Final answer:
Following World War II, American youth were found to be less fit than the youth of other nations.
Step-by-step explanation:
Following World War II, comparative studies showed that American youth were less fit than the youth of several other nations. These studies compared the physical fitness levels of American youth with that of youth from other countries, and generally found that American youth were less physically fit. This can be attributed to a variety of factors such as differences in access to educational resources and socioeconomic disparities.