"Sure enough..."
Lin Ke repeated the experiment several times. The Delicate Illness Extraction Technique could repair cellular-level damage according to the amount of chakra supplied.
The only problem was that it was too delicate, making the repairs rather slow. After being stabbed, the rabbit had tragically died before much could be healed.
This technique was pretty useless for emergency treatment in the field, not even as effective as directly using chakra to heal. It probably would not be much use against cancer or viruses either.
But for completely removing necrotic lesions and repairing bodily damage, it was absolutely bug-level. And he immediately thought of another use—
The role muscle damage played in physical training, which had been mentioned before.
For ordinary people on Earth to build muscle, they needed to increase mechanical tension and metabolic stress, causing a certain degree of muscle damage so their bodies would realize they needed to grow muscle. To put it bluntly, they put their bodies under pressure through weightlifting, weights, or extensive strength training, making their bodies "think" they had to build more muscle.
Muscle damage and repair were merely the final result. The key was the stress placed on the body beforehand.
People in the Naruto World did not need anything so complicated, especially ninja. Chakra extraction itself created considerable stress. The more the cells were squeezed, the more stress and pain it caused. Thus, people in the Naruto World only needed to slightly tear their muscles, then wait for them to recover and grow stronger.
Since chakra was the source of that strain, the body naturally adapted to being squeezed by chakra.
The common point was that the degree of damage had to be carefully controlled. Damage that was too light did not create enough stress, while damage that was too severe