Summary: Lifting weights as little as once per week may improve your attention and thinking.
Several studies have shown that exercise might reduce your risk of memory loss, or even improve your memory and thinking. Most of these studies have focused on aerobic exercise such as walking or aerobics classes.
What about lifting weights? Research by Teresa Liu-Ambrose, Assistant Professor at the University of British Columbia, and her colleagues suggests lifting weights once or twice per week can improve attention and thinking in older women.
Lifting weights might not have an immediate effect. In this clinical trial, the women who lifted weights were split into two groups: those who trained once per week and those who trained twice per week. Both groups were compared to a group of women participating in a twice weekly balance and toning program. At the six month point, Dr. Liu-Ambrose and her colleagues found no significant differences between those lifting weights and those in the balance and toning program. At the one year point, however, the once per week group had improved performance by 12.6% and the twice per week group by 10.9%. The performance of the balance and toning group worsened slightly.
In a follow-up study one year after the formal training sessions ended, the once per week group still showed a 15% improvement on tests of attention and thinking over the balance and toning group.
Second, MRI brain scans showed the brains of the women in the weight-lifting groups shrank a bit, while the brains of those in the balance and toning group did not. Brain shrinkage is normally associated with a decline in memory and thinking. Similar shrinkage has been reported in groups receiving active treatments in some clinical trials, but scientists are unsure of what it means.
Third, women ages 65 to 75 were enrolled in this study, and it’s not clear that lifting weights would have the same effect for men or for women of other ages. Other studies have shown that exercise may affect men and women differently. “From my clinical perspective, compliance may be a key reason why women cognitively benefit more from exercise, says Dr. Liu-Ambrose, who is a registered physical therapist. “Also, we know from animal studies that socialization is beneficial for both cognitive and brain function. So it could be that the social aspect of group-based exercise classes has a more beneficial effect for women versus men. There is also evidence that estrogen may be a key factor.”
Finally, the women in the study did not have significant problems with memory and thinking. It’s not clear whether lifting weights would improve the attention and thinking of people who have more serious problems. Dr. Liu-Ambrose and her colleagues plan to study the effects of exercise on people with more progressive cognitive impairment or dementia.