Before you can use the recovery time feature, you must have a Garmin^® device with wrist-based heart rate or a compatible chest heart rate monitor paired with your device (Pairing Your Wireless Sensors). If your device was packaged with a heart rate monitor, the device and sensor are already paired. For the most accurate estimate, complete the user profile setup (Setting Up Your User Profile), and set your maximum heart rate (Setting Your Heart Rate Zones).