Walking is a hobby I keep on for a long time. However, it is also a habit leading to being laughed at. I often walk about three miles from home to work instead of taking the subway. Sometimes, kind-hearted drivers will offer me a ride, thinking that my car has broken down.

But for me, walking is a good opportunity to relax myself. Besides, it helps my back recover from a day spent bent* in front of a computer screen. In terms of health, I have always thought I'd have the last laugh, and now there is even more evidence* on my side.

Scientists began a study on walking on volunteers in 2000. Nine years later, brain* scans showed that those who had walked more had greater brain volume* than those who had walked less. Four years after that, the volunteers were tested again--this time for dementia*. Among the group, 116 people showed signs of memory loss or dementia. Those who had walked the most--at least seven miles each week-- were half as likely to have cognitive problems as those who had walked the least.

Another study has found that the simple act of walking may improve memory in old age. As we become old, our brains shrink, which can lead to the loss* of memory. However, experts say there's still not enough data* to prove that exercise can stop memory loss. It's also too soon to say whether exercise may stop dementia or simply make it happen a little later in some people. But for those who suffer from dementia, even making it a little later could mean a lot.