For much of his career, boxing great Muhammad Ali was convinced that his brain wouldn’t be affected by the thousands of powerful, crippling blows he received from his opponents, says the author of a recently released biography on the iconic fighter.
“He kept saying it wasn’t going to happen to him, that he wasn’t gonna get brain damage,” Jonathan Eig, who spent four years conducting nearly 500 interviews for his book Ali: A Life, tells PEOPLE.
“In fact, he encouraged his sparring partners to hit him in the head. He believed he could build up resistance to shots to the head, kind of like calluses.”
Over the course of 640 pages, Eig chronicles the life of the three-time heavyweight champion whom, he says, “made people really rethink what it meant to be an athlete. He changed the country and the world. There had never been an African-American athlete who spoke up the way he did and demanded to be treated as more than an entertainer.”
But it’s Ali’s struggle with neurological damage, painstakingly detailed by Eig, that remains a particularly poignant part of his life story.
In an effort to pin down exactly when the boxer first began to exhibit symptoms of brain damage, the author interviewed speech scientists, statisticians and even Ali’s longtime doctor, Ferdie Pacheco.
“Ferdie told me that he thought he first saw signs of real brain damage as early as 1971 — when he was 29 — after Ali’s fight with Joe Frazier,” says Eig.
Together with two statisticians, Eig reviewed footage of all of Ali’s fights and determined that he “was probably hit about 200,000 times” during the course of his 61-fight career, which ended with his retirement in 1981. Roughly half of those blows, he estimates, were to the head.
“He absorbed way more blows than the average fighter because, as he got older and slower, part of his strategy was to allow his opponents to him,” says Eig. “He thought he could wear down his opponents by letting them punch him in the head, then wait until the late rounds when they’re tired and beat them.”
Eig also studied film and video footage of Ali’s numerous interviews with speech experts that revealed he had begun to lose the ability to speak clearly in the early 1970s, exactly as Pacheco had told him.
“We studied Ali’s speech patterns over the years and you could see Ferdie was right,” says Eig. “His voice was slowing down and turning softer and softer and with every fight it grew worse and worse. Between 1970 and 1980, he’d begun speaking 26 percent slower. And you can see that after individual fights, his speech rate would decline, then begin to recover until he’d fight again — then it would go back down.”
By 1977, Pacheco was so concerned about Ali’s condition that he recommended Ali retire from the sport. The physician ended up leaving the boxer’s camp when he refused.
A few years after his retirement, Ali was diagnosed with “a cluster of symptoms that resemble Parkinson’s Disease,” known as Parkinson’s Syndrome, which his doctor believed were caused by numerous blows to the head.
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When he took his medications, it helped control his shaking, but as the years passed he “got slower and slower” and then his voice disappeared as he began to have more bouts with infections and pneumonia. In his final years, Ali found it increasingly difficult to get out of the house, but loved to Skype with his grandchildren and watch himself on YouTube.
“It was a sad decline,” says Eig of Ali, who died in 2016 at the age of 74. (No autopsy was ever conducted on his body.) “But he always said that, given the same set of choices, he’d repeat his decision to become a boxer.”
“Boxing was obviously what made him Ali,” Eig adds. “I’m not sure what he would have been without it.”