Normally, a wolf's running speed wouldn't be able to compare to a human's. A wolf with four legs would be able to run at top speed, and even if a human tried to catch up, they would only be miserably left behind.
That kind of situation would happen if it was a normal human trying to chase the wolf. But, was Bai Lang a normal human? No, Bai Lang was not a normal human, and he wasn't even human in the first place. Bai Lang was a part werewolf, and he was also the strongest among werewolves because he was the Immortal Elder.
Bai Lang had also died many years ago, and that was why he couldn't be considered a human.
Thus, it wasn't difficult for him to catch up to Shao Yaoting who was in his black wolf form, but he deliberately kept running behind the wolf instead of stopping the wolf's movements. He wanted to know where the black wolf would continue running.