Name: HRC of Running
Author: x12dev

This CIQ data field computes, stores and displays Heart Rate Cost of Running which remains pretty constant between various kinds of workouts and only varies as you improve your running performance. In contrast to other CIQ fields which simply compute heart-beats per distance unit (beats per mile or beats per kilometer, depending on system settings), this field also takes into account your resting/orthostatic heart rate as a direct measure of Basal Metabolic Rate which corresponds to zero-power and thus zero-speed of your activity.

So how does this field work exactly? For example, your 7-day average resting heart rate is 45 beats per minute. When you stand up, approximately 500 ml of blood descends from the thorax into the abdominal cavity and limbs. A normal autonomic nervous system responds with immediate peripheral vasoconstriction and increase in heart rate of 10–20 bpm (15 in average).

Then, 45 + 15 = 60 bpm and this is your orthostatic heart rate. At this heart rate you just stay still and don't move thus producing zero of running power. Now we can compute Heart Rate Cost of your running activity. For example, you run at 180bpm and 04:00/km pace. Then your HRC = (180b/min - 60b/min) * 4min/km = 480 bpKm (beats per kilometer) - this is a direct measure of your running performance which is nearly constant while you running below the lactate threshold. For example, running at 156 bpm and 05:00/km pace results in the same 480bpKm heart rate cost.