Fasted progression starts with repeatable movement, not an elevation threshold.
Change food timing first, repeat before extending, and introduce altitude only as a separate demand.
The earlier ladder treated fasting below 6,000 feet as the universal first stressor. The updated method begins one step earlier: establish repeatable movement in a fed or usual state, then test fasting as a single optional variable.
Fasting duration, hike duration, distance, gain, pace, load, temperature, and altitude all contribute to dose. Progression changes one primary variable while the others remain as stable as practical.
Record direct observations first. Energy stability, pace, perceived exertion, symptoms, food, fluid, and normal function can inform a decision. Ketones do not establish autophagy; completion does not establish that the dose was right.
The Engine asks whether the chosen task remains within demonstrated capacity. The Governor asks whether symptoms, medications, medical context, sleep, heat, cold, altitude, terrain, or judgment require fuel, reduction, substitution, or rest.
Use observation → inference → hypothesis → decision → revision. Define what would falsify the progression hypothesis before increasing the dose.
Carry water and rapidly usable fuel. Stop or fuel for deteriorating function; seek urgent help for chest pain, fainting, confusion, loss of coordination, severe shortness of breath, or rapidly worsening symptoms.
This page owns the progression sequence after a repeatable fed reference and an eligible fasted trial. Safety eligibility remains governed by the Fasted Hiking Safety Playbook, while mechanism questions belong to the Eating and Autophagy explainer.
This page owns the progression sequence after a repeatable fed reference and an eligible fasted trial. Safety eligibility remains governed by the Fasted Hiking Safety Playbook, while mechanism questions belong to the Eating and Autophagy explainer.
Establish a familiar fed walking or hiking reference before testing fasting.
Use an easy route, conservative duration, favorable conditions, and a reliable exit while changing only food timing.
Collect several comparable observations before increasing duration or route consequence.
Increase time or distance modestly while holding pace, terrain, load, and altitude as stable as practical.
Repeat the new dose until energy, symptoms, decision quality, and normal function form an acceptable pattern.
Treat altitude, heat, cold, external load, and higher intensity as independent variables. Do not progress by automatic stacking.
Shorten, fuel, substitute, or discontinue when the Personal World Model does not support further progression.
Where should progression begin?
With repeatable fed movement, followed by a short fasted trial on a familiar low-consequence route.
Is staying below 6,000 feet required?
No. There is no physiological cliff at 6,000 feet. The point is to avoid unfamiliar altitude while food timing is the variable under study.
How quickly should duration increase?
There is no universal schedule. Extend only after repeated comparable sessions support the decision.
Does hunger mean the session failed?
No. Hunger is an observation. The relevant decision is whether function, symptoms, safety, and the original purpose remain acceptable.
When should I add altitude?
Only after the fasting condition is familiar, and then as a separate altitude progression with its own safety plan.
What proves adaptation?
No single session proves it. Adaptation requires a longitudinal pattern across comparable observations.
Can I stop progressing?
Yes. Consolidation or discontinuation can be the correct outcome.