"Trainers Hate Him" is a quote from an online bodybuilding supplement advertisement claiming that personal trainers are frustrated by a man who uses their product. The phrase is often quoted in fitness-related discussion forums in response to implausible claims related to fitness and bodybuilding.
The phrase was first used in a series of advertisements for the Force Factor bodybuilding supplement (shown below) that began appearing online as early as August 2011. The ads typically featured a man with prominent upper body muscles accompanied by a paragraph claiming that "Cambridge scientists" had discovered a powerful new muscle-building supplement.
On December 4th, 2011, Yahoo Answers member Reef submitted a question asking if people had seen the Force Factor ads. On January 10th, 2012, BodyBuilding Forums member PuNjAbixxPheNoM posted one of the Force Factor ads in a thread titled "Trainers hate hm." On February 19th, 2013, a "selfie": photograph of former professional bodybuilder Andreas Cashling to the /r/pics subreddit, to which Redditor Juggernaut1 commented "Gym Trainers hate him!" On May 16th, Flickr user kadigan uploaded a mock Force Factor ad featuring a painting of the fictional character Popeye by Deviant Artist axlsalles. On August 1st, Sonic the Hedgehog fan blog Not Another Sonic Blog posted a two-pane image of the character Tails transforming into a muscled version (shown below, right).
Similar advertisements for other products have circulated online as well, including a "dermatologists hate her" skin product ad (shown below, left) and a language professors hate him" language-learning product banner (shown below, right). Often, these advertisements are created by hackers to lure people into clicking on them and allowing viruses to enter the computer.