The world will never stop drinking coffee (and caffeinated beverages), much like it'll never cease investigating supposedly healthier substitutes. Whether you're trying to swear off the stuff, or just looking for something to alternate with, there are things you can try -- from quaffing different potables to more physical activities.
Fast Company's Lisa Evans has compiled a list of popular replacements, though how easily you'll be able to execute them depends on the flexibility of your workplace.
The caffeine content of green tea is well-known, so it's no surprise it appears on the list as one of the alternatives, though the better options -- including taking a break, or even a nap, require the ingestion of nothing at all.
One of the more surprising tips is to work in a warmer environment. Contrary to dumping large amounts of cold water on oneself to get yourself firing, switching on a heater may be the best way to boost alertness:
That chill you feel in the office may be causing your productivity to drop along with your temperature. Cornell University researchers found employees working in offices with low temperatures (of 68 degrees [20°C]) committed 44% more errors and were less than half as productive than employees working in a warm office (of 77 degrees [25°C]). When the body's temperature drops, it uses up energy to stay warm. This leaves the brain with less energy to concentrate or to be creative.
Coffee alternatives that are better for productivity [Fast Company]