Abdullah bin Umar used to walk rapidly in three rounds of his Tawaf when he came for Hajj or Umrah, and walk (at a normal pace) in four. He said: "The Messenger of Allah used to do that."  

وَكَانَ رَسُولُ اللَّهِ ﷺ يَفْعَلُ ذَلِكَ