GPS is a must for any self-respecting fitness tracker designed for people who are after a bit more than just a reminder of how sedentary they are. If you've only ever heard of GPS in your car's sat-nav, here's a quick run-down.
For bonus points, we'll also take GLONASS support. This is the same sort of thing, but where GPS uses a system of 'at least 24' US satellites, GLONASS uses another 24 Russian satellites as well – so you double your chances of success, to put it in simple terms.
Surprisingly, few fitness trackers actually use GPS, because it eats battery like it's discount chocolate and is likely to get under-informed people upset, as it can take a little while to 'lock on' to the signal.
Almost all good runners' watches have GPS, but so do the Fitbit Surge, the Garmin Vivoactive, the Microsoft Band 2, the Motorola Moto 360 Sport and Sony SmartWatch 3.
We want more, though, particularly in smaller devices. The key to that? The new battery tech we've already talked about.
