Gu Yue was secretly angry but he was shocked as well.
No wonder when King An sent them, he exhorted them to be wary of Chu Li's Light-body Technique. Initially, Gu Yue had thought that his own Light-body Technique was good enough to be extraordinary in the martial arts world but he did not think that Chu Li's skill was not lacking despite such a young age.
Gu Yue did not activate his secret technique to stimulate his potential. Otherwise, his speed would double up.
He was still rational. If Gu Yue really did that and unleashed all his capacity, he would need to rest for a day and if the Princess saw that, she would laugh her head off.
More importantly, if he used his secret technique, Chu Li might do the same. If this happened and he lagged, then Gu Yue would lose his reputation entirely. It was always good to leave a leeway.