Tired-al waves tend to hit an individual suddenly and unexpectedly, particularly after prolonged periods of work or fun-having. Many people describe how they feel quite energetic in one moment and the next they are hit by a wave of exhaustion. This is a tired-al wave.
John; Dude that marathon was awesome, I could do it all again.
Jim; No probs dude, let's go!
John; Oh no, wait, major tired-al wave...sorry I'm going home