What is this article primarily about?

Question

The idea that teenagers enjoy tracking 10,000 steps a day as a fun activity
The idea that taking 10,000 steps daily has been popular but is not based on research
The marketing campaigns that were launched for the Tokyo Olympics in 1964
The use of Japanese characters in marketing gimmicks for fitness devices

Answer 1

The idea that taking 10,000 steps daily has been popular but is not based on research.