Harper has worked as a personal trainer for celebrity clients, including Jennifer Jason Leigh.[1] In 1999, he was cast as an extra in Melissa Etheridge's hit video for the song "Angels Would Fall" from her album Breakdown.[3] He is featured as a trainer on the United States version of The Biggest Loserreality television series. He has been a trainer on the NBC show since 2004.[4] and has appeared in several Biggest Loser DVD workouts. On September 8, 2015, Harper was announced as new host of The Biggest Loser, succeeding Alison Sweeney.[5] Harper is also featured in the first three seasons of the Australian version of the show.[6]
In addition to making appearances, speaking dates, and writing, Harper teaches regular classes in Los Angeles and works as a yoga instructor.[7]
In early 2010, Harper launched mytrainerbob.com, a website where subscribers could discuss weight loss and receive coaching.[8][9] The success of his site led to the release of his first workout DVD series in May, titled "Bob Harper: Inside Out Method."[10] Harper has also contributed workouts to the Shape magazine website.[11]
Harper has spoken out against puppy mills and has adopted a black and white dog from the Animal Advocates Alliance in Baldwin Park, California. He named the dog Karl, after Karl Lagerfeld, because of the dog's color.[19]
Harper is Farm Sanctuary's 2010 Walk for Farm Animals national spokesman.[20]
Harper publicly came out as gay in the seventh episode of the fifteenth season of The Biggest Loser,[21][22][23] while talking to a contestant who was having difficulty telling his parents about his sexuality.[24] Harper revealed he had come out to his parents at 17, but that this was his first time ever addressing his sexuality publicly in his career. The episode aired on November 28, 2013.
On February 12, 2017, Harper suffered a heart attack; his survival being a subject for his commercial for the Brilinta medication.[25][26]