Thefitnessmovementthatbeganinthelate1960sandearly1970scenteredaroundaerobicexercise(有氧操).Millionsofindividualsbecameengagedinavarietyofaerobicactivities,andliterallythousandsofhealthspasdevelopedaroundthecountrytocapitalize(获利)onthisemerginginterestinfitness,particularlyaerobicdancingforfemales.Anumberoffitnessspasexistedpriortothisaerobicfitnessmovement,evenanationalchainwithspasinmostmajorcities.However,theirfocuswasnotonaerobics,butratheronweight-trainingprogramsdesignedtodevelopmuscularmass,strength,andenduranceintheirprimarilymaleenthusiasts.Thesefitnessspasdidnotseemtobenefitfinanciallyformtheaerobicfitnessmovementtobetterhealth,sincemedicalopinionsuggestedthatweight-trainingprogramsofferedfew,ifany,healthbenefits.Inrecentyears,however,weighttraininghasagainbecomeincreasinglypopularformalesandforfemales.Manycurrentprogramsfocus