I have used a 13 week program called "Goal Mile" with some of my athletes with a lot of success for a couple years now. It is a 13 week program which involves a track workout each week a long with a second run (in most weeks) to help you achieve faster run speeds then you ever thought possible. It is a fresh new approach to track workouts and it has also been my experience it helps to elevate ALL your running speeds. Even if you are a long course athlete this plan will still help you. Most of my athletes use this plan regardless. What happens when you start going long all the time is speed starts to diminish. This will help boost your speed and economy.
Here is a link to the plan. It is 30 bucks. It is supplemental. So you can use it within all the other things you do. It is only 1 -2 workouts a week for 13 weeks. So if you are coached, you might be able to use this as well, or self coached, you can still do your normal schedule, just add this in.