I fully believe I am capable of running quite a bit faster over distance than I do at the moment seeing as I can run 400m at 5 minute mile pace and 800m a little under 6 minute mile pace, however my mile is in the 6:20-6:30 range, to be honest I am a bit displeased by that as I have been hoping to break 6 for some years now but I always plateau when I reach the mid to low 6s. It would be quite sad to think I have maxed out my running speed ability. I just do not really know what sort of workouts I should be doing and how quickly it is appropriate to build up miles each week without risk of hurting myself. Over the last 8 months I have done a lot of track repeats around 5:00-7:00 minute mile pace and although the slower speeds (8:00-10:00 minute mile pace) seem to be feeling easier, the faster paces still feel just as hard. It would be easier if I could afford coaching but that isnt an option so for the most part I will have to either test things myself or ask other runners on the internet.