Find a hill... a kind of steep one... Start from the bottom and make a mark at the top... Run (sprint) as fast as you can to that mark at the top... stop... jog down the hill catching your breath... Do it again and again and again... Until you are warn out... It will help for the next time you run long distance... My cross-country coach made us do this... I hated it at first but now I do it on my own.. lol

You have to mix up your speeds by doing interval training. Start with a slow 15 to 20 minute warmup and then run strong for 3 minutes. You want this pace to be quite a bit faster than you normal pace. Then recover at normal pace for a minute and do another 3 minutes at a the strong pace again. Start with a set of 4 or 5 intervals. Do a interval workout once or twice a week. Try doing more the next workout or increase the amount of time on the strong portion of your workout. You will get faster. If you run the same pace all the time you won't. You can also incorporate track workouts. Start by doing a lap around the track at a fast pace and recover with a slow lap. Start with a set of 4 to 8. Ideally you want each fast lap to get slightly faster with each one you do so don't burn yourself out on the first one. Mix and match the distances. Always warmup first and don't try to push through sharp pains. If you do one interval workout a week and one track workout a week you'll amaze yourself with your speed improvement. Those fast guys that win your local 5k races don't do it on natural talent alone, they do interval and track workouts. Happy running.