & Friedberg (2026-10-29). Read the whole episode summary →