This is the 11993rd most frequent Spanish word.
incontrolables
Uncontrollable.
The word 'incontrolables' is used here as an adjective to describe 'emociones', implying they are beyond control.
Las emociones en situaciones estresantes a menudo son incontrolables.
Emotions in stressful situations are often uncontrollable.
The word 'incontrolables' qualifies 'retos', suggesting the challenges are such that they cannot be managed or dominated.
Los jugadores enfrentaron retos incontrolables durante el partido.
The players faced uncontrollable challenges during the game.
'Incontrolable' here is singular and used to describe 'la velocidad', indicating it refers to its unmanageable nature.