a famous person in the personal training industry would be Jeff Seid, who has over 1 million followers on Instagram, is part of the Gymshark team, and runs an online person training business and has several books on how to build a better physique.
Arnold Schwarzenegger - Arnold is arguably the most famous bodybuilder of all time; now in his 60s he has now taken to spreading his extensive knowledge of the human body. Arnold has several books and videos such as Blueprint to Cut and Blueprint to Mass. He also sells his own line of supplements designed to optimize clients' weight loss, muscle gain, and overall fitness.
Christian Guzman - The owner of Alphalete, Christian has built up a company with about 1 million followers centered on helping others improve fitness through online training.
Ryan Casey - Ryan Casey has about 50k followers on Instagram and helps train people through Instagram DM and in person if they go to the same gym.
Justin Martilini - Like Ryan, Justin is a teenager yet still has many followers on social media and uses that to help train others as well as promote his sponsors.