Over the summer I only ran about 30-35 miles a week pretty slow. Once the season started, I felt good for the first few weeks and the first meet, but this past week my legs have just felt dead right away every run. Even our second cross country race (i ran low 17's but lost to 5 guys on our team who I always have beaten). I couldn't even finish our last workout because at the start of it my legs just felt heavy and gone already. does anybody have advice? thanks in advance