GARMIN ENDURO

With a battery lasting up to 80 hours in GPS mode, we know how Garmin’s Enduro gets its name. Like a lot of other sports watches it measures VO2 Max, but the Enduro also takes altitude and terrain into account to give trail runners accurate readings, while the enhanced Climbpro mode helps you to pace yourself through all the ups and downs. The 1.4in display is covered in light-harvesting Power Glass, so you can turn off GPS and switch to smartwatch mode to bump up the battery life to 65 days, or even eke out an entire year in basic watch mode… although that would mean missing out on heart-rate tracking, Pulse Ox and sleep monitoring. Making it, well, just a watch. from £700 / garmin.com