Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
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A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Various divisions of the respondents in the study.
| Group | Description | Group |
|---|---|---|
| 1 | No sports games or taekwondo activities | Negative control |
| 2 | Only sports games | Test |
| 3 | Only taekwondo | Test |
| 4 | Both sports games and taekwondo activities | Test and positive control |
