Exercise builds bigger biceps and strengthens the heart. But of all the body parts that benefit from a good workout, the brain may be the big winner.
Physical fitness directly affects our mind and plays a crucial role in the way the brain develops and functions. Moreover, exercise is linked to brain changes throughout all stages of life, beginning in infancy and lasting through old age.
Babies, for example, need regular movement to carve out critical pathways and form connections in the brain. In children, research suggests exercise improves attention, focus and academic performance. And in the elderly, exercise has been shown to help stave off memory loss associated with some forms of dementia, including Alzheimer’s disease.
“Physical activity is crucial to mind and body alike,” said neuroscientist Lise Eliot. “The brain benefits as much as the heart and other muscles from physical activity.”
Exercise, it turns out, can help improve cognition in ways that differ from mental brain-training games.
How does exercise help the brain?
In the mid-1990s, Carl Cotman’s team at the University of California-Irvine first showed that exercise triggers the production of a protein called brain-derived neurotrophic factor, or BDNF, which helps support the growth of existing brain cells and the development of new ones.
With age, BDNF levels fall; this decline is one reason brain function deteriorates in the elderly, according to Cotman. Certain types of exercise, namely aerobic, are thought to counteract these age-related drops in BDNF and can restore young levels of BDNF in the aging brain.
“In a sense, BDNF is like a brain fertilizer,” said Cotman. “BDNF protects neurons from injury and facilitates learning and synaptic plasticity.”
Here’s a look at how physical activity can be beneficial during three key stages of life.
Infancy: Mobile children hit their cognitive milestones faster, said Eliot, an associate professor of neuroscience at Rosalind Franklin University’s Chicago Medical School.
When infants are awake, they’re in near-constant motion, which is critical for development, Eliot said. This movement “strengthens their muscles and hones their neural circuits for smooth, purposeful motor skills.”
She worries that babies in the U.S. are spending too much time strapped in devices.
Pre-adolescence: In a new twist in the debate over physical education in schools, researchers are asking an intriguing question: What if exercise improves academic success?
Some research suggests it can. Researchers at the University of Illinois found that children ages 7-9 who participated in a 60-minute after-school exercise program had better focus, processed information more quickly and performed better on cognitive tests than children who didn’t exercise.
The researchers also found that the more days the children attended the exercise program, the greater the changes in their brain function.
Late adulthood: The hippocampus, a structure near the center of the brain, naturally shrinks in late adulthood, leading to impaired memory and increased risk for dementia. But research suggests aerobic exercise can increase the size of the hippocampus and increase levels of a protein that aids the growth of new brain cells, potentially holding off changes in the brain and improving memory function.