As well as encouraging you to stand regularly and be more active, the new Apple Watch has some smart features that can keep your body healthy in other ways too. The ECG measures using electrodes built into the digital crown and the back crystal on your wrist, and it can classify if the heart is beating in the normal pattern, or if there are signs of atrial fibrillation – a heart condition that causes irregular, often abnormally fast heart rates. The Watch will also know if you’ve taken a hard, unexpected fall by analysing your wrist’s trajectory. If you don’t respond within 60 seconds of the fall notification, the Watch will automatically call the emergency services so they can get to you and help. If there’s ever been a watch that’s more concerned about your health, we haven’t seen it.