Levels of Physical Activity during School Hours in Children and Adolescents: A Systematic Review
Bibliographic record
Abstract
Background: This systematic reviewdetermines the levels of physical activity (PA) during school\n\t\t\t\t hours in children and adolescents.Methods: Studies carried out fromJanuary 1987 toDecember 2019were\n\t\t\t\t retrieved from four databases (Web of Science, Pubmed, Scopus and SportDiscus). Results: Twenty-nine\n\t\t\t\t studies were included in this systematic review. Most of them used accelerometers and showed that male\n\t\t\t\t and female children accumulated a mean of between 14 and 68 min of moderate-to-vigorous PA (MVPA)\n\t\t\t\t during school hours (3–22% of this daily segment), andmale and female adolescents accumulated amean\n\t\t\t\t of between 13 and 28min ofMVPA during this daily segment (3–8% of the school hours). Less than a\n\t\t\t\t quarter of children and adolescents reached the recommended 30 min of MVPA during school hours,\n\t\t\t\t with notable differences between sexes. Conclusions: These results suggest that the levels of PA during\n\t\t\t\t school hours are not enough, and consequently, schools should develop strategies for helping children\n\t\t\t\t and adolescents reach the school PA recommendation.
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 | 0.007 | 0.033 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.007 | 0.007 |
| Bibliometrics | 0.010 | 0.011 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.002 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".