"Hey Jake," came Elliot's voice as he sat down beside him.
"Hey Ellio- what the hell?" Jake cried as he looked at his brother.
The younger boy was shirtless, and boasting an incredibly muscled torso. It was like a bodybuilder's torso shrunk to child size, with perfectly defined abs, large, solid pecs, and biceps that bulged a little, even when unflexed, showing the definition of his arms. His legs were muscled looking too, filling his shorts much more than before. He looked like a superhero, being hugely muscular, but still somewhat lean. "What'cha think?" Elliot asked, flexing one of his large biceps
He was a couple inches taller too, normally about 4'3'', he was now about 4'8''. He was shorter than Jake still, but definitely stronger. "Dude, that's awesome," said Jake, feeling his younger brother's solid muscles.
"Wanna wrestle?" Elliot asked, pouncing on his brother before he could respond.
Jake groaned in pain as the heavy, muscular eight-year old landed on him. He was too heavy to move too, and was pinning him down with his impressive strength. "Dude, get off," groaned Jake.
"Oh, sorry," said Elliot, getting to his feet, "Guess I don't know my own strength yet."
"Clearly," grunted Jake as he caught his breath, "But why the muscle?"
"Well I wanted to be bigger and I read this thing on the computer about a muscle contest on the beach and thought I'd join. I have to pose and wrestle."
"Can you pose?"
"Sure," said Elliot, pulling off his shorts to show a posing speedo.
The young boy promptly went through a series of poses, showing off his musculature, including his wide, v-shaped back. Even his bulge was bigger, but Jake didn't want to think about that part. When he was done he stood there in all his muscular glory, waiting for feedback. "Pretty good, but I'm guessing you want my help to prepare?"
"Yup!"
"Can you get any bigger than that?" Jake asked.
Elliot rolled his eyes, "Oh come on! Weren't you listening! He said you can change in any way in this room."
Before his eyes Elliot began to grow, proportionally, so his muscle didn't diminish one bit as his height increased. He inched upwards, and Jake got to his feet to see Elliot now stood about 5'5'', the same as him. He still looked like a muscular eight year old, just a very oversized one, and he grinned as he inched upwards in height to 6 feet, then stopping at 6'5'', making him a whole foot taller than his brother. He now looked positively massive. "So little brother, will you help me?" asked Elliot eagerly.
"Sure," replied Jake, "But what do we work on first?"