E0 (Baseline energy per distance)

Definition

In TRIPS, E0 is your baseline energy-per-distance anchor.

In plain language, it represents the energy cost of your economical flat-ground walking baseline.

That means E0 is meant to describe a controlled reference state, not the full complexity of real trail travel.

So E0 is not:

your total daily calories
your steep-uphill energy cost
your route-average calorie burn

It is a baseline anchor that helps TRIPS interpret movement cost from a consistent starting point.

Why E0 matters

Backpacking energy use changes with terrain, pace, load, and trip conditions.

TRIPS still needs a stable baseline reference underneath those changing conditions.

E0 is part of that reference.

If it is set too low, routes can look less demanding than they really are.

If it is set too high, routes can look more calorically expensive than they should.

So even though E0 is not something most users should obsess over, it still matters.

Where the default comes from

TRIPS gives users a derived default instead of forcing everyone to enter a custom baseline energy number.

That default is based on body size, which is a reasonable first approximation for many users.

This is why E0 often changes when body weight changes, unless you deliberately override it.

The important user-facing point is:

the default is meant to be a practical starting estimate
not a precise personal measurement

What makes a good E0 value

A good E0 value should be:

tied to a controlled flat-ground baseline
believable
repeatable
conservative enough to represent your normal economical walking state

Good evidence:

a treadmill-style anchor test
a repeatable flat-ground walking test with believable energy data
leaving the default alone when you do not have stronger evidence

Weak evidence:

a full-day activity calorie total
a steep-route average
a number chosen because it makes the route outputs look nicer

Relationship to S0 and hrS0

E0 is meant to be read together with:

S0, your baseline speed anchor
hrS0, the heart rate associated with that baseline

Those three anchors are supposed to describe the same general locomotion state.

That is why overriding one of them casually can make the overall anchor picture less believable.

Default versus manual override

For many users, the default is the right starting point.

That is especially true if:

you have never run a controlled treadmill-style anchor test
you do not trust the energy estimates from your past device data enough to anchor the model
you are still working on the bigger planning decisions like route segmentation, hiking time, and effort intent

A manual override makes more sense when you have a strong reason to think the default clearly misrepresents your baseline locomotion economy.

What E0 is not for

E0 should not be used as:

a route-output tuning knob
a food-planning shortcut
a substitute for better trip-structure decisions

If the route looks wrong, the answer is often:

route segmentation
effort intent
hiking-time limit
altitude assumptions

before it is E0.

Practical advice

For most users:

leave E0 on the default at first
override it only when you have strong evidence
make sure the value reflects your normal economical baseline, not an idealized or flattering self-image

The best question to ask is:

What baseline movement cost best represents my normal, repeatable, flat-ground walking economy?

Notes

E0 is a baseline energy-per-distance anchor.
The default is intended as a practical estimate, not a precise personal measurement.
E0 works best when interpreted together with S0 and hrS0.
Most users should leave the default alone unless they have better evidence.