Background info: I used to be a LOT faster when I first started running. Each training cycle keeps getting worse and worse, and I completely blew up running my last half marathon.
I've been looking through my old training logs, and I've noticed that my heart rate at a 7:47 pace during a 13 miler in the middle of summer two years ago is the same pace I ran yesterday when running a 5 miler at a 9:00 pace in much cooler weather. I've also noticed that I now sweat a TON when I start running. I'm usually extremely cold otherwise. Like wearing a sweater when everyone else is wearing a t-shirt. Any ideas what could be wrong and how I can reset my body?