It is worth noting that in the single-player story mode of GTA V, completing the Triathlon challenges unlocks the "Unlimited Stamina" special ability for the character Michael. Some players erroneously believe this carries over to FiveM. It does not; FiveM uses a separate set of variables and saves independent of the single-player story progress.
: In PvP-heavy servers, infinite stamina is considered an essential feature for fast-paced combat and quick maneuvers across the map. How to Find it fivem infinite stamina
Timing considerations: