# Study 000F Methods

## Core Question

Do the combined findings from `000D` and `000E` support the existence of a successful operating envelope rather than a simple place, surface, or treadmill-versus-outdoor distinction?

## Scope

This study does not try to answer every child question created by the archive.
It has one job:

- test whether `operating envelope` explains the observed pattern better than `surface category` alone

It therefore does not try to fully settle:

- cadence preservation mechanism
- ecological narrowing mechanism
- hybrid-cardio bridge function
- next-day burden mechanism
- every axis that might define envelope membership

## Evidence Families

The study was organized around five evidence families:

1. Success clustering
2. Burden boundary behavior
3. Exception handling
4. Explanatory power
5. Transferability

## Source Tables

The package uses copied source tables from:

- `000B`
- `Microstudy B`
- `000D`
- `000E`
- `000C`

The most important run-level source is the `000B` run-level dataset, which carries:

- session HR residual burden
- running share of recent activity
- total activity hours
- next-day recovery fields

## Operating Logic

The study does not define operating envelope from surface alone.
Instead, it asks whether a bounded successful-expression construct better explains:

- late successful running clustering
- strongly positive October 2025 outside-cluster burden
- the April 2026 near-zero burden exception
- the wide burden spread within the same outdoor surface label