How to make Stamina fade in after NOT using Sprint

So currently I have an simple Sprint system and a pretty complicated stamina system, it works fine but however, I don’t know how to make the Progress Bar (Or the Widget) to fade in after the player has not used Sprint after some seconds, non of the Sprint and Stamina Tutorials say how to make the widget fade in, any help please?

Screenshots of Sprint, Stamina (In Pawn and in the Progress Bar)

don’t focus on it being a “bar” ( it is just an element of the widget )
so your question would be better phrased as “how to fade in/out a UI Widget Element”

UE4 tutorial: Widget fade in/out - YouTube (it is a text on screen with no voice, and the music is higher pitch and repetitive, so probably best to mute immediately)

Mechanically the fade should probably happen on a delay when the bar is full. if your stamina is a float then remember don’t check for if it is == Max check if it is nearlyEqual(Max) or greater then a value that is >(Max-.001)