How many cups of coffee do you have a day? It's not a stretch to say that caffeine is the world's most popular drug. A recent study found that 85 percent of American adults consume the drug in some form every day, but when and how frequently should we be taking a caffeine hit to get the best effect from it?
A new study conducted by a US Army research center has developed an algorithm that reportedly can optimize an ideal caffeine dosage strategy to maximize alertness when experiencing lack of sleep. The research is led by Jaques Reifman, director of DoD Biotechnology High Performance Computing Software Applications Institute and the Telemedicine and Advanced Technology Research Center at the U.S. Army Medical Research and Materiel Command.
"We found that by using our algorithm, which determines when and how much caffeine a subject should consume, we can improve alertness by up to 64 percent, while consuming the same total amount of caffeine," says Reifman. "Alternatively, a subject can reduce caffeine consumption by up to 65 percent and still achieve equivalent improvements in alertness."
The system can generate personalized caffeine dosage suggestions based on a user inputing sleep and caffeine intake data, as well as completing a series of psychomotor vigilance tasks (PVT). These PVTs are essentially simple response time tests, conducted at various times over a couple of days and logged against a person's sleep and caffeine-intake schedule. This data is used by the algorithm to calculate an ideal dosage strategy for the individual.

While the technology has obviously been developed with military applications in mind, the US Army is currently licensing the software with a view on producing a commercial smartphone app for public use. The proposed app would learn an individual user's habits, as well as potentially logging fitness tracker data, to help optimize the best caffeine schedule for peak cognitive timing.
An open source version of the system, called 2B-Alert, is currently available offering a limited demonstration of the technology based on older research. This sample system delivers results based on sleep and caffeine-intake inputs but doesn't deliver personalized dosage strategies as it doesn't include PVT data.
"Our algorithm is the first quantitative tool that provides automated, customized guidance for safe and effective caffeine dosing to maximize alertness at the most needed times during any sleep-loss condition," says Reifman.
The new study was published in the Journal of Sleep Research.