共用题干

共用题干
第三篇

Smart Exercise

Doctors are starting to find more and more information that suggests a connection
between exercise and brain development.Judy Cameron,a scientist at Oregon Health and
Science University,studies brain development.According to her research,it seems that
exercise can make blood vessels,including those in the brain,stronger and more fully
developed.Dr. Cameron claims this allows people who exercise to concentrate better. As
she says:"While we already know that exercise is good for the heart,exercise can literally
cause physical changes in the brain."
The effects of exercise on brain development can even be seen in babies.Babies who
do activities that require a lot of movement and physical activity show greater brain
development than babies who are less physically active.With babies,even a{ittle
movement can show big results. Margaret Barnes , a pediatrician（儿科医师）,believes in
the importance of exercise.She thinks that many learning disabilities that children have in
elementary school or high school can be traced back to a lack of movement as babies.
"Babies need movement that stimulates their five senses.They need to establish a
connection between motion and memory.In this way,as they get older,children will begin
to associate physical activity with higher learning,"says Margaret.
Older people can beef up their brains as well.Cornell University studied a group of
seniors ranging in age from seventy to seventy-nine. Their study showed a short-term
memory increase of up to 40 percent after exercising just three hours a week.The exercise
does not have to be very difficult,but it does have to increase the heart rate.Also,just like
the motion for infants,exercise for older people should involve some complexity.Learning
some new skills or motions helps to open up memory paths in the brain that may not have
been used for a long time.
For most people,any type of physical activity that increases the heart rate is helpful.
The main goal is to increase the brain's flow of blood.And your brain can benefit from as
little as two to three hours of exercise a week.

To be beneficial,exercise for older people should
A:be done in a group.
B: be done on a daily basis.
C: involve great difficulty.
D:increase the heart rate.