The first week was brutal.
Sasuke's body ached constantly. Every muscle screamed. His chakra reserves felt depleted permanently. He passed out at his desk twice from sheer exhaustion.
But he adapted.
By day three, the ten laps didn't feel impossible. By day five, he was finishing in under thirty minutes. By day seven, he was down to twenty-eight.
The calisthenics got easier. His body remembered muscle memory from before—original Sasuke had been well-trained. The new knowledge just helped optimize everything.
Chakra control was more interesting.
"Tree walking," Kabuto demonstrated. He walked up a tree trunk like it was flat ground. "Basic technique. You should know this already."
Sasuke did. Made it up the tree on the first try.
"Good. Now do it while juggling kunai."
That was harder. Took him four tries to manage it without falling.
"Now do it while performing hand seals."
Even harder. Split focus. Maintain chakra control. Execute seal sequences. Sasuke fell six times before getting it right.
"You're adapting quickly," Kabuto noted. "Most students need weeks to manage this level of multitasking."
"I'm motivated."
"Clearly." Kabuto pulled out a scroll. "Tomorrow we start ninjutsu training. Lord Orochimaru wants to see what your Sharingan can copy."
Finally. Actual technique training.
That night, Sasuke lay in bed reviewing the day. His body hurt, but it was productive pain. He was getting stronger. Building the foundation he'd need.
One week down. Many more to go.