The Whoop 5.0 is a fitness band you wear on your wrist, while the Oura Ring 4 is a smart ring for your finger. This obvious difference makes the Whoop 5.0 easier to buy, as there’s no sizing required.

The appeal of a screenless device is simple: comfort and discretion. Many users find Garmin’s bulkier multisport watches uncomfortable to wear overnight, especially for sleep tracking. A compact ...