Gadget Review: TomTom Runner 3 fitness tracker

Ease of use: 4/5

A few niggly things such as the watch going back to "demo" mode whenever it's charged, so you have to reset it every time.

Efficacy: 5/5

It does what it's meant to do. It records runs perfectly, with accurate GPS mapping. The built-in heart rate monitor is accurate.

Calorie burn: 5/5

Deadly accurate, and not just on a run. Because it tracks heart rate so accurately, it means that the calorie burn readings are pretty good.

Improvements: 4/5

It's a bit fragile.