I'm 15 and run cross country and I'm one of the slowest people there. I really want to get much more endurance and speed but feel like I'm not making progress. I workout most the time ( six inches, planks, push-ups, jump rope, weights etc) but I don't know what to do. I'm a freshman and my fastest mile a month or two ago was 6:50. About 5'4-5'5 weight 120 Im not sure if you need that information I'll give more if needed