His bizarre video workout with Kid Rock apparently wasn't enough, so Robert F. Kennedy packed up his game and headed out west to exercise with the Terminator. The 72-year-old secretary of Health and Human Services posted a selfie on social media that shows him posing with former California governor and action-movie star Arnold Schwarzenegger, 78, in a large room full of workout gear. "Senior's Day, Gold's Gym in Venice," Kennedy wrote Thursday, albeit with a misplaced apostrophe. The two men have been friends for years and were once related through Schwarzenegger's marriage to Kennedy's cousin, Maria Shriver. It ended in divorce . Last year, a paparazzi video captured the men leaving the same gym with bodybuilder Ralf Moeller. Robert F. Kennedy appears in a selfie with Arnold Schwarzenegger (Robert F.…