▁for ▁m ild ▁cogn itive ▁imp air ment ▁states ▁that ▁clin icians ▁should ▁recommend ▁regular ▁exercise ▁( two ▁times ▁per ▁week ) ▁to ▁individuals ▁who ▁have ▁been ▁diagn osed ▁with ▁this ▁condition . ▁This ▁guidance ▁is ▁based ▁upon ▁a ▁moder ate ▁amount ▁of ▁high - quality ▁evidence ▁which ▁supports ▁the ▁effic acy ▁of ▁regular ▁physical ▁exercise ▁( tw ice ▁week ly ▁over ▁a ▁ 6 - month ▁period ) ▁for ▁impro ving ▁cogn itive ▁sympt oms ▁in ▁individuals ▁with ▁m ild ▁cogn itive ▁imp air ment . ▁ ▁Ne uro de gener ative ▁dis orders ▁ ▁Al z heimer ' s ▁disease ▁ ▁Al z heimer ' s ▁D ise ase ▁is ▁a ▁cort ical ▁ne uro de gener ative ▁dis order ▁and ▁the ▁most ▁pre val ent ▁form ▁of ▁de ment ia , ▁representing ▁approximately ▁ 6 5 % ▁of ▁all ▁cases ▁of ▁de ment ia ; ▁it ▁is ▁character ized ▁by ▁imp a ired ▁cogn itive ▁function , ▁behavior al ▁ab normal ities , ▁and ▁a ▁reduced ▁capacity ▁to ▁perform ▁basic ▁activities ▁of ▁daily ▁life . ▁Two ▁meta - anal yt ic ▁system atic ▁reviews ▁of ▁random ized ▁controlled ▁tri als ▁with ▁dur ations ▁of ▁ 3 – 1 2   month s ▁have ▁exam ined ▁the ▁effects ▁of ▁physical ▁exercise ▁on ▁the ▁a for ement ioned ▁characteristics ▁of ▁Al z heimer ' s ▁disease . ▁The ▁reviews ▁found ▁benef icial ▁effects ▁of ▁physical ▁exercise ▁on ▁cogn itive ▁function , ▁the ▁rate ▁of ▁cogn itive ▁decl ine , ▁and ▁the ▁ability