I am a cross country runner going into my senior year of high school. I really want to run some good times to finish off high school and be competitive in my league, but no matter what, I can’t seem to improve, and this summer is my last chance. Freshman year XC I ran 20:10 in the 5K, over the winter I grinded out three hard workouts a week running about 20-25 miles a week leading to a 5:01 in the 1600 and around 11:00 in the 3200. Summer before sophomore year I bumped up mileage to about 40-45 but kept it all mostly easy and ran 18:08 in the 5K. I tried bumping up mileage to 50 over the winter but got injured and dropped back to 40, which led to a 5:00.13 in the 1600 (my current PR) and a 10:54 in the 3200. Summer before junior year the same thing happened-I tried to increase to 50, got injured, and dropped to 40, and ran 18:06 in the 5K. I took track off this past year and trained on my own about 40 miles a week since I was scared to try to increase mileage and ended up running a 17:37 5K in a completely flat road race that might have been a short course (so probably around the same as my previous times). Solo time-trialed a 5:07 1600 about a month ago to end my “track season”. Does anyone have any advice on how to stay injury free and increase my mileage, since I can’t seem to improve? I really want to run sub-17 in the 5K, but I can’t figure out how other than increasing mileage, which never seems to work for me when I push too much past 40. I’ve been holding 45 the past few weeks here and want to bump up into the 50s this summer if possible.