GARMIN VIVOSMART 4

$199, garmin.com

When fitness trackers first appeared, many wrote them off as a fad – flimsy rubber step-counters that held about as much long-term appeal as calculator watches. But those cynics clearly underestimated the boffins that build these things, as sports bands have advanced beyond recognition. Garmin’s Vivosmart 3 was a massive hit with fitness freaks thanks to features like all-day stress tracking and a ‘rep counter’ for monitoring bench presses. The US company has upped the ante yet further with the tracker’s fourth edition, adding a blood-oxygen sensor, energy-reserve calculator, a seven-day battery life and water resistance. It’s also slimmer than it used to be, which is handy for comfort, but is also a good omen for its wearers, right?

T3 SAYS: This feature-packed fitness tracker may end up knowing more about your body than you do.