A stronger heart may help keep your brain young

by Harvard Health:

Exercise that speeds up your heart rate and breathing keeps your heart and blood better cardiovascular fitness to a sharper brain is providing new clues about this heart-mind connection.

“It’s not just about delivering more oxygen to the brain, although that’s part of it,” says Dr. John Ratey, associate clinical professor of psychiatry at Harvard Medical School and author of Spark: The Revolutionary New Science of Exercise and the Brain. Having a fit, healthy cardiovascular system also protects against vascular dementia, which happens when blood vessels feeding the brain are blocked or narrowed, leading to memory problems and other cognitive trouble.

In addition, exercise stimulates the growth of new blood vessels in the brain, as well as the growth and survival of new brain cells, says Dr. Ratey. Brain imaging studies suggest that key brain areas responsible for thinking and memory are larger in people who exercise than in those who don’t.

Measuring cardio fitness

One of the challenges in exercise research is the variability in how different researchers (and study participants) define and quantify moderate and vigorous exercise. To get around that issue, some recent studies use a standard measure of cardiovascular fitness, known as VO2 max, which assesses how well your heart, lungs, and muscles function during intense exercise (see “What is VO2 max?”). These values are then compared with findings from cognitive tests and brain scans.

One study, in the Feb. 2, 2016, Neurology, relied on data from nearly 900 adults with an average age of 65. Higher cardiorespiratory fitness levels were associated with better overall thinking ability, as well as better performance on tests of memory, motor skills, and executive function (mental skills used to manage time, plan and organize, and remember details). When researchers divided the participants into four groups based on their VO2 max values, they found striking differences in executive function between those with the highest and lowest levels. In fact, the test score differences corresponded to an age difference of seven years, they estimated. They saw similar trends for both memory and overall thinking ability, corresponding to age differences of six and four years, respectively.

Better brain connectivity

For another report, published in the journal Neuroimage last year, participants underwent functional MRI testing, which tracks changes that take place when a region of the brain responds during various tasks. Researchers found stronger connections between different regions of the brain in people with higher levels of cardiorespiratory fitness. Earlier research correlated fitness levels with activation in the brain’s frontal lobe—the part of the brain responsible for executive function.

Together, these findings suggest that exercise may help keep your brain young, or at least slow down the normal decline in age-related thinking skills. The government’s Physical Activity Guidelines for Americans are more than adequate for that purpose, says Dr. Ratey. For all adults, the weekly goals are two hours and 30 minutes of moderate-intensity aerobic activity like brisk walking OR one hour and 15 minutes of vigorous-intensity activity, like jogging muscle-strengthening activities on two or more days.

If you’re 65 or older and have a chronic health problem, just be as active as your abilities allow. “I know of a lot of older people who use walkers who still get in 10,000 steps a day. It just takes them a while,” says Dr. Ratey.

What is VO2 max? VO2 max is defined as the maximum amount of oxygen your body can use while you’re exercising as hard as you can. V stands for volume, which is usually measured in milliliters of oxygen per kilogram of body weight per minute. O2 is for oxygen, and max is for maximum. The test requires breathing into an oxygen mask while walking on a treadmill at a certain pace for a set amount of time. But unless you’re a runner or cyclist training to break a record, you probably don’t need to know your VO2 max. The better physical shape you’re in, the higher your VO2 max. Most adults are in the 25-to-40 range, and endurance athletes are often between 60 and 70.Source: http://bit.ly/22lKfCNImage: Thinkstock