I wore a HR monitor for the first time during a tempo today. I ran the 4 mile tempo at about the same effort as ussual - started easier and finished fairly hard. My average HR was 169 (I'm 33). I started in the low 160's and ran the last mile at close to 180 the whole time. Is this to hard based on my HR? If I averaged 5:22 pace, what would people suggest is a good goal tempo pace. I have no idea what I could currently run for a half. Thx