I just wish articles like this would lead with a tiny bit of research. The web is flooded with "here's how I think you can work better" articles, but very few go beyond personal anecdotes. As such, many of them are just not that useful.

Here are few things that would've been beneficial in giving a better foundation to this article - it would've been a much better starting point for actually taking action, for one thing.

BRAC/ultradian rhythm cover the basic idea of a cyclical nature of focus.

Basic neurological effects of caffeine and withdrawal cover the idea that caffeine is a zero-sum game.

The Hawthorne effect[1] covers the idea of "Macro-caffeine"

There are quite a few case studies[2] to support the idea that stress reduction improves productivity.

[1] http://en.wikipedia.org/wiki/Hawthorne_effect [2] http://www.amazon.com/Preventing-Stress-Improving-Productivi...