The running vs walking debate is age-old but a recent study says brisk walking is healthier than running. Does that matter to runners? Shikha Kumar finds out. This is not exactly breaking news but it will give walkers something to crow about as they go about their daily exercise. And instead of looking enviously at the 'cooler' joggers who sail past them kitted with headphones and MP3 players et al the walkers will be smug in the knowledge that brisk walking is doing their hearts more good than running. A study published in April in the American Heart Association's (AHA)