I am a freshman in high school and just finished my first year of xc. I like it a lot and was the best freshman on my team and in my region this year. My PR from this season was 17:35 and 5th on my team, I also broke 18 2 other times and ran mostly in the 18:20-40 range all season until my championship races. My older brother (whos a college runner) thinks I could run around 16:30 next year if I train but I think I might be able to do better. I also want to run under 4:50 in the mile for track or under 10:30 for the 2 mile. Is this possible or should I set my sights lower?