Everyone in both groups worked out three times a week at first, for about half an hour and under supervision. They then added sessions on their own, until after six months, they were completing about five workouts most weeks. This program continued for a year, in total. About 20 volunteers dropped out over that time, mostly from the walking group.
Then the volunteers returned to the lab for a repeat of the original tests, and the researchers compared results. To no one’s surprise, the exercise group was more fit, with higher aerobic capacity, while the stretchers’ endurance had not budged. The aerobic exercise group also showed much less stiffness in their carotid arteries and, in consequence, greater blood flow to and throughout their brains.
Perhaps most important, they also performed better now than the stretch-and-tone group on some of the tests of executive function, which are thinking skills involved in planning and decision-making. These tend to be among the abilities that decline earliest in dementia.
Interestingly, though, both groups had raised their scores slightly on most tests of memory and thinking, and to about the same extent. In effect, getting up and moving in any way — and perhaps also interacting socially with people at the lab — appeared to have burnished thinking skills and helped to stave off accelerating declines.
Still, the researchers believe that over a longer period of time, brisk walking would result in greater cognitive gains and less memory decline than gentle stretching, says Rong Zhang, a neurology professor at UT Southwestern Medical Center, who oversaw the new study.
“It probably takes more time” than a year for the improved brain blood flow to translate into improved cognition, he says. He and other researchers are planning larger, longer-lasting studies to test that idea, he says. They hope, too, to investigate how more — or fewer — sessions of exercise each week might aid the brain, and whether there might be ways to motivate more of the volunteers to stick with an exercise program.
For now, though, he believes the group’s findings serve as a useful reminder that moving changes minds. “Park farther away” when you shop or commute, he says. “Take the stairs,” and try to get your heart rate up when you exercise. Doing so, he says, may help to protect your lifelong ability to remember and think.