中国大学MOOC:Task:ReadthearticleaboutakindoffitnesstrainingcalledHIIT.Thenchoosethebestexplanationsforsomeofthewordsandexpressions.HIIT:Isthefitnessscenesbiggestfaddoingmoreharmthangood?1.HighIntensityIntervalTraining(HIIT)hasbeenthedarlingofthefitnesssceneforafewyearsnow.Fundamentally,itinvolvesrepetitionsofshortburstsofintense,maximaleffortexercise;usuallyforanywherebetween20to40seconds.2.ThetheorybehindHIITisveryappealing.Byworkingoutatyourtoplevelofexertion,youburnmorecaloriesinashortspaceoftimethanotherworkouts.Whatsmore,studiesshowthatyourmetabolismstaysinaheightenedstateforupto24hoursafteryouvefinished.Andinpractice,HIITcanhaveimpressiveresults.Itsaneffectivetoolforincreasingcardiovascularfitness,sculptingyourphysiqueandincreasingmetabolicrate.HencewhyHIITclassesarepoppingupallovertheplace.Peoplehavebecomeaccustomedtoturninguptoaclasswithloudmusicanddarklighting,justlikeanightclub–andleavinginthesamestate:barelyabletowalk.3.However...IhaveabigbonetopickwithHIIT,whichisthattheresoftennofocusonformortechniqueintheseclasses,eventhoughitsnowprescribedasthego-toformofexerciseforeveryone.Instead,themeasureofagoodHIITsessionsseemstobehowdestroyedyoufeelafteraclass.Itsinevitablethatproblemsarisefromthisallpainforgainapproach.4.Oneissueissimplythatpeoplearedoingworkoutsthattheyrenotconditionedfor.Thereisnoemphasisonflexibility,mobilityoractivationinmanyHIITclasses;yetallareincrediblyimportantinkeepingthebodyfitandhealthyasyouage.5.Whatsmore,Iregularlyseepeople“smashing”multipleHIITclassesaday,5-6daysperweek.HIITshouldnotbedonemorethanthreetimesperweek(atmost),becauseitissostrenuous.Itputsanincrediblestrainonyournervoussystem,jointsandmuscles;especiallyifyouareoverweightandunfit.6.TheHIITapproachtoexercisehasgoneOTT.Itsenteringunsustainableterritory.7.HIIT’sriseinpopularityissymptomaticofwhatiswrongwiththefitnessindustryasawhole:abrazendisregardofthefundamentals,andadetrimental“onesizefitsall”mentality.Havingtrained100sofclientsinmyfiveyearsasapersonaltrainer,thebiggestissuesmostpeoplehavearealackofflexibility,mobilityandcorestrength,ontopofmuscleactivationissues.AlloftheabovecanleadtochronicinjuriesandarefurtherexacerbatedbyHIIT.8.Mybeliefisthateveryoneshouldtrytotrainlikeathletesdo.Idon’tmeanthesametrainingfrequencyandintensityasathletes,Imeanthementalityandtheapproach.Havingtrainedasacompetitivesprinterforfouryears,Ilearnedtotakeeveryaspectofmylifeintoaccount:sleep,restdays,nutritionandweaknesses.Ilearnttolistentomybody.SomedaysIwouldwakeupfeelingtiredandfatigued,soonthosedaysIwouldn’ttrainhard.Iwoulddosomethinglessintenseandfocusonrecovery.9.Remember:burningcaloriesisntthebeallandendalloffitnessandgoodhealth.Yes,HIITmayburnmorecaloriesthananyotherformofexercise,butitsnouseifitleadstoinjuryorillness.Overtrainingisarealdanger:itcanruinyourimmunesystem,causeinsomnia,affectyourappetiteandreleasecortisol,whichinturncanmakeyoumorelikelytoputonfat.********************************************Whatdoestheword“fad”inthetitleprobablymean?