CORRECTS INFORMATION REGARDING THE STUDY'S RELEASE - FILE - In this May 26, 2009 file photo, Betty Hale, center, instructs a physical education class at Eberhart Elementary School in Ch

 

              CORRECTS INFORMATION REGARDING THE STUDY
CORRECTS INFORMATION REGARDING THE STUDY'S RELEASE - FILE - In this May 26, 2009 file photo, Betty Hale, center, instructs a physical education class at Eberhart Elementary School in Chicago. Conventional wisdom says school gym classes make a big difference in kids' weight. But a report in the Thursday, Jan. 31, 2013 issue of the New England Journal of Medicine says this is one of many myths that are detracting from real solutions to the nation's weight problems. According to the report, gym classes often are not long, often or intense enough to make much difference. (AP Photo/M. Spencer Green, File)