Ning Qi discovered one thing. When he was in the body training stage, upgrading could increase his blood volume, but he had just upgraded from a one-star fighter to a two-star fighter, but his blood volume did not increase, only his fighting spirit increased a lot.

"System, why didn't my blood volume increase after upgrading?"

"Only if the host has practiced the middle-grade yellow-rank or above kung fu, can he increase his blood volume when leveling up. The body training formula is only effective for the body training stage."