I am struggling with how to describe this but curious if others experience it. When my DD gets into doing something, she just cannot stop, she will do it well beyond the bounds of sheer exhaustion and even then she doesn't want to rest. For example yesterday we got a random nice winter day and she really wore herself out playing outside, which should be a good thing, good muscle strength, sensory integration, sunshine fresh air ect but then today she was obviously still very tired but she just cried and tantrumed all day and refused to settle into any of her favorite calm activities. If I can predict from past experiences, I know this will go on for several days, she will sleep poorly, get up too early and be exhausted and cranky and inattentive all day. Then she will crash and do nothing for several days but watch tv and color. Then in about a week she will get back to normal.