The current fastest known time for running/hiking around Mt. Adams is 8 hours 41 minutes, starting and ending at Cold Springs on the south side of the mountain. This was completed by Lucas King, Alex King, and Tim Dearden on August 9, 2011. Other documented attempts have been performed that have ranged from 10-18 hours and have utilized many different routes.
8 Hours 41 Minutes
Link to Garmin Connect Activity:
Around Mt. Adams Record Time