I believe what they did is take some time duration to develop tolerance and another time duration to read the effects from it, and during those durations, split study participants into four group, one of which received 400mg of caffeine during both periods (caff/caff), one of which received placebo then caffeine (plac/caff), one of which received caffeine then placebo (caff/plac), and one of which received placebo in both durations (plac/plac).
Assuming tolerance and withdrawal are actually happening, you would expect the caff/plac group to be the only group experiencing both the tolerance and withdrawal. From looking at the paper, it looks like they gave 400mg of one thing (either placebo or caffeine) for 14 days, then gave 400mg of the other thing for 1 day and asked study participants to rate themselves after 24 hours. The caff/plac group seemed to rate higher on fatigue, weariness, and being tired (not sure what the distinction is between those three things) and lower on energy.
Thanks for this. Now it makes more sense. Interesting that the caff/caff and plac/plac group have levels that are identical for all four measures. As you may have noticed, coffee prices are through the roof now. I've been a heavy coffee drinker for most of my life, so I recently decided to confine it to just one cup in the morning. I'm becoming convinced that the feeling of more energy and wakefulness that caffeine brings is just an illusion. It only last for 10-15 minutes at best but thereafter leaves you feeling depleted and vacant. Also, for the addicted user, that good 10-15 minutes is only a period of relief from feeding the dependence.
Indeed. The article also really does not introduce the concepts properly. For instance, I started reading it thinking the point of the article was to discuss lessening caffeine tolerance by weaning oneself off of it, but by the end, it promotes caffeine tolerance as a net positive. Confusing.
Assuming tolerance and withdrawal are actually happening, you would expect the caff/plac group to be the only group experiencing both the tolerance and withdrawal. From looking at the paper, it looks like they gave 400mg of one thing (either placebo or caffeine) for 14 days, then gave 400mg of the other thing for 1 day and asked study participants to rate themselves after 24 hours. The caff/plac group seemed to rate higher on fatigue, weariness, and being tired (not sure what the distinction is between those three things) and lower on energy.