Price: £100 | Check price on Amazon.co.uk
If you don't have a fitness tracker, the Fitbit Alta HR (£100) is a great place to start. Unlike a smartwatch, the battery lasts a whole week and the slim and discreet band houses plenty of tech. It tracks steps, calories burned, sleep and heart rate and comes in six colours. The only downside is it's not waterproof.
If you're ready for something more serious, or want a tracker for specific activities like swimming, read the WIRED Recommends guide to the best fitness trackers.