No Pulse Oximeter
Most new smartwatches on the market include a pulse oximeter. Even Garmin’s low-end fitness bands can measure blood oxygen levels. Despite all that it can do, the Apple Watch Series 5 still lacks this critical sensor. Blood oxygen is an important metric that you can use to track your fitness level and sleep quality. If pulse ox is a must-have, you should wait to purchase the Apple Watch Series 6, which is rumored to ship with an onboard SpO2 sensor.