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does exercise have unexpected benefits
just as exercise strengthens the heart and lungs,bones and muscles,it may also power up the brain .a succession of scientific studies of animals implies that physical activity has a positive effect on mental functioning .
"it's clear that the brain benfits from exercise,"says brain scientist willian greenough of the university of illinois at urbana-champain.his studies with rats have demonstrated two primary effects of activity:vigorous physical exercise provides the brain with more fuel,and skill-based exercise increasesthe formation of connection in the brain ,which according to the proposals of some scientists,may make the brain better able to process information.
in one experiment,laboratory rats were separated into three groups.one group was exercised by running inside an automatic wheel,a second group improved their skills in a complicatied obstacle course ,and a third group was inactive.
the animal was learned to go through the obstacle course exhibited a greater number of brain connection than the animals in the exercise or inactive group,greenough said ,in contrast ,the animals that exercised inside the automatic wheel possessed a greater density of blood vessels in the brain than did either of the other two group of animal.
learning a new dance step may boost the brain in the same way that learning a language can,he says.and if the dance is a good physical exercise as well,the benfits multiply .young brains may be especially able to boost brain power through exercise,suggested another of greenounh's experiments that showes the most significant changes in the brain occured among rats that had been exercised when very young.and while animals aren't people,he said it is logical to make the inference that an effect found in rats may also apply to humans.
humans studies have foused primaily on older adules and suggest that regular exercise can improve the speed with which the brain processes information.measurements made by arthur kramer at the universityof illionis demonstrated that inactive adults,age 63to82,could hit buttons faster in respondse to a tone after they went through a10-week water exercise course.a corresponding control group that didn't exercise showed no improvement.
this boost in reaction time after exercise training may occur because declines associated with getting old could actually stem from declines in physical condition.some scientists speculate the redution in mental funtion often attributed to getting old may really be a penalty of neglecting to stay physically active ,in addition to related factors such as medicines and poor diet.
in older people,an exercise program appears impsrtant for brain maintenance,says daniel m,landers ,professor of exercise science at arizona state university,who recently published an article reviewing the scientific literture on activity's effect on the brain.
numerous studies show that children who engage in regular physical activity do better in school than their inactive classmates.but until recently ,the academic edge gained by participating in sports was thought to come from the increased self-confidence,the better mood ,and the ability to concentrate that comes from buring off steam in exercise.now ,however,some scientists have revised their way of thinking,and point to possible physical connections.
pierce j,howard ,another expert ,says new research indicates that physical exercise increases the amount of certain brain chemicals that stimulate growth of nerve cells.conseqrently,the brain of people who exercise may be better equipped to tackle mental challenges.
inactivity may also have negative effects on mind and body alike ,..." scientists recognize that mind is body,and body is mind ," comments howard.the most beneficial forms of exercise ,he says ,engage both

Whether excercise does have unexpected benefits has been a chronic and heated debate between scholars and ordinary people. While i concede that exessive exericse is counterproductive and even detrimen...