Are you using and abusing caffeine? If so, help is at hand. Researchers from Penn State University in the US have developed Caffeine Zone, an app to help determine when caffeine may give you a mental boost and when it could mess up sleep patterns.
Having between 200mg and 400mg of caffeine in your bloodstream - a Starbucks grande latte has 150mg - will put you in an optimal alertness zone, according to the researchers who analysed peer-reviewed studies. But it can linger in the bloodstream, and with levels above 100mg, drinkers may experience sleep problems.
Users of the app can key in how much caffeine they drank, or plan to drink, when they plan to drink it, and how fast they drink it.
The app will then plot how it will affect them over time, and help determine optimal caffeine habits.
The researchers - who reported their findings at the Augmented Cognition International Conference in Orlando, Florida, last year - say people who drink too much caffeine too quickly may face other problems, such as nausea and nervousness.
How much do you know about caffeine? Test yourself here.
1. What is caffeine's medical name?
2. How long does it take the body to rid itself of just half the caffeine consumed?
a. One hour
b. Six hours
c. 12 hours
3. Which illegal drug has an effect similar to caffeine on the body?
4. In general, which of the following plants contains the most caffeine?
a. Tea leaves
b. Cocoa beans
c. Arabica coffee beans
Answers: 1. a; 2. b (if you drink a Starbucks grande latte at 3pm, about 75mg will still be in your body at 9pm); 3. c; 4. a (as high as 5 per cent caffeine content; cocoa beans 0.2 to 0.4 per cent and Arabica about 1 per cent)