Mayweather Boxing Club, Las Vegas - Luis Sandoval catches up with WBC/WBA welterweight and junior middleweight champion Floyd Mayweather Jr., who is preparing for the upcoming rematch with Marcos Maidana on September 13th at the MGM Grand. Mayweather shows off his hand speed, stamina and work ethic in throwing 1,300 punches on the heavy bag and then unloading combinations on the mitts with his uncle/co-trainer Roger Mayweather.