Half a hard run

Today I couldn't keep the pace. I'd say 30 minutes of the 60 were at a good effort but then one hill just bit me so hard I had to back off the pace. Ended up with 8.07 miles @ 7:27 pace. HR 156.

The heart rate tells me that perhaps I was running the first half too hard. A look at the splits:

8:26 warmup
6:44
6:46
6:47
7:21
7:32
8:04
7:50

Looks like I had to back off considerably there after mile 4 and then again after mile 6.

Wx: mist 43F