For context 8 months ago I was a sophomore running 15-25 mpw and no summer training. my prs were 20:43 in XC, 5:21 for the mile and 2:15 for the 800. Fast forward to my Junior year and now I'm running 17:11 Xc, 2:49 1000m and 4:52 for the 1600 indoors. I'm currently averaging 45-60 miles mpw this winter. I know I could run much faster in these events it's just my school doesn't go to many meets so I've only ran the 1600m twice and 1000m once. What should I do to run to run close to 4:30 this upcoming spring?