There’s a good reason people don’t tend to go running in one of those old-fashioned diving suits or a pair of steel toe-capped boots: weight. When you’re chasing a 10K PB or just trying to finish a marathon, chances are you’ll take every opportunity to shed any unwanted extra grammes. If that’s you, the new Coros Pace 2 (£180) could be the running watch for you. At just 29g, Coros reckons it’s the lightest GPS watch on the planet, but when it comes to features it’s anything but lightweight. The Pace 2 is waterproof, has a heart-rate monitor, a special track mode and Strength Training for over 200 exercises, plus all the usual notification stuff you’d expect from a regular smartwatch. In that mode you’ll get 20 days between charges, or 30 hours of continuous GPS use. Now all you need is a similarly slimline diving suit.