How Far, How Fast, How Heavy? Predicting the range of an unsupported long distance trek

Roman Dial presents theory and formulae that can be used to predict the range of an unsupported trek. The mathematical models considers food weight consumed per day, base weight of gear, maximum mileage per day, and spits out estimates for duration of your trek and pack weight required to complete your desired distance - without resupply or support.

An interactive model simulator is included to tailor and calibrate the model to your own abilities and objectives.

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Read an excerpt from the article here:

The problem is stated simply; how far can you go, on foot, and self-contained? No food drops, no foraging, no wheels, no motors. Everything you need, including food, you carry on your back. How far can you go and how long will it take? We can call this your maximum range.

No doubt you will say, "My maximum range depends on a whole host of factors." And I will agree, that, yes, it depends, but it will depend on less than you think. And by that I mean the predictions will meet with observations surprisingly well and without all the messy details that most of us would insist should be included.

In some ways this question of "How far how fast?" is a variation on adventure racing. However, as far as I know, nobody has organized a competition to see what the extreme maximum range might be: 50 people toed up at the start line, the only rule that everything needed is in the pack and the race is over after all racers have run out of food and marked their distance would help answer it. I offer some predictions.

My interest in maximum range stemmed from Alaskan "wilderness racing" during the early 1980's. It was then, before the Eco-Challenge, Raid Gauloise, the Southern Traverse in New Zealand, or even Ray's Way or GoLite - that a handful of us raced across large blocks of Alaskan wilderness, mostly un-trailed, over mountains, across rivers, past bears. These were big chunks, with straight line distances between roads in the 75 to 100 mile range. And we traveled very light.

The rules for the Alaska Mountain Wilderness Classic were brutally simple: start here, go there - where "there" was 150-250 miles away - carrying everything needed, including food, with you from start to finish. No help, no roads (usually one road was crossed), no motors, no pack animals. Instinctively I knew that a heavier pack meant a slower pace, and to a competitive person, a heavier pack meant a lesser chance of winning.

Like everyone who races more than once, I discovered that weight kills speed. Not only does weight kill speed, I found that weight kills distance. And by 1984, after three seasons of wilderness racing, I'd uncovered a ruthless calculus: it appeared that every pound dropped from my back increased my daily maximum by a mile.

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Comments

[Bryan]

You say, "no foraging." Does that mean that if you eat berries along the way you will have broken the "fair means" rule?

[Roman Dial]

Luckily, there will not be any fresh berries to tempt us! The fair means rule to my mind means no motors, wheels, or animals as transport. Eating berries would probably violate the no-foraging rule.....

[Ryan Jordan]

Foraging. Not much available up there in June. Chew on willows, I guess...

The real issue, if berries were even available, is time. For huckleberries in particular, the ability to extract enough calories to be meaningful from a huckleberry bush would require quite a bit of time which might be better spent carrying a few extra oz's of food and ... walking...