It is interesting to compare my racing style and physical outcome between full marathons and half marathons.
I don't train for speed at all. In fact, while I do exercise a couple of hours every day (not all running), I have no "training plan." I just do what I want. And since I run many marathons, I don't ever try to go fast. Going fast puts wear and tear on my body that I don't really need.
Last Saturday dawned clear and cold (for the Gulf coast). I felt good. When the gun went off, I took off. I found that I was easily running 9:30 minute miles. I just kept doing it. I finished a half marathon in 2:05. Dang good for me. I haven't done that in 4 years.
But I was more exhausted after that than I am after a slow 26 miles. My next race is a challenge. Marathon on day one and half marathon on day two. It probably will be hot. So last weekend is it for speed for me this year.