The unique challenge is to run as far as you can in one hour so a sound race plan is essential. Set off as if you are running a 5k and you'll have shot your bolt before half-way. Dawdle at marathon pace and you'll finish fresh but disappointed because your running buddy has gone a kilometre further.

A lot of the fun around the adidas City Run 1 Hour is in the unusual format which will intrigue those of us who've settled for the standard 10K before.

It's a great location too - central London, and the closed-road route features St Paul's Cathedral, Guildhall and Mansion House. The entry package includes an adidas tech T-shirt, free finisher's photos, free yoga and a free massage.

It's you versus the clock on Sunday 17 June. As part of your entry you will receive an adidas tech t-shirt, free finishers photos, free yoga and a free massage.

Full details at the adidas City Runs website.