By Tzvi Machlin Cleveland Browns running back Nick Chubb has been one of the NFL’s toughest runners for the entirety of his career. But that toughness starts in the weight room, where he recently showed that he’s an absolute warrior. A video has been going viral today showing Chubb training in the Browns weight room. In the 10-second clip, he takes a 675-pound barbell off the rack and does a squat as his teammates cheer him on. Chubb then effortlessly puts the massive weight back down as his teammates applaud him. The video already has hundreds of thousands of views on Twitter alone. It may ha…