I'm a junior who runs a 18:30 5k, 5:20 mile, 40:18 10k, after xc ended I began training for track. I'm doing about 30-35 mpw and have taken 4 off days. My goal Is to break 5 in the mile this year, and run low 17s next year. What workouts are good for improving, and how else can I better manage my training?