signals travel (the speed of light – it does 10K in 1/30000th of a second) the GPS receiver can work out how far it is from each satellite. The receiver then plugs those numbers into some very complicated calculations to work out its position on the Earth

zone at the back of the shoe from the rest of the sole unit. This design improves a shoe's shock-absorption capabilities by reducing the impact forces travelling from the heel to the rest of the outsole and midsole. The latest running shoes achieve

in the most unpredictable ‘great British summer’.We’re on hand with some easy tips to make sure your kit works hard from head to toe, keeping you cool this summer.HeadquartersYou lose a lot of body heat through the head, which might seem like good news

Wondering what makes a great product review? Look no further than the examples below.Written by some of our past prize-winning critics, they're sure to fill you with all the inspiration you need to get writing your own.Garmin Forerunner 205

, red, mango orange or black instead. Good for: those who like to travel light Osprey Talon 22 Backpack, £59 www.ospreypacks.com This spacious and stylish panel-loading backpack will carry all you need for a day of fast-paced fun or a

run and the parking brake when you stop – all good strollers have them.Consider taking a puncture-repair kit and a small pump on long runs.Two useful extras you can fit yourself: a bell to let people know that you’re approaching, and a bike water