That's the thing. It was not noticeable at the time. No heavy breathing, no pain in the legs, no sensation of "this is hard" that you get with most formal worko

That's the thing. It was not noticeable at the time. No heavy breathing, no pain in the legs, no sensation of "this is hard" that you get with most formal workouts. But I have no doubt that my heart rate and adrenaline/cortisol levels had already been elevated, enough so to disrupt the typical sleep cycle.