Exercise

I: Beginning to Run

I was born in the hospital to which I would return thirty years later as a medical resident. One of the last snowfalls of the year blanketed the city as my parents carried me into our small house across the street from Manor Park. Two years later my family moved to Port-au-Prince, Haiti’s capital city. My father’s work in international development and my mother’s job as a teacher kept us moving every couple of years, always leaving a place just as it became familiar. In Haiti my brothers and I practically lived outdoors. We chased each other through the house and clambered on the orange-tiled roof. We were sunburned and covered in mud from the ravine at the bottom of our garden. When my father came home from work, my brothers and I would follow him outside onto the concrete porch, and while he lifted weights, we played at exercise.

We would drive in our red Toyota Tercel the ninety kilometres to Jacmel, a beach town on the southern coast of the island. The short distance would take hours thudding over the muddy half-built roads. The ocean at Jacmel was fierce. I remember the feeling of being swept under the water as a wave crashed over me. My small body was gripped by the undertow as I struggled to my feet, and I learned to respect the ocean. We spent the nights in small concrete huts just off the beach listening to the sound of crashing waves.

My brother Sascha was born while we lived in Haiti. My mother travelled to Ottawa to deliver him then returned when he was only a few weeks old. I remember the volume of paraphernalia she brought back with her; it seemed like so much equipment for such a small person. He would grow into a tall and lean athlete, unbeatable on a bike, able to run at a blistering pace long before I took up the sport. My older brother, Alex, has a heavier build — he lifted weights and learned judo — but he would also go on to be a dedicated and fast runner.

In 1988 we moved to Bali. It was a paradise, and my parents granted me the freedom to explore. From the age of seven I was given free rein — I headed out on my bike and explored the rice paddies and surrounding villages. I flew kites and ventured down to the beach, and one day I stopped in a field under a perfect blue sky and learned to tie my shoelaces. Perhaps I didn’t venture far, but I felt I could traverse the island in complete safety.

The world seemed so big back then. In 1991, during the time of the Gulf War, I sat in class at Bali International School looking at an issue of Time magazine that detailed the types of jets and missiles deployed against Saddam Hussein’s regime. I felt a vague sense of unease knowing there was a war somewhere else in the world, but we did not have CNN, so I had only a blurry concept of what this meant.

My family moved to Tanzania when I was eight, and there I ran and raced my way through elementary school. I remember racing down the small hill next to our classroom in a cluster of boys and girls. We practised doing front flips by launching into handstands then flipping onto our feet. I felt that this was an incredible feat, but others went even further. Two of my friends — a pair of twin boys — could run into a front flip without touching their hands to the ground. Amazing us even more, they could do backflips. They were daredevils. I stuck to front flips.

In Tanzania we travelled frequently, roaming ever farther from our home in the capital city of Dar es Salaam. My parents and two brothers bundled into our white Land Cruiser and ventured north toward Kenya. We explored the Serengeti, Ngorongoro Crater, and Mount Kilimanjaro. We passed through the towns of Moshi and Arusha, which I would return to twenty years later as a medical student. One day we turned off the main road, and the tires started to churn up dust around us. My father kept driving, but with almost no visibility. The dust started to come in through the ventilation system, and I could taste the grit like sandpaper. All of a sudden sunlight streamed in the windows. We had broken through and arrived at Olduvai Gorge.

Presumably, my parents had told me about our destination earlier that morning, but it would have meant nothing to me. How could they have explained the earliest beginnings of humanity to a ten-year-old? Even today my most vivid memories of the day are driving through that fountain of sand and dirt and the darkness inside the car. But I also remember seeing a monolith of dirt and rock projecting out of the landscape with variegated strata, which to my mind represented the layers of time. Homo habilis occupied the site from nearly two million years ago followed by Homo erectus, and in the last seventeen thousand years came Homo sapiens. That day at Olduvai Gorge has come back to me countless times as I have studied biology, medicine, and the history of our species.

Olduvai Gorge embedded in me a deep and early appreciation of the fact that modern humans are the product of millions of years of evolution in the African savannah. We often hear that humans have “Stone Age brains.” Although the societies in which humans live are unimaginably different than those of our ancestors, our bodies have not changed much. As a result we find it difficult to cope with the modern world. Anxiety, for example, is said to be the consequence of primitive instincts that lead us to be always on the lookout for threats; obesity is caused by our urge to consume high fat and sweet sources of nourishment. In Olduvai Gorge the fear of threats and the compulsion to consume as much high-energy food as possible were positive adaptations; indeed, they were essential for survival. In contemporary Shanghai or New York, they are not only less useful, but they are causing epidemics of suffering and leading to premature death.

