ThepreviousSpecialIssuewasdevotedtophysicalactivity(PA),physicalfitness,diet,andhealthinyoungpeople.ThecontentofthissecondSpecialIssuewillfocusonPAandchronicdiseaseinchildrenandyoungadults.ThefirstpaperwrittenbyDurstineetal.considerstheproblemofchronicdiseasesbecomingapublichealthconcernworldwidewithestimatesoftrillionsofdollaisinannualhealthcarecostsandcausingmorethan36milliondeathsayear.Their