The miles you run should be in a good steady pace. It shouldn't be so fast or to slow. To start you need to find out how many miles you can run without stoping. Then you set a pace that will let you run for about an hour. For example my pace is about 7-8.5 mph, and I run about 7-9 miles a workout. I would recommend about 4-5 days of long distance 1-2 days of speed workouts. Now #2-6 is a good speed workout that I call "The Bear"
Eight 100 meter sprints
One 800 meters at 80+ second laps
One 400 meters at 75+ seconds
Three 600 meters at 95+ seconds
Six 300 meters at 65+ seconds
Tell me if you guys like my workout plan. By the way my name is Oscar Rodriguez I am 15 years old and I want to become one of the best and one of the youngest marathoners out there.