As I drove from New York City to rural Deer Lake, Pennsylvania, I tried to imagine what I would find there. I was on assignment for New Times magazine to take some photographs at Muhammad Ali's training camp that the art director could use to illustrate a piece they had in the works on Ali's preparation for the 'Rumble in the Jungle' in Zaire, Africa. A global audience was fixated on the fight that would determine the next world heavyweight boxing champion.

I had never been to a boxer's training camp. In fact, aside from movies, I knew very little about the 'sweet science'. Educated by Hollywood films, I supposed thick, menacing men in ill-fitting suits would be lurking about the premises with no clear purpose, the left side of their suit coats bulging near the heart.

What I did know was that Muhammad Ali (né Cassius Clay, Jr) was the most recognisable human on the planet. I knew that he was an extraordinary individual whose personality encompassed multitudes. Often he was loud, pushy, and arrogant – a clown, whose provocative antics were always surprising. He was also an outspoken voice for civil rights with a global perspective. Like everyone else, I knew that he had become a Muslim and was a follower of Elijah Muhammad. I knew that he had been arrested when he refused the military draft at the height of the Vietnam War, that his World Heavyweight Championship title had been stripped from him, and that his draft case had ultimately been decided in his favour by the United States Supreme Court.

Following my instructions from the main highway I spotted a sign with an arrow: 'Ali's Camp'. I found the motel where a reservation had been made for me and I retired early. At 4.30am the next morning I was awakened by an insistent pounding on the door. A voice shouted, "Grab your pants and your camera! The Champ is running!"

There were four men in the car. I squeezed into the back seat. Soon we were driving very slowly on a rural black top past trees and cornfields, past a letterbox on a wooden post. Nobody around. Up ahead was Muhammad Ali dressed in grey sweat pants and sweatshirt, army boots on his feet. I scrambled out of the car and started shooting Ali from behind as he jogged. In the very first shot Ali's breath is visible in the early morning cold. He is running along the right edge of the road toward the awesome blast of the rising sun.

Over the next five miles I was in and out of the car shooting Ali as he jogged. A cow in a field of daisies watched as he passed. In the empty countryside, the former heavyweight boxing champion of the world raised his arms high in victory.

In the shot Ali's breath is visible in the early morning cold. He is running along the right edge of the road toward the awesome blast of the rising sun

At the end of the run Ali jabbed the air and danced in the road, cooling down; with me shooting all the while. We had not spoken. "Get this," he said. I raised my camera positioning for a vertical. Ali pulled up his sweatshirt and the rubber liner inside it. As I shot, water poured out. "It's called letting out the sweat," he said.

At that moment I realised that Ali got me. He understood that I was not interested in him posing and mugging for the camera, but in observing the reality of his preparation for the pivotal fight just a month away.

In the 48 hours that I was there, Ali toured a home for old people, gave an exhibition match at a local high school, worked and joked with the construction team who were delivering boulders, shared his poetry with a visiting actress and writer, relaxed and entertained local visitors in a log cabin, worked the punching bag while the black power activist Stokely Carmichael looked on admiringly, performed slight of hand tricks in the gym's ring, and played straightman as showbiz magician Doug Henning linked five solid metal rings to form a chain (a trick that I had performed myself as a child magician).

Ali told me no one had ever taken so many pictures of him. It turned out to be 33 rolls – 1,080 individual frames in two days.

The atmosphere and activities at Fighter's Heaven were designed as an antidote to the gruelling exertion and boredom of training and to nourish Ali's image as champion. I believe everything I saw there was part of Muhammad Ali's imaginative formula for success in the looming fight against the brutal, undefeated George Foreman.

Muhammad Ali: Fighter's Heaven 1974 – an exhibition of Peter Angelo Simon's photographs from this trip – runs until 28 May 2016 at Serena Morton II, 345 Ladbroke Grove, London W10 6HA. Muhammad Ali: Fighter's Heaven 1974 is published by Reel Art Press in July 2016 (£40). For further information:;