Today I went for an easy run. 10km total. 5 miles steady running, and 1.2 miles run/walk cooldown. The weather wasn't as nice as it was last week. It was cloudy, it rained a bit, and the temperature was around 8°C, with winds about 10 km/hr. On the way out the wind was in my face, but it was at my back on the way home.
I kept my heart rate under 70% of heart rate reserve, for the most part. The large dip in the heart rate chart after mile 1 happened as I was running down the big hill to the Isar River valley. The big spike just after mile 5 occurred as I was running up that hill on my way back. The peaks and dips during the last mile correspond to my walk/run intervals.