While the Stone Age brain explanation for the problems suffered by modern humans is often oversimplified, it is true that we have to accept our brains and bodies as they are and design a world that optimizes human health and well-being within the scope of those limitations. Unfortunately, we have not been very successful at doing so. As a result, most people today, adults and children, do not eat properly, nor do most get the exercise and connection with nature we all need and crave.

Living and travelling in East Africa showed me that nature is a wonder to behold; I learned, too, that it is a primal force to be respected. I remember cowering in the back seat while we drove across a flat grassy plain in Tarangire Park in northern Tanzania surrounded by hundreds of elephants. I glanced out of the window to see the herds marching serenely by. On an earlier trip to Kenya, an angry female elephant had charged us, protecting her calf from our Land Cruiser. Humans are masters of the world, but we are also fragile, anxious bipeds who do well to run for cover when confronted by a threat.

Another year we travelled south to the Selous, which was, at that time, an enormous and relatively pristine nature reserve nearly devoid of human habitation. We boarded a small motorboat that spluttered down the Rufiji River toward a pod of hippos. I felt acutely exposed in the small boat as we drifted amid these ton beasts, any one of which could have crushed our little vessel in an instant if instinct had urged them on to such an act.

That first day in Olduvai Gorge was like so many others, as I walked amid the baobab trees, boulders, and coarse vegetation. As my brothers and I played tag or raced or climbed, we were expressing the same basic urges to move and play felt by our ancient ancestors there. Every time I have returned to East Africa since my childhood, I have felt as if I have come home. Not to my home necessarily, although it does seem familiar and comfortable, but to humanity’s home. I have a chemical reaction to the earth and landscape; it is the place we were born and grew up as a species.

***

Our human ancestors evolved the ability for endurance running around two million years ago. In Why We Run, Bernd Heinrich describes a cave painting he saw on a research trip to Zimbabwe:

Painted onto the wall under the overhang was a succession of small, sticklike human figures in clear running stride. All were clutching delicate bows, quivers, and arrows.… [T]hen I noticed something more, and it sent my mind reeling. It was the figure farthest to the right, the one leading the progression. It had its hands thrown up in the air in the universal runner’s gesture of triumph at the end of a race. This involuntary gesture is reflexive for most runners who have fought hard, who have breathed the heat and smelled the fire, and then felt the exhilaration of triumph over adversity.

For Heinrich, this image served as a reminder “that the roots of our running, our competitiveness, and our striving for excellence go back very far and very deep.” When we run in nature, we reach back and touch our ancestors.

The roots of running go down to the very bedrock of our humanity. To run, we needed to walk, and to walk, we needed to walk on two legs — to become bipedal. Why and how did this happen? African apes live in trees. They are strong but slow. They have large hands, large feet, short arms — features that are important for climbing trees but are impediments to running. They are quadrupeds, living and feeding on the forest floor.

You may have seen a chimpanzee knuckle walk, resting its forelimbs on flexed hands as it moves around on all four limbs. Knuckle walking allows primates to move as quadrupeds while still being well adapted to tree climbing. However, the strongly flexing hands of chimpanzees and gorillas are not able to match the extremely precise movements of our own very dexterous fingers. Knuckle walking only allows for very slow movement; it does not make chimpanzees more agile on land. Knuckle walking wastes energy. It was an evolutionary strategy that led nowhere.

To become great runners, humans first had to become bipedal. This transition began with the last common ancestor (LCA) of humans and chimpanzees. Whether or not this ancestor was a knuckle walker is, for now, unknown. But one characteristic of this primate that is more certain is that it was built more for power than endurance. It is likely that its muscle groups were made up predominantly of fast-twitch fibres, which are well adapted for heavy lifting. It would have had more strength than Homo sapiens but less ability to cool itself, less energy efficiency, and limited ability to walk or run long distances.

Fast-forward to four million years ago and the fossil record reveals my favourite human ancestors: the australopiths. In high school, I saw an image of a small, hairy primate chasing some kind of antelope progenitor with a spear, and I read the word Australopithecus. Saying it is like having ice in your mouth. The australopiths were a large group of early hominids who lived in Africa between one and four million years ago. They were the first of our ancestors to descend from the trees and begin life on just two legs.

One million years later, a corner of East Africa echoed with the soft footfall of Lucy, an Australopithecus afarensis discovered in Ethiopia. She was a young but mature female and would have stood only three feet tall and weighed sixty pounds. She shows features of the transition to bipedalism. I have looked in awe at reconstructions of her skull, which is so small and different from our own but is at the same time so human.