All the same, it is difficult to prioritize here, since both exercises still have a different form of load and include different emphasis on muscle groups in the work.
Again, what is meant by slow running and brisk walking!
Brisk walking (as it should be) - requires high power costs and develops the qualities of special speed and speed endurance. While slow running is more of a work on general endurance with an emphasis on the development of the general functional work of all muscle groups.
But again, this is how to understand the words fast walking and slow running! You can walk a little faster than the speed of a standard step and make a slow run, almost like a step to walk ... (just were in memory, people who walked and ran like that passing it off as training)
When running, more muscle groups are involved and they perform more diverse actions than when walking, so it can be assumed that the metabolic processes in a runner are more intense than in a walker, which means that calories will be spent faster.
And running causes more physiological stress than walking, with increased activation of neurohormonal systems, which also spur metabolism.