Whoop

Whoop is unusual among fitness wearables: it has no screen, shows no time, and focuses entirely on three metrics — recovery, strain, and sleep. This singular focus has made it the wearable of choice for serious athletes, military operators, and health-obsessed professionals.

Core Metrics

Recovery (0-100%): Measured each morning based on previous night's sleep, heart rate variability (HRV), resting heart rate, and respiratory rate. A green score (67-100%) means your body is recovered and ready for hard training. Red (0-33%) means rest or light activity only.

Strain (0-21): Cardiovascular load measured throughout the day in real time. A strain of 15+ is a hard day; under 10 is recovery-level. Whoop recommends a target strain each day based on your recovery score.

Sleep: Whoop tracks time in REM, light, and deep sleep stages, plus sleep debt. It recommends a target sleep duration based on your strain and recovery goals, and detects sleep quality issues like caffeine interference and room temperature effects.

AI Health Coaching

Whoop's AI analyzes behavioral patterns to surface insights: which behaviors correlate with your best recovery (consistent sleep timing, limited alcohol, cold exposure, meditation), which worsen it, and what your body's trends look like across months.

Journal Feature

Daily behavioral data — alcohol consumption, stress, caffeine, naps, meditation, supplements — gets correlated with recovery scores over time. After 30+ data points, the AI surfaces your personal recovery correlations.

Whoop Coach (AI Chat)

Recent versions include an AI assistant trained on Whoop's health data that answers questions about your trends, explains anomalies, and provides personalized recovery advice.

Subscription Model

Whoop operates on a membership model: $239/year includes the hardware. No upfront device cost — the hardware is provided with membership. Higher tiers include advanced analytics and coach access.