I am going to have a great workout.

Great tends to get measured in weight moved or minutes run, which is the wrong instrument on most days.

On four hours of sleep, after an argument in the kitchen before leaving the house, turning up and doing something moderate is a great workout. The numbers were never the point on a day shaped like that one.

Judge it by what you brought rather than by what got shifted. Some mornings the whole achievement is that you came at all, and that session counts for more than the ones where everything felt easy.