BUFFALO, N.Y. (WIVB) — Your morning cup of coffee may not be giving you the jolt of energy you’re expecting. This is especially true if you’re tired.
New research from the U.S. Military confirms that caffeine no longer works after a few nights of sleep deprivation.
A research scientist at Walter Reed found caffeine no longer improves alertness or mental performance after a few nights of poor sleep.
The doctors looked at 48 healthy volunteers. They limited them to five hours of sleep for five nights in a row.
People took either 200 milligrams of caffeine or a placebo, then doctors tested their skills.
The study found that after restricting sleep to 5 hours per night, caffeine use no longer improved alertness or performance after three nights.
You can read the researchers’ study here.