Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance

by Alex Hutchinson

In a wide variety of human activity, achievement is not possible without discomfort.

The limits of endurance running, according to physiologists, could be quantified with three parameters: aerobic capacity, also known as VO2max, which is analogous to the size of a car’s engine; running economy, which is an efficiency measure like gas mileage; and lactate threshold, which dictates how much of your engine’s power you can sustain for long periods of time.

To their frustration, physiologists have found that the will to endure can’t be reliably tied to any single physiological variable.

endurance is “the struggle to continue against a mounting desire to stop.”

What’s crucial is the need to override what your instincts are telling you to do (slow down, back off, give up), and the sense of elapsed time. Taking a punch without flinching requires self-control, but endurance implies something more sustained: holding your finger in the flame long enough to feel the heat; filling the unforgiving minute with sixty seconds’ worth of distance run.