I ran a 16:36 5k this past xc season and I was only running 30-35 mpw. I ran 44 miles this week with a 10 miler yesterday. Is this a good idea to bump up the mileage?? And how did I manage to get 16:36 with that training? I don't understand because I see some runners doing 70-100 mpw and they can't break 17.