I'm trying to reduce my dependence on caffeine from needing ~160mg in the morning to needing 80mg. My strategy is to slowly reduce my intake, dropping maybe 20mg every 3 days. So far so good.
But sometimes I feel tired later in the day, and also want caffeine. So I have 80mg more, 10 hours after the morning 160mg. Is this going to screw up my attempt at tolerance reduction?
The argument for Yes: Daily caffeine intake is what matters. You can't reduce yourself down to needing less than 160mg in the morning by taking 240mg a day.
The argument for No: The important thing is the max amount of caffeine in you at any given time. Since the half-life of caffeine is between 1.5 and 9.5 hours (with a middle guess of 5 hours), by evening, you only have 160mg * 0.5 * 0.5 = 40mg in your system. Adding 80mg brings you to 120mg. This is less than the 160mg max dose your body is used to hitting, so it's not a big deal. As long as you keep the maximum caffeine in your system below 160mg, you can keep reducing your tolerance.
Which of these arguments is more right? Or is there a third view of the situation, better than either?