I live in a former coal mining area and near my house is a large slag heap, with steep sides that mountain bikers love to cycle down.

I have done some running up the slopes in the past, and it really takes it out of you, getting the quads and calves aching as well as working stamina.

From a MA perspective would you consider it better to do this once as part of a longer run (which is how I've always done it)or to do several "sprints" up then walk down, I reckon I could only do it about 3 times before failure.