...had doubled in height!
When Arthur awoke the next morning, he discovered that he had doubled in height.
He went back to the gym and checked his height and it said 18ft!
"Holy shit!" Arthur said, gobsmacked. "I've doubled in height! I'm 18 feet tall!"
Once he had his breakfast and shower, he went to get dressed, but immediately he found a Problem - None of his clothes fit any more. His shoulders were too wide for the shirts, and his butt too big for the underwear and jeans, causing many a torn seam.
"What am I to do?" Arthur sighed. "I can't go out anywhere. Nothing fits."
Arthur knew what he could do - make his own clothes.
He gathered up his spare bedsheets, some big safety pins, and fashioned a makeshift toga out of his bedsheets, using the pins to fasten his sheets together.
He now has his very own Roman toga.