Hi There,

I have noticed a couple of times recently that while running on a cold morning my heart rate is elevated for a slow running speed. Yesterday morning I ran and the temperature was 3.7 deg C. I was doing a graded exercise test. During my initial 10 min warm up running at a very slow 8km/h my heart rate was nearly 160, which is the heart rate i would usually see running at circa 12km per hour. I felt fine and ran my test and my heart rate actually went down as i sped up. See test results below. I'm male, 45, relatively fit, not over weight and had a ECG stress test a year ago which did not show any issues. Is this high heart beat on a cold morning normal?

Speed range held for 1 min each
Speed     HR average
8.2          158
8.6          162
9.2          160
9.7          153
10.4          138
10.9          139
11.4          142
11.6          146
12.2          156
12.5          168
13.3          160
13.5          161
14.3          167
14.4          167