You have to really push your body pretty hard to be visibly shaking. I can often feel my muscles shaking when I’m lifting heavy, but it’s not always visible to bystanders. Today, we were challenged to hold a push-up position on a bosu ball. This is A LOT harder than it sounds. You’ll notice that I’ve got my knees down. I did this, so I could maintain a solid push-up position without arching my back to do so. Maybe after I’ve done this move a couple of times I’ll be able to be in a full plank position. Almost immediately, my arms began shaking uncontrollably. This did not help with maintaining my balance on the bosu ball, which of course just made the exercise that much harder. We did this 3 times for 60 seconds each time, so we were pretty wiped out by the last rounds. This move is really great, because it is not only a fantastic workout for your arms but also your abs. The addition of the bosu ball means that you really have to engage your core so that you’re not rocking back and forth constantly.