So that's two reps sessions in one week, Travs! Even when I was racing regularly, I never managed ore than one lot of reps in a week. These days, my reps sessions are about as rare as Tindersticks going for a fortnight without a race; but I did manage one on Wednesday, 8 circuits of a rough field near my home, about 2 mins per circuit, so no more than 500 metres.
If you get fed up with your stairclimber, you're not too far from the mighty mountain of Nuneaton
http://wikimapia.org/4198678/Mount-Judd#/photo/3010170 . Try some reps up and down that!