So no matter what the workout or run, I always feel like crap. It doesn't matter if I'm starting off at 5:20s for a tempo or taking a very easy recovery day at 7:30-8:00 min pace, all of my runs start out feeling terrible. It can take as much as 15 minutes for me to feel good, but upon starting out I am almost always winded and breathing hard. I've noticed that the better shape I'm in, the harder my runs feel right off the bat. When I was out of shape and just getting back into training, I'd feel GREAT at the start of all my runs and then get super winded and exhausted rather quickly. However, now that I'm in shape I start off feeling tired and very winded only to end up feeling strong and even effortless from the middle to the end. I don't feel burned out or anything and my iron levels and blood work is all good, but for some reason my body seems to take forever to 'warm up' now... Is this weird or what??