Han Sen was convinced that he had strong potentials. After all, he had already gained super geno points.
However, in order to tap into his potentials, he had to work extremely hard. He could understand his weaknesses and strengths better under extreme conditions with Overload. This way, he could develop his full potentials.
A high level of understanding of his own body was necessary. He had to know exactly where he could work harder. Otherwise, he might push himself too hard so that his body would collapse.
The process of practicing Overload was a process to learn how to control his body. He had to make sure that each bone, muscle, and body cell were working at the limits, but not over the limits, which was the ultimate goal.
Certainly, Han Sen had not reach that level just yet. Because of Jadeskin, he had much better understanding and control of his body then an average person, which was conducive to his Overload practice.