Aerobics Or Toning? Which One Can Grow Back Your Memory?

The human hippocampus: image via nmr.mgh.harvard.eduThe human hippocampus: image via nmr.mgh.harvard.eduThe hyppocampus is the brain structure responsible for all memory formation.  When it shrinks during aging, it is also responsible for memory loss.  In the first project of its kind, researchers at the University of Pittsburgh, University of Illinois, Rice University, and Ohio State University, studied the brains of older persons who were already experiencing atrophy of the hippocampus to see if and what kind of exercise might increase the size of the hippocampus.

Physically fit adults, including older people, generally have larger hippocampal and medial temporal lobe volumes than others their age who are not fit.  And it is known that consistent exercise helps make the hippocampus larger.  What was not known is whether any change in physical activity in late adulthood could help those who are sedentary. 

The researchers tested 120 older adults, 60 of whom were on an aerobic exercise regimen (40 minutes a day, 3 times per week) and 60 that did toning and stretching exercises for the same time periods.

Magnetic resonance imaging (MRI) and memory tests were taken at the start of the experiments as well as after 6 months and one year.  MRI's showed that those in the aerobics group had an increase in the right hippocampus of 2.12 percent and of the left, 1.97 percent.  In the stretching/toning group, participants experienced a decrease in volume of 1.4 and 1.43 percent respectively.  Additionally, the molecule BDNF (brain-derived neurotrophic factor) that is involved in learning and memory was associated with the growth of the hippocampus among the aerobic exercisers.  Memory tests likewise improved for those in the aerobic group when compared to their original results. 

"We think of the atrophy of the hippocampus in later life as almost inevitable," said Kirk Erickson, professor of psychology at the University of Pittsburgh and the paper's lead author. "But we've shown that even moderate exercise for one year can increase the size of that structure. The brain at that stage remains modifiable."

Toning and stretching may not bring back your memory, but they sure contribute to the health of your muscles and joints.  Don't stop doing them in favor of aerobics.  They're all good for you.

Sources:, PNAS,