(I apologize in advance to those of you who might not want to watch a heavily muscled man in admittedly small shorts. If this is you, just ignore this post. But if you're up for it, this is really sort of amazing.)
You may already have seen this, but I had not until just a few minutes ago. It's fun to watch, but then wait a bit when the video ends. It's not over.
Here's a tip: when you see the record button, click it, then hit some keys on your keyboard.