John Seine was born in West, Massachusetts, and began to practice bodybuilding in 1989, when he was less than 13 years old. His father brought home a bench and a lot of heavy objects, which became the original fitness equipment of the Seine. Senna said: "Even though they were the worst equipment, for me at that time, they were my golden gym. In those two years, I used them to train until I couldn't make progress. I went to a regular gym. "

After that, the Seine began to read a lot of fitness magazines and follow the fitness. He said, "I admire bodybuilders like mike franks, Lee Priest and Dorian Yates. I posted a picture of mike franks on the wall. If you go to my father's house now, you will still see that painting on the wall of the room where I lived. " The Seine got a lot of inspiration from these people. In fact, Senna made a choice between baseball and bodybuilding in high school. High school hard ball said to him, "either stop bodybuilding training or stop playing baseball." The Seine still clearly remembers the choice of that day. "I weighed myself and walked straight into the gym."

1995, the Seine took part in a bodybuilding competition and won the championship of the junior group. Two years later, he won the junior group championship and the whole group championship in a national bodybuilding competition. After graduating from college, the amateur bodybuilder decided to develop in the west. 1999 After coming to Venice, he took part in two bigger bodybuilding competitions: Max Natural Bodybuilding Competition and Iron Man Bodybuilding Competition. At that time, he weighed 226 pounds and won the runner-up in both competitions.