I completed C25K about 5 weeks ago (shuffling along at 4.5mph) and since that time have focused on increasing the duration of my runs while staying at the same speed. Does anyone know of a good program to increase speed? My goal is to run comfortably at 6.0 mph or better. Today I started to increase the speed slightly to 5.0mph and moved from 50 mins back to 30, but I'm wondering if there are any better approaches. I never thought I'd be asking this on week 5, but running/jogging/shuffling has been a great way to challenge myself and I'm hooked.