His group’s study did not examine, though, how those men and women who raised their fitness managed that feat. Which makes the other new study about exercise and memory a valuable complement.
In that experiment, which was published recently in Applied Physiology, Nutrition, and Metabolism, researchers at McMaster University in Ontario, Canada, tested what types of exercise might be most effective at increasing both aerobic fitness and memory performance in healthy, older adults.
They began by recruiting 64 sedentary men and women aged 60 or older and measuring their fitness and thinking skills. The researchers focused, in particular, on the participants’ ability to differentiate similar memories, such as where in the same parking lot someone left his or her car yesterday versus today. This kind of recall often declines with age, and a poor performance can mark the start of mild cognitive impairment and, in some cases, dementia.
After testing, the researchers randomly assigned the volunteers to visit the lab and stretch, as a control group, or start exercising. One of the exercise groups walked moderately and steadily on treadmills three times a week for about 50 minutes. The others began interval walking, during which their treadmills’ incline was cranked high for four minutes so that their heart rates rose to about 90 percent of each person’s maximum, followed by three minutes of easy walking, and three more rounds of the incline intervals.
After 12 weeks, the volunteers repeated their fitness and cognitive tests, with striking results. Only the interval walkers now showed significant improvements in both physical endurance and memory performance, and their gains were linked. The more fit someone became, the more his or her memory sharpened.
In essence, the findings suggest that “it is not too late” for middle-aged or older people to start exercising and protect their memories, says Jennifer Heisz, an associate professor at McMaster University who oversaw the new study.
But the exercise probably needs to be at least somewhat intense, so that it raises heart rates and gooses fitness. “I tell people to add in some hills when they go for a walk,” she says, “or pick up the pace between street lamps.”
Dr. Wisloff would agree. For endurance and brain health, he says, try regularly to “exercise with an intensity so that you get out of breath.”