New Evidence for Body and Brain Benefits of Walking
Even a little activity helps, but more is better.
Science continues to prove Hippocrates right when he said, "Walking is man's best medicine." If you're beginning to lag on your New Year's resolutions, or that Fitbit you got for Christmas is gathering dust, a trio of recent studies provide incentive to get up off the couch and lace up those walking shoes.
"We all have heard it before, but evidence is continuing to mount regarding the dose-response benefits of physical activity," says Jennifer M. Sacheck, PhD, an associate professor in Tufts' Friedman School who specializes in studying physical activity. "That is, the more you do, the more you benefit. Even a little bit of physical activity makes a significant difference for your health."
The greatest benefits, however, come from meeting or exceeding the guidelines for physical activity, such as walking about 10,000 steps or engaging in moderate exercise 30 minutes per day. "Even greater benefits are gained beyond that," Sacheck adds, "including of course increased fitness but also for brain health benefits, as seen in one of these new studies."
STEP IT UP: Evidence that taking it up a notch pays health dividends comes from a new study reporting that sedentary individuals who increased their steps from 1,000 to 3,000 a day reduced their mortality risk by 12%; those who achieved 10,000 daily steps cut their risk by 46%. Published in PLOS One, the study followed more than 2,500 Australians with an average age of about 59 for more than 10 years. Daily step activity was measured by pedometer.
"This shows more clearly than before that the total amount of activity also affects life expectancy," says researcher Terry Dwyer, MD, of the George Institute for Global Health in Sydney. "These results are more robust and give us greater confidence that we can prevent death from major diseases by being more active."
HEART SMARTS: In other recent research, a combined analysis of 12 large cohort studies, scientists found a linear relationship between increased physical activity and reduced heart-failure risk. Moderate physical activity such as walking the current minimum recommendation of 150 minutes a week was associated with a "modest" reduction in risk of heart failure. But doubling the activity time or boosting the exertion level, or a combination of exercising longer and harder, was associated with a 20% lower risk of heart failure. People who quadrupled the minimum recommended level saw a 35% lower risk.
Heart failure is a chronic condition in which the heart is unable to supply enough blood to meet the body’s demands. It affects more than 5.1 million US adults.
Jarett D. Berry, MD, of the University of Texas Southwestern Medical Center, and colleagues reviewed studies involving a total of more than 370,000 men and women. Participants self-reported their activity levels and were followed for an average of 15 years. The study was published in Circulation.
BRAIN EFFICIENCY: A third study adds to the ongoing investigation of the effects of physical activity on the brain. (See "Exercise and Your Brain: Should You Sweat It?" in the January newsletter.) Published in NeuroImage, the study linked aerobic fitness in older men to more efficient brain activity.
Researchers at the University of Tsukuba in Japan recruited 60 men, ages 64 to 75, who showed no signs of cognitive impairment. The men were tested for aerobic fitness, measured by oxygen intake during exercise. Then they were fitted with probes on their foreheads and scalps that used infrared light to show activity in various parts of the brain. While hooked up to the probes, participants were given a series of mental tests, such as being shown the word "red" in blue type and having to press keys matching the word rather than the type color.
In younger brains, such tests can typically be performed primarily in the left hemisphere. But these older men also needed their right brains to complete the tasks - except in the most fit participants. The brains of the fittest men performed more like those of younger people, and fit participants' keystrokes were faster and more accurate.
Although the study was not designed to prove cause and effect, researchers said the results suggest again that "higher aerobic fitness is associated with improved cognitive function."
TO LEARN MORE: PLOS One, Nov. 4, 2015—
TO LEARN MORE: Circulation, Nov. 10, 2015—
TO LEARN MORE: NeuroImage, Jan. 15, 2016 —