Coffee pick-me-up: What amount is perfect?

Suppose you are a soldier. You’ve gone days without much sleep, but you must stay as sharp as possible because lives could be at risk.

That’s just the scenario the U.S. Army considered when they developed an algorithm for the perfect amount of coffee for maximum alertness.

Senior research scientist Jacques Reifman, U.S. Army Medical Research and Materiel Command, helped develop the algorithm that predicts caffeine dose based on sleep patterns, according to The Wall Street Journal.

An 8-ounce cup of weak coffee has about 100 milligrams of caffeine. A strong cup has 175 milligrams.

About 40 percent of soldiers sleep no more than five hours a night, less than the seven or more hours recommended by the Centers for Disease Control.

Meanwhile, the average civilian sleeps about 6.8 hours a night.

The algorithm finds that a generally well-rested person, in this case a soldier, who gets five hours of sleep one night could drink eight ounces of weak coffee upon waking at 7 a.m. and the same at 9 a.m. The soldier then would be just as alert as a person who slept eight hours.

While eight hours of sleep produces high levels of alertness all day, a person who sleeps no more than 6.8 hours each day for a week would need 200 milligrams of caffeine at 7 a.m. and at 9 a.m. to achieve the same alertness.

The full mathematical model with a working name of 2B-Alert will be online in app stores in a few months.