Cross-country skiing
The papers behind this review describe this option; none of them states what it was measured against. It carries no evidence profile of its own.
Round-2 tier-3 flag: thin - under 4 full-text papers.
No extraction row pairs this option with a requirement, so it is not filed under a slot. Its rows name several practices at once without saying which fills what.
No extraction row describes how this option is performed. It is catalogued from the review's paper counts alone, and nothing here is written from general knowledge.
Nothing states what this option's dose measures — no library step prescribes this option and its review states no dose unit.
No row states a dose or a time for this option.
Equipment is a property of the movement and is authored, never derived from the evidence corpus (docs/research/round2/ROUND2_KNOWN_CORRECTIONS.md §1). This option resolves to no catalogue exercise, so nothing has authored it yet.
No row states a level or a prerequisite for this option.
No row states how to make this option harder or easier.
The papers behind this option report nothing on contraindications, which is not the same as saying there are none.
No row describes the setting.
No paper compares this option with another or calls it interchangeable with one.
A paper measuring one option against another does not make the two interchangeable, and it does not say which to choose. These are listed as what the papers did, and nothing here proposes a substitution.