Sweat your brain into shape

Exercise for the mind might sound like crossword puzzles and Sudoku -- but in reality, exercise benefits the rest of your body can also boost your brain.

And getting a little more blood-pumping exercise benefits now can actually pay huge dividends later in life: New research finds that fitness in middle age can slash the risk of dementia in your later years.

The study of close to 20,000 men and women -- many of whom were tracked for more than 40 years -- finds that people who get the most exercise by the age of 50 are 36 percent less likely to get dementia than those who get the least movement in middle age.

Exercise benefits your brain in a number of ways, starting with the immediate benefits like good circulation.

But the biggest benefits are more for the long term.

For example, people who get regular physical activity are less likely to be sedentary and obese, and less likely to get diabetes -- and all three of those things are big risk factors for dementia.

Exercise benefits can also lead to specific improvements within the brain itself.

Wish you had a bigger brain? Exercise can actually make it happen -- because while the human brain shrinks naturally with age, people who get regular physical activity have a slower rate of shrinkage, according to research I told you about a few months ago.

And a slower rate of shrinkage means a lower risk of dementia.

The brain-boosting benefits of physical fitness don't end there, either. People who get regular exercise benefits are less likely to have accumulations of beta-amyloid, aka the "brain plaques" that often appear in patients with dementia and Alzheimer's disease, according to other studies.

The researchers behind the new study in Annals of Internal Medicine say they hope to determine exactly how much exercise is needed to help prevent dementia, but there's no need to wait for those results to get started.

Just get moving, get your blood pumping and work up a sweat several times a week, and you'll help protect your brain and body alike.