Don’t just think about how your body will change if you decide to skip one workout or several weeks of training. Your brain will be negatively affected as well, according to a new study published in the journal Frontiers in Aging Neuroscience.
Stopping exercise decreases brain blood flow, including to the hippocampus, even if you were not being your usual physically active self for just 10 days. “We know that the hippocampus plays an important role in learning and memory and is one of the first brain regions to shrink in people with Alzheimer's disease,” says Dr. J. Carson Smith, associate professor of kinesiology and lead author of the study.
The hippocampus, a key brain area for memory, responds to working out by increasing the growth of new blood vessels and new neurons. In older people, exercise can help protect it from shrinking.
“We know that if you are less physically active, you are more likely to have cognitive problems and dementia as you age,” Dr. Smith says.
“The take home message is simple – if you do stop exercising for 10 days, just as you will quickly lose your cardiovascular fitness, you will also experience a decrease in blood brain flow.” Blood flow carries oxygen and needed nutrients to brain cells so the organ can function better.
The researchers observed 12 “master athletes.” They were 50+ years old adults who have long-term endurance training histories of at least 15 years. They were recruited from local running clubs.
Participants were asked to cease all training and vigorous physical activity for 10 consecutive days. Smokers or people who have smoked within the past 5 years were excluded. Volunteers with history of heart attack, stroke, lung or kidney disease, as well as anemia or diabetes were also ineligible. So were individuals taking prescription medication for hypertension.
Resting CBF (cerebral blood flow) significantly decreased in eight gray matter brain regions. Also, rCBF (resting cerebral blood flow) within the left and right hippocampus significantly decreased after 10 days of no exercise training.
Ending a workout program among physically fit individuals may provide a fresh method to evaluate the effects of acute exercise and exercise training on brain function in older adults.