London: Forget barefoot shoes and complex carbohydrates, the biggest improvement to your running times could come from this smart jacket.

The Glowfaster sports jacket syncs with a runner’s smartphone and then uses lights to indicate whether they are running at the right pace.

It can also make its lights flash in time to music to motivate runners to keep their pace and warns other pedestrians and vehicles of the runner’s whereabouts.

Ex-marine Simon Weatherall came up with the idea of the jacket, which has been designed by Joanna Kent, who has created clothes for Abercrombie and Fitch.

The company said: ‘Using our smart-jacket can help you train more instinctively. It allows you to sync your body’s biomarkers such as your heart rate, or measure speed versus target via GPS, letting you know when you are at your target.’

Mr Weatherall, who fought in the Iraq war, said he will donate 10 per cent of profits from the jacket , which will retail at £ 99, to the Royal Marines Charitable Trust Fund.