I'm currently on a 6a-2p shift and commute roughly 70 miles each way. I wake up at 4am and usually am in bed between 9-10pm. If I drink coffee WITH caffeine anytime after 4-4:30 (I get home around 4ish) it messes with my sleep that night.
Bottom line; does decaf have the same benefits as a pre-wo drink?
On a sidenote; black coffee helps me through my IF days IMMENSELY.
Your best bet is to take 200mg of pure caffeine before workouts. The acids in coffee can elevate cortisol for up for 14 hours. Studies showing the benefits of caffeine on metabolism were done without the excitotoxins and optionally milk solids/sugars normally ingested with coffee. (*Master Your Metabolism, Jillian Michaels, 2009)
Another thing I probably should have mentioned: Jillian always recommends taking a small dose of aspirin with caffeine (like 125-150mg). I can't find the reference right this second, but it apparently reduces some of the negative side effects and enhances the positives. Her line of metabolism boosting supplements are mainly caffeine, aspirin, and vitamin C.
I would think that the caffeine is the important part of the coffee for PWO purposes. I do also believe in the placebo effect and you might still think you're getting that kick from decaf but the real stimulant is in that caffeine. I do one espresso before lifting.
No decaf! I am another who drinks one espresso before my weight workout. The idea is that I get one more rep that I wouldn't otherwise have gotten, and so am able to make the workout a little more intense, and cause a greater stress and hopefully a commensurately greater adaptation. In the days when I used to be a distance runner, caffeine was more of a motivational tool ... on a cold, rainy day it was often the only way I was going to get out the door for an 8 mile run, especially in the morning.
Forrest had an interesting comment about using pills instead of coffee in order to reduce cortisol.