Physical Activity, Screen Time, and Sitting Among U.S. Adolescents
Bibliographic record
Abstract
The purpose of this study was to describe self-reported levels of sitting, moderate- to vigorous-intensity physical activity (MVPA), television viewing, and computer use in a representative sample of US adolescents and to make comparisons between sex, race/ethnicity, weight status, and age groups. Results are based on 3556 adolescents aged 12-19 years from the 2007-2012 National Health and Nutrition Examination Survey. Participants self-reported demographic, sitting, MVPA, television viewing (2011-2012 only) and computer use (2011-2012 only) variables. Height and weight were measured to calculate body mass index. On average, 7.5 hr/day were spent sitting and 34 median min/day were spent participating in MVPA, with females sitting more and participating in less MVPA than males across most demographic groups. Furthermore, obese males sat more and participated in less MVPA than nonoverweight males. Non-Hispanic white females participated in more MVPA than females in all other race/ethnicity groups. For television and computer, 38% and 22% of the sample engaged in >2 hr/day, respectively, and several race/ethnicity differences were observed. This study provides the first U.S. adolescent population estimates on self-reported sitting and updates population estimates on self-reported MVPA, television viewing and computer use. Continued efforts are needed to promote healthy active lifestyles in American adolescents.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".