Does anyone else have this problem? So far I can only do single jumps. In each practice session, after I jump for, say, 15-20 times, my jumps will start to get worse. I will bail out more often, have shaky landings, or underrotate. I don't really feel tired. I can still keep skating and practice other things. But it feels like it's getting harder to keep everything right when I jump. It makes me think "Half an hour ago I can still do this jump, but now I can't do it anymore." Is this a stamina problem, even if they are just single jumps? What should I do?