A new study has found that engaging in a physical exercise regimen helps healthy aging adults improve their memory, brain health and physical fitness - a significant finding considering that, among adults 50 and older, "staying mentally sharp" outranks social security and physical health as their top concern.

For the study, sedentary adults ages 57-75 were randomized into a physical training or a wait-list control group. The physical training group participated in supervised aerobic exercise on a stationary bike or treadmill for one hour, three times a week for 12 weeks.

Participants' cognition, resting cerebral blood flow, and cardiovascular fitness were assessed at three time points: before beginning the physical exercise regimen, mid-way through at 6 weeks, and post-training at 12 weeks.

Results of CBF voxel based comparison superimposed on an average CBF map of all participants. Anterior cingulate cortex's CBF increased from T1 to T3 in the physical training group (shown in yellow) compared to the control group, p < 0.05 (FWE corrected) and k ≥ 664 mm³. 
doi: 10.3389/fnagi.2013.00075

"By measuring brain blood flow non-invasively using arterial spin labeling (ASL) MRI, we can now begin to detect brain changes much earlier than before," said Sina Aslan, Ph.D., founder and president of Advance MRI and collaborator on the study. "One key region where we saw increase in brain blood flow was the anterior cingulate, indicating higher neuronal activity and metabolic rate. The anterior cingulate has been linked to superior cognition in late life."

Exercisers who improved their memory performance also showed greater increase in brain blood flow to the hippocampus, the key brain region affected by Alzheimer's disease. Chapman pointed out that, using noninvasive brain imaging techniques, brain changes were identified earlier than memory improvements, implicating brain blood flow as a promising and sensitive metric of brain health gains across treatment regimens.

"Physical exercise may be one of the most beneficial and cost-effective therapies widely available to everyone to elevate memory performance," says Sandra Bond Chapman, Ph.D., founder and chief director of the The University of Texas at Dallas Center for BrainHealth and lead author of the paper. "These findings should motivate adults of all ages to start exercising aerobically."

Chapman cautioned that while physical exercise is associated with a selective or regional brain blood flow, it did not produce a change in global brain blood flow.

"In another recent study, we have shown that complex mental training increases whole brain blood flow as well as regional brain blood flow across key brain networks," Chapman said. "The combination of physical and mental exercise may be the best health measures to improve overall cognitive brain health. We have just begun to test the upper boundaries of how we can enhance our brain's performance into late life. To think we can alter and improve the basic structure of the mature brain through aerobic exercise and complex thinking should inspire us to challenge our thinking and get moving at any age."

Citation: Sandra B Chapman, Sina Aslan, Jeffrey S Spence, Laura F DeFina, Molly W Keebler, Nyaz Didehbani and Hanzhang Lu, 'Shorter term aerobic exercise improves brain, cognition, and cardiovascular fitness in aging', Frontiers In Aging Neuroscience 11/12/13 doi: 10.3389/fnagi.2013.00075