4.Run,swim,lift weights,do yoga-do something,because it's good for you.Many studies tell us that regular exercise not only helps our bodies but improves memory,and eases anxiety.But what is happening to the mind during workout to create all these benefits?
A new study from Sweden suggests that a specific protein found in trained muscles might contribute to exercise's mental benefits.This protein,the researchers found,might help our bodies process molecules that,if out of balance,can stress us and contribute to depression(萎靡不振).The findings were published in the journal Cell.
To test this,the researchers kept attacking some mice with flashing lights,loud noises and interrupting their sleep for weeks.Predictably,this treatment makes the mice show signs and biochemical markers of depression.
But not all the mice showed those signs.One group,specially raised to have high levels of a protein called PGC-1alpha1 (the one in trained muscles),did not show those depression signs.PGC-1alpha1 increases production of an enzyme that breaks down a chemical called kynurenine.Kynurenine helps the body respond to an activated immune system(活性免疫系統(tǒng)),but it also plays a role in depression.
"Our original research assumption was that trained muscle would produce a substance(物質) with beneficial effects on the brain,"Jorge Ruas of the Karolinska Institute told Forbes.com."We actually found the opposite:well-trained muscle produces an enzyme that removes harmful substances away from the body."
This study was in mice,but it lines up nicely with all the other lines of evidence that exercise is good for mental health.
32.According to the study,which of the following is bad for your mental healthD?
A.Protein.
B.Molecule.
C.Enzyme.
D.Kynurenine
33.What conclusion have the researchers drawn from the studyD?
A.Unbalanced exercise leads you to depression.
B.Well-fed mice survive better though being ill-treated.
C.Trained muscle produces a substance good for brain.
D.Regular exercise helps to clear rubbish away from body.
34.According to the last paragraph,the result of the study isA.
A.reliable
B.doubtful
C.predictable
D.a(chǎn)mbiguous
35.What's the main idea of the passageC?
A.Why do you need regular exercise?
B.What matters most for your body?
C.How does exercise help your brain?
D.Why are mice chosen for the study?