Our Take
The Whoop 4.0 is a screenless, subscription-based fitness and recovery tracker aimed at serious athletes and dedicated gym-goers who want continuous, granular health data rather than smartwatch convenience. It competes with Garmin and Oura in the performance-monitoring space, distinguishing itself through its focus on recovery scoring, strain tracking, and round-the-clock physiological monitoring without the distraction of a display.
Key Features
Continuous heart rate, heart rate variability (HRV), skin temperature, and blood oxygen monitoring
Proprietary "Recovery Score" calculated each morning based on HRV, resting heart rate, and sleep quality
"Strain Coach" that recommends daily exertion levels based on your recovery data
Sleep tracking with automatic sleep and wake detection, plus sleep-need calculation
Screenless, notification-free design worn on the wrist or via optional body-site accessories (bicep, chest, waistband)
Waterproof build suitable for swimming; battery life of roughly four to five days
Our Verdict
The Whoop 4.0 suits committed athletes — runners, CrossFitters, competitive sports players — who want deep recovery insight and are willing to pay a recurring fee for it. If you're a casual gym-goer, find subscription models frustrating, or want an all-in-one smartwatch, look at a Garmin or Apple Watch instead.