I was solo this morning at the Auguston Stairs, so without anyone else's pace or time constraints to think about, I decided to push my limits a bit. I set out with a pace intended to see me through 15 sets of stairs, with the aim of seeing what would quit first - my legs, my lungs, or my head.
The answer? None of the above.
My pace was not slow, but not super fast. I completed 9 sets in 1 hour, and finished the 15 in 1 hour, 40 minutes. 15 sets is not really that much worse than 10 - it just takes longer. My legs are a little more tired maybe, but really it all felt the same from about 7 or 8 onwards.
A few groups of other people came and went in the time I was there, and I kept pretty near the same pace the whole way through, only really slowing noticeably in the last few sets. Even then, though, I felt like I could have kept going and done 20 or more sets if I wanted/had to.
So...15 sets = 3,000 feet of elevation gain, and 5,370 stairs each way (up and down). I'm planning on another 15 sets (total) this week, before heading off to Calgary/Red Deer for the Spartan Super and Spartan Sprint on Labour Day weekend.
I haven't found my limit yet. Now, to go soak in the hot tub... :)