It's really scary, but he does know how to use the elliptical. He grabs hold of the cross-brace on the upright and puts both feet -- all 35 pounds -- on one pedal, and the pedal oozes slowly forward or back. When it stops, he steps over to the over pedal and the same thing happens. Sometimes he even gets up some momentum, and the whole thing begins to look like something Jackie Chan would do on Land of the Giants.
Of course, I only know what it looks like close up, since my job is to have one arm around his torso at all times spotting him, and the other arm pushing or pulling on one of the handles to make the thing go in a predictable fashion. Imaging leaning over at the waist slinging a 30-pound sandbag very slowly back and forth with one hand while cranking an old-fashioned pump handle with the other. When I announce that I'm tired, C gleefully agrees to rest and pelts down the hall to the den. Sits down on the sofa for 10 seconds and then announces "On your mark, set, go!" for the run back to the elliptical.
All I can say is thank goodness for freecycle.