Clinical Impact of Time of Day on Acute Exercise Response