There's no reason to avoid caffeine. It's a very stress protective substance. Coffee with a little bit of sugar is a great way to sustain concentration far longer than you otherwise could. If one is adapted to it, it does not make one jittery.
Another lesser known chemical trick is aspirin. Aspirin boosts energy, mood, and concentration. Some days I down nearly three grams. I find it works synergistically with coffee.
One of my co-worker and one of my friends drink at least three cups of coffee in the morning alone to get the day started. The chemical tolerance they've built up scared me off.
Another lesser known chemical trick is aspirin. Aspirin boosts energy, mood, and concentration. Some days I down nearly three grams. I find it works synergistically with coffee.