Interesting idea, but I have doubts…
a few more
you can do better than spend money on a torture device. Go out and X country ski. There’s snow all around you right now.
You thought I might actually buy one? No chance! Even if I had somewhere in the house to put it, I’d much rather do something outside than stare at a wall. Taking the dog skijoring is infinitely more entertaining – for all concerned – than yanking on bungees.
I just enjoy the ingenuity of my fellow man, even if – or especially if – the practical value seems dubious.