Ran for 2 miles in a stiff head-wind

I forgot to check my wakeup heart rate, but I felt pretty good. The air temperature was about 40 (F). There was a 15-20 mph south wind blowing, and I ran for a mile with that head-wind. At that point I turned around and headed back to my car, because I was getting tired from that head-wind and probably from not being fully rested since my run on Saturday. Having a tail-wind on the way back helped, but I was still tired and ran for shorter phases than I had on my way out. My running phase is normally 2 minutes and my walking phase is normally 1 minute.