What is better for increasing cardio staying power?

What is better for increasing cardio endurance: Running roughly a mile respectively day or power walking roughly for an hour respectively day?What is better for increasing cardio staying power?
I'd stir for the hour. Running a mile is only 6 or 7 minutes worth of exercise.
Both can bring about the same but walking is not frozen on the joints as running is. You're incompatible your knee joint every time your foot hits the pavement.
power walking for the hour by far. You are exercising longer that way. Running a mile isn't going to run you anywhere near an hour.
it would depend on the terrain you are running and walking on, walking uphill would be far better than running on flat surface. your cardio will increase any way as long as your pushing yourself.