In 1926, English physiologist Archibald Vivian Hill declared in a Scientific American article, “Our bodies are machines, whose energy expenditures can be closely measured.”*
This mechanistic view of our physical selves permeated the beliefs of the twentieth century. “Body parts wear out, like tires” we were told, “you only have so much energy to expend- it’s like gas in a car. Once the gas is out, you will no longer be able to keep going,” endurance athletes believed.
The problem with this is pain can exist without structural damage and structural damage can exist without pain, which means in the presence of structural damage people can often still perform everyday activities in a pain free manner.** Unlike tires, which need to be replaced if they get a hole in them, our original parts can not only take a little bit of wear and tear, our structures adapt to the demands placed upon them, getting stronger and better able to withstand force. If an engineer were to develop a tire that adapted to the demands of the terrain and became more durable over time, he would be considered a genius (and probably be worth a lot of money).
In a similar manner, the ability to endure is dependent on a variety of factors, including how well rested you are, your psychological state, and, yes, your nutritional state. However, it’s more than that, as tales of survival remind us. (Google “survivors lost in the woods.” You will find amazing stories of people lasting far longer than they physiologically “should” be able to keep going).
We are multi-faceted organisms and are physical capabilities and experiences are predicated on much more than our physical parts. If we stop viewing ourselves as machines that break, we will tap into a deeper sense of resilience.
*From Alex Hutchinson’s book, “Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance.”