West Monroe Police charged 19-year-old Landon Wayne Duke after two men flagged down an officer and informed him of Duke's comments.
Duke had approached the men, who he reportedly knew, and noticed they had guns in their truck, according to a police arrest report obtained by The Monroe News-Star.
The men claimed Duke said he wanted to borrow their guns to rob someone of enough money to leave town. The men said no and entered the gym, according to the arrest report.
Duke allegedly followed and worked out with the men while continuing to talk about robbing someone, investigators wrote. Police later spotted Duke at nearby a gas station and found what they believed to be methamphetamine wrapped in a $100 bill in his pocket, the newspaper said.
Duke was booked into Ouachita Correctional Center on Sunday on one count of possession of a schedule II controlled dangerous substance. He remained in custody Monday with bail set at $3,000, the News-Star said.
The Associated Press contributed to this report.