Does 'rest before crash' pacing advice even work?

ok so everyone talks about the discipline of resting before you hit PEM. i genuinely tried taking naps every few hours last week just to be proactive. it was useless.

the fatigue and brain fog were already there, like a baseline hum that no amount of napping fixed. it makes me wonder if pacing isn’t really about energy input/output, but maybe something more complex with my dysautonomia or POTS flares. does anyone else find their crashes aren’t tied to activity time at all?

what’s the actual trigger then?