If you often find yourself biting your nails, tearing out your hair and stabbing a weirdly realistic voodoo doll of your boss, there’s a good chance you’re stressed. Need more proof? This is the first Fitbit Charge to feature an EDA sensor, which monitors how your body responds to stress and offers tips on how to manage it. That’s in addition to 24/7 heart-rate monitoring, an ECG and sleep tracking, plus metrics in the app for breathing rate, skin temperature and SpO2, while built-in GPS lets you track runs and 20 other exercises. Subscribe to Fitbit Premium and it’ll even tell you the best time to pull on your trainers and when you should probably remain horizontal. If you say so, Fitbit. £170 / fitbit.com