Letter Re: Calories and Cross-Country Travel

Traveling in the aftermath of a societal collapse will become more difficult without the use of a motor vehicle, which is why you hopefully live near a water source. It is easy to visualize how after a collapse how one
could move around locally. Whether or not what one is planning on doing locally is energy efficient or not, to some degree, will not matter as there is not very much distance that needs to be covered. If
however you need to move over long distance how efficient the travel is becomes much more important. Lets look with some detail at examples.

For the following examples, I am using a 30 year old, 170 pound male. For others the absolute numbers will be off, but the relative energy use will still be the same. i.e. a 110 pound 60 year old women will still be more efficient biking then running.

Today we are used to walking out to the car, getting in and going where we want. We can sit down (77 calories per hour) and travel at 65 miles per hour. While driving it only takes 1.2 calories to travel a
mile. That is not very much at all. Bikes seem to be a common theme in plans to move around after a disaster, and we all know they are fairly easy to go long distances on. What do the numbers tell us? At a reasonable 14 mph it takes about 50 calories to move a mile. Comparing biking to moving around in a car and the car is more then 40 times more efficient! It is easy to see why cars are so popular.

Below is a table showing the energy use for several ways of getting around. What we can see is that moving around on wheels is awesome! Biking and Rollerblading are very efficient, as well is being fairly quick ways to cover a lot of ground.

Go get yourself a bike and maintain it well and you will be able to move around if you can not use your vehicle. But a bike is a pain to haul around everywhere. A set of inline skates can sit in your trunk and barely be noticed along side a good set of hiking boots. Once again we see that there is some trade offs to be made between money, gear and capabilities.

Getting back to the real point, what does this mean when moving long distances? Well the point is that it takes a very large amount of energy to move around. How much energy would it take to travel, say
100 miles? To illustrate that lets use how much food one would have to use to travel that distance. The most energy dense food that we have is fat. Butter is a good example (as is the body fat around your waist). A
pound of butter contains about 3,200 calories.

The below table shows how many pounds of butter (or fat) that one would need to use along the course of their journey to replace the calories they burned. I was surprised at just how much food [Expressed in terms of “pounds of fat equivalent”] is required to keep a person going over these distances. Also not sure where one is going to be able to pack that much food on a bike or a pack when trying to move that far.

What we can see from this is that moving around after a collapse will be very energy intense, and will require trading with others and logistics beyond “I will carry it all by myself”. This in itself is a good argument to shelter in place and keeping cash and small silver pieces on hand.