Am I coming up short?

They say that, if you use a step-up box for off-bike exercises, it should be approximately twice as high as your crank length. The box I have, meant for aerobics,  is about the same height as my crank length. According this advice, that\’s too short. But I use it because it\’s what I have. That\’s how I was brought up: Use it up; Wear it out; Make it do. And when it\’s worn out, do without.

Besides that, I\’m reluctant to bring more stuff home. I\’ve got more than enough stuff already; and I don\’t need to crowd myself or my bicycles out of here.

If I did buy a taller box, the old one would have to go. And who would want it? It\’s ancient, after all. I\’m not even sure it\’s in very good condition any more. So, even if it\’s technically too short, I\’ll keep on using it. Better I should be coming up short than to have no box at all!

Speaking of stepping up, I\’d like to know this: why is climbing a flight or two of stairs more tiring than riding a bicycle for several hours?