Absolutely it is possible.
1. Find a hill 400 meters in length, do repeats until you drop. Press the anaerobic threshhold. Hills, hills, hills.
2. Throw garbage milesout the window, make every step matter and count; cut the mileage down and increase the intensity.
3. 1200-1400 meter repeats; start doing them, start doing 600-800 meter repeats with 3 minutes rest. Push push push and force your body to compensate for exhaustion, oxygen debt, be strong.
4. eat, sleep, get your diet adjusted appropriately.
Advice, 500 miles, 1000 miles, 10000 miles over the summer does not mean crap. Quality over quantity. Shorten your mileage and start training like a 15 minute 5k runner.