When one glances at the life and achievements of Arnold Schwarzenegger, the Austrian seems like a self-made man. From immigrating to America with barely any money to his name to becoming a global icon, Schwarzenegger worked tirelessly to achieve his dreams. However, the seven-time Mr. Olympia himself admits that he is not self-made and credits the people who taught him some of the most valuable life lessons for his success. One such individual was one of his childhood mentors, Alfred, A.K.A. Fredi Gerstl.

The lessons Gerstl taught have stayed with the Austrian Oak. Now at 75, the bodybuilding icon is sharing those lessons with other people, inspiring them to work toward their goals. So when a fan quoted Schwarzenegger’s newsletter, the former Mr. Universe revealed who taught it to him.

Training goes beyond lifting weights in the gym

While the Hollywood icon’s newsletter focuses on fitness, it’s not just physical fitness. From exercise and diet to mental health and training the mind, the 75-year-old has taken a holistic approach to wellness. With over 300,00 readers, many fans often tweet about the former champion’s newsletter on Twitter, and Schwarzenegger even replies to many of them.

On May 1, a user quoted one of Schwarzenegger’s statements from the newsletter. “I think that social media gives everyone a megaphone when what many people really need is a mirror,” read the quote. “This is one of many things that I love about @Schwarzenegger’s newsletter. Showing how to be strong in heart and mind, not just the body,” the Arnold’s Pump Club subscriber captioned his post.

Schwarzenegger saw the post and revealed he learned the lesson from someone else. “One of my earliest mentors, Fredi Gerstl, said we had to train our minds like we trained our bodies,” he wrote. While Alfred Gerstl died in 2016, Schwarzenegger is still passing on his mentor’s knowledge to everyone who reads his newsletter.

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So who was Alfred Gerstl, and how did he inspire Schwarzenegger?

The man who Arnold Schwarzenegger called his foster father

When Schwarzenegger was still a boy, he befriended Karl Gerstl. Gerstl noticed Schwarzenegger’s love for exercise. Born in 1923, Alfred Gerstl joined the Austrian resistance movement during the second world war. Gerstl realized Schwarzenegger’s potential and took him under to help them train in sports in exchange for learning about history.

“I gathered the young people together for sports, but the condition was they had to listen,” said Fredi Gerstl when he was 80, according to a report by L.A. Times. Besides teaching young boys like Schwarzenegger about history, tolerance, and the dangers of anti-semitism, Fredi Gerstl encouraged Schwarzenegger to pursue bodybuilding, something his father never did. When Gerstl died in 2016, Schwarzenegger tweeted, “My foster father is no longer with us, but his legacy lives on in those he touched.”

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