I have staggered up a 30% slope at 6000m, and remember taking a few steps and then having to have a breather (albeit with equipment and food weighing me down).

I have staggered up a 30% slope at 6000m, and remember taking a few steps and then having to have a breather (albeit with equipment and food weighing me down). Although I do ice climb at lower altitudes, I couldn't imagine effort to do the same at 6000m. What was it like? Make 2-3 moves, then stand for 30 seconds to catch your breath?!?