From LSWiki

Class: Physical Conditioning Skills
Attribute: Vitality
Pedagogy: Physical Training
Practitioner Term: Possessor of Stamina

This skill represents the physical conditioning involved in increasing one's endurance.  The higher this skill, the more one's
endurance will exceed that which anyone of the same level of health and vitality would possess.

Development Information: The stamina skill was created by Chaos; the source code was last updated Tue Mar 15 02:21:26 2016.

Trainers

Wandering: Damon
Losthaven: Raelan Jax
Obsidia: Goth
Sinbyen: Primbal
Skarlan: Badlokk
Association required:
Losthaven Guard: Durit Kolbad
Maidens of the Spear: Sulin
Sodality of the Nine-Spoked Wheel: Grendal
Guild required:
Aisenshi: Musashi
Battleragers: Borulien
Brute Squad: Fezzik
Coven: Lynda Xenetha
Elflords: Celeborn
Hawkmen: Katar
Knights of the Round Table: Sir Lancelot
Nizari: Hasan Wanders
Ordo Ignis Aeternis: Aedryl 
Ordo Ignis Aeternis: Iklam wanders
Shapeshifters Maramar
Verynvelyrae: Sirinil
Zetesai: Linp
Quest required