My summer of training has gone completely downhill since the end of June. Right away my legs were heavy and dead and my pace was awful. I backed off training for a couple weeks and did just short easy runs. That didn't help, I went to a doctor and got blood work which came back normal. Its been 2 monthes and I am nowhere near where I was in June, my training is terrible now. My coach has me doing easy 3 and 4 milers and even that is tiring and way slower than it should be. No one can give me an explaniation about what is wrong. Does anyone have any ideas?