Some years ago I was at the Patent Office in DC, before it got online, doing some searches on various exercise devices. Right on the top of one of the category piles (which means it was granted recently), was some paddle-weight device fer yer shprontz. It was actually resistance based, like a weighted/sprung see-saw or sumpn, and sposedly, thru progressive resistance yakety-yak, made it harder/stronger.
Which is absurd, but that don't matter when it comes to granting patents, not at all. Only in the case of claims for perpetual motion does the PTO get a little picky. Your patent/claim doesn't have to make sense. It just has to be original. And in Europe, it don't even have to be original--they just rubber-stamp'em, and let the patent owners duke it out in court.