There should be a number of hops specified in the old-age test. I mean, it's a lot easier to lift one foot off the ground and then make ONE quick little hop than it is to bounce up and down on one foot for multiple repetitions.

I can hop once or twice, maybe a half-dozen or so times, but wouldn't want to go much longer. I think I'd be able to quit, nd would quit, before I'd lose my balance completely and fall on my face.