Supposedly, the number of adenosine receptors in your brain increases over time with caffeine consumption, creating a tolerance to caffeine.

I've read articles [1] which suggest that cycling off caffeine for 7-12 days helps reset the number of adenosine receptors to the baseline.

[1] http://www.smithsonianmag.com/science-nature/this-is-how-you...

There is a limit to how many receptors you can have, which limits how much "wakeup" coffee can produce. Once you hit the limit and fill them up, the only affect you get from more coffee are the negative problems. I vaguely remember it being like 400mg of caffeine or something like that.

400mg is about 3-5 cups of coffee a day depending on the roast.

Except at Starbucks, where their coffees are large and strong!

Tall 260mg Grande 330mg Venti 415mg

Venti=20oz, a 'cup' of coffee is typically considered to be 5-6 oz, so the numbers still line up.

It's also three shots (by default) making the lining up even clearer.

I've always thought that changes to receptors are how tolerance to any stimulant works.

I go cold-turkey every once in a while. I've just come off a 12-day abstinence, which was prompted by an eyelid twitch that I couldn't get rid off with simple sleep. Dropping caffeine did the trick.

The best part is the first morning coffee after a long abstinence: you feel wired, motivated and productive like you've never been before.

My observations seem to differ. Every now and then I slip into increasing my dose. But, for 90% of the time I drink one shot of espresso in the morning. It keeps me alert for most of the day. When I feel a bit bored or lazy after lunch, I'd have another one. If I keep doing that for a week, I realise the days when I don't I get particularly sleepy and low energy. 3 days after sticking to morning coffee only reverts me back to previous energy levels. I'd say if you are disciplined with your dose, it helps just the same as it did when you started drinking it.