I assume you are talking about 2.5 mile times? Or has CC gone metric to 5K? I would highly recommend you vary your training distances from day to day and include at least one day a week of wind sprints and 2-3 weight workouts per week. For example a good routine might be:
Day 1: 3 miles
Day 2: weight workout
Day 3: wind sprints, for distance runners this should be 100-200 yards of sprint followed by 100-200 yards of slow jog, repeated for 30-40 minutes or 3-4 miles
Day 4: 3 miles
Day 5: weight workout
Day 6: 6-8 miles
Day 7: rest