Originally Posted by
Mike T
Normally, if we use more power, we use the anaerobic pathway more, but in addition to the aerobic pathway, so it feels harder and if anything our heart rate goes up. Presumably you are referring to the fact that when we stop running and start walking because of the increasing gradient we are using our muscles differently, so that, to an extent, it is as if we are starting again. Once we have reached a new equilibrium, walking uphill can be as hard or harder than running on the flat - the easiest way to monitor this is to observe your breathing.