All perfect praise be to Allaah, the Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
It is recommended in both Hajj and ‘Umrah to do Ramal (fast walking) in the first three rounds of Tawaaf and to hasten between the two green marks in Sa‘y (between Mounts Safa and Marwah). Anyone who cannot achieve that due to overcrowding or because he forgot or for other reasons is not liable for anything. However, an act of Sunnah should not be deliberately overlooked without an excuse. Also, interrupting Sa‘y to drink water does not affect the validity of Sa‘y because it is a negligible matter. Al-Baaji, a Maaliki scholar said, “A pilgrim who buys, sells, or performs a funeral prayer in the course of Sa‘y can resume Sa‘y if the activity is short. If it is long, then he has to start over from the beginning.”
Allaah Knows best.