# Study 000E Discussion

This study matters because it gives the selective-expression model a cost structure.

`000D` argued that the system became more selective about where and how successful running could be expressed.

`000E` now shows that this was not only a descriptive environmental preference.
It also appears to have carried burden consequences.

The strongest reading is not:

- outdoor is bad
- treadmill is good
- one run was harder

The stronger defensible reading is:

`the narrowed successful context appears to protect session-level burden, and leaving that context raises it`

That framing matters.
If the paper is reduced to treadmill versus outdoor, it becomes smaller and more niche than the data supports.
If it is framed as successful context versus outside successful context, it becomes broadly relevant to altered or constrained systems that may also need a preferred operating environment.

That makes the selective-expression model more meaningful.
It is no longer only about where running happened.
It is also about what internal cost was attached to leaving the stabilized expression zone.

## Why this is valuable

This bridges:

- adaptation
- mechanics
- ecology
- physiology

That makes `000E` one of the most important follow-on studies in the program.

## What remains open

This study still leaves one major follow-up question:

- does next-day recovery burden also rise as cleanly as session-level burden, or is the outside-context cost mainly immediate?