Product Price Heart Rate Monitor Step Counter Calories Burned Sleep Tracking Activity Tracking Battery Life (hours) Waterproof Rating
Whoop Whoop 4.0 (with monthly membership)
US
£22.42 Yes (accelerometer-based step tracking) Yes (strain and saved activities with heart rate zones) 4 to 5 days Water resistant up to 10 meters for 2 hours

WHOOP 4.0 is a screen-free wearable focused on 24/7 biometric monitoring including continuous heart rate, HRV, sleep, steps, and strain with app-based personalized insights; it uses on-wrist charging and removable battery packs and requires a membership. It suits athletes and committed users who want deep recovery and sleep analytics without smartwatch distractions.

★ Ideal for

Best for minimizing charging frequency compared with earlier WHOOP models because it offers 4 to 5 days battery life (reducing charging to roughly twice per week).