Dementia and Alzheimer’s disease are two of the most feared conditions facing American seniors. But, as a new study shows, something as simple as taking a walk may increase brain size and improve memory. 
Really? Walking? Yes, really.
See, as you age, a part of your brain called the hippocampus naturally shrinks. While this may not seem overly troubling at face value, when you consider that this seahorse-shaped lobe is responsible for long-term memory, you begin to see the problem.
Add on to this the fact that the hippocampus is one of the first parts of the brain to show signs of damage in Alzheimer’s patients, and it’s clear that maintaining the health of the hippocampus is a key strategy in warding off dementia and Alzheimer’s.
Fortunately, there may be an answer that doesn’t involve dangerous drugs. Over the years, researchers have noted that as the hippocampus deteriorates, memory loss increases.
Conversely, studies have shown that exercise is not only associated with improved memory , but with increased cell growth of the hippocampus . However, these studies were done with mice. Which begs the question, does exercise have the same effect on human brains?
Exercise Buffs Up Your Brain
In a new study published in the Proceedings of the National Academy of Sciences, researchers set out to evaluate whether exercise could increase the size of the hippocampus in older adults, while also improving memory.
In a randomized controlled trial with 120 adults aged 55 to 80 years old, researchers divided the group in two. The first group was asked to walk three days a week, while the second group performed stretching and toning exercises three days a week over the course of a year.
In the walking group, participants started off walking for 10 minutes a day during those three days at a speed slightly faster than their normal walking pace. They then increased their duration by five minutes each week, until the reached a maximum of 40 minutes by week seven. They then continued to walk for 40 minutes a day, three days a week.
For the stretching group, participants also worked out three days a week. They used a combination of dumbbells or resistance bands, yoga, balance exercises, and one exercise of their choice.
At the end of the year, researchers found that those participants who walked enjoyed a two percent increase in their hippocampus, as compared to a 1.4 percent increase in the stretching group. The walking group also enjoyed a 7.78 percent increase in maximal oxygen consumption (a marker associated with cardiovascular fitness), as compared with just a 1.11 percent increase in the stretching group.
Most important, however, while the increased hippocampal volume in the walking group was directly related to an improvement in memory performance, both groups showed improvements in memory, as well as an increase in response times.
This demonstrates that any exercise, particularly aerobic exercise, can increase the memory center of your brain while also improving memory. And that this improvement can be achieved in later years, meaning it’s never too late to start exercising.
As the study clearly shows, exercise doesn’t have to be intense or extreme to be effective. Simply walking 30 to 40 minutes most days of the week can boost your brain size and memory.
If walking is not an option for you due to injury or climate, try swimming, dancing, yoga, or even chair aerobics. The key is to get moving so you can keep those memories for years to come.
 Erickson, KI, et al. Exercise training increases size of hippocampus and improves memory. Proc Natl Acad Sci USA. 2011 Jan 31. [Epub ahead of print]
 Creer, DJ, et al. Running enhances spatial pattern separation in mice. Proc Natl Acad Sci USA. 2010. 07:2367-2372
 van Praag, H, et al. Exercise enhances learning and hippocampal neurogenesis in aged mice. J Neurosci. 2005. 25:8680-8685