8.5 mile progressive run - sort of

I decided that I had time this morning before I flew back to Houston to get a run in and I would rather do it in the cooler weather in the morning than in the 90 degree weather in Houston.  I planned on doing an 8 mile progressive run starting at 7:00 pace and dropping 15 seconds a mile and ending at 5:15 pace.  My allergies had really been acting up yesterday so I took a claritin pill this morning right before I went out on the run.  I haven't used Claritin much and I haven't been able to figure out yet how much of an effect if any it has on me.  It was warmer and more humid than I was expecting.  It was in the mid to upper 70's, humid and sunny out.  I started out and my left achilles was pretty tight and I could feel the plantar fasciitis in my foot.  I hit the first mile in 7:06 and by the middle of the 2nd mile I was pretty well loosened up and it wasn't bothering me anymore.  Mile 2 was 6:43 and Mile 3 was 6:31.  Mile 4 was mostly downhill and I hit it in 6:06 without much effort.  After another 1/4 mile I turned around and headed back.  Mile 5 was mostly uphill and I just destroyed myself trying to go sub-6:00 back up the hill which was pretty steep.  I'll have to download some of the data off of my garmin and see how much elevation change there was, but my hard run was basically over at that point.  I think I was getting a little dehydrated and the sun was beating down so I stopped and walked to recover at the top of the hill.  There were a couple more hills on the way back so I ran easy to the hills and then ran hard up the hills and then ran the last couple of miles at about 6:45 pace for a cooldown.  i did the 8.5 miles in about 55 minutes.  I'll do an easy 7 miles tomorrow and then a hard workout on Wednesday and then work on just getting some good mileage in the rest of the week.