WASHINGTON, Dec. 27 (Xinhua) -- Exercising twice a week may improve memory and thinking ability in people with mild cognitive impairment, according to a guideline released Wednesday by the American Academy of Neurology (AAN).

The recommendation was an update to the AAN's previous guideline on mild cognitive impairment and was published online in Neurology, the academy's medical journal.

"Regular physical exercise has long been shown to have heart health benefits, and now we can say exercise also may help improve memory for people with mild cognitive impairment," lead author Ronald Petersen, director of the Alzheimer's Disease Research Center at Mayo Clinic said in a statement. "What's good for your heart can be good for your brain."

Mild cognitive impairment, a medical condition that is common with aging, has been linked to problems with thinking ability and memory.

Patients may struggle to complete complex tasks or have difficulty understanding information they have read, and there is strong evidence that the condition can lead to dementia.

But some people with mild cognitive impairment never get worse, and a few eventually get better.

The academy's guideline authors developed the new recommendation after reviewing all available studies on mild cognitive impairment.

Although long-term studies have not been conducted, six-month studies suggest twice-weekly workouts may improve memory, they found.

Petersen encouraged people to do aerobic exercise: Walk briskly, jog, whatever you like to do, for 150 minutes a week -- 30 minutes, five times or 50 minutes, three times.

The level of exertion should be enough to work up a bit of a sweat but doesn't need to be so rigorous that you can't hold a conversation, Petersen said.

"Exercising might slow down the rate at which you would progress from mild cognitive impairment to dementia," he said.

The guideline did not recommend dietary changes or medications, saying that there are no drugs for mild cognitive impairment approved by the U.S. Food and Drug Administration.

Worldwide, more than six percent of people in their 60s have mild cognitive impairment, and the condition becomes more common with age. More than 37 percent of people age 85 and older have it.

"We need not look at aging as a passive process; we can do something about the course of our aging," Petersen said. "So if I'm destined to become cognitively impaired at age 72, I can exercise and push that back to 75 or 78. That's a big deal."