Su Changkong probably understood the reason.
Based on the genetic constraints of the innate races, few people live past a hundred years, and their life span's limit is around one hundred and forty to fifty years. This is the shackle of the race, very difficult to break through.
It is just like how the body grows to a certain limit, and no matter how much one trains, it's hard to increase strength or speed any further.
Su Changkong didn't dwell on it too much; he was still very young and had plenty of time to cultivate in the future!
"I have hit a bottleneck, my Inner Strength has almost reached the limit my body can withstand. The fundamental reason is still my realm, which is just at the Qi Blood One Transformation. If only... I could eat without restraint."
This breakthrough had almost pushed Su Changkong's Inner Strength to the limit his body could bear, which was a rare situation.