A few months ago, I wrote a
blog post in response to a “pre-arranged”
submission by Kirk Erickson and colleagues to
Proceedings of the National Academy of Sciences (PNAS), which purported to find evidence that moderate exercise leads to substantial improvements in memory. The article in question received a
great deal of
media attention, with big claims being made that older adults, who tend to be worried about declining memory abilities, might be able to hold off the effects of old age on memory with a simple exercise regime.
Unfortunately, when the data were looked at more closely, it was clear that the picture was more complicated. For one thing, although the experimental group that performed exercise for one year did show a 2.3% increase in memory score, a control group who did not perform the exercise showed a 3.7% increase over the same period. In other words, the exercise group did not show any increase in memory performance relative to the control group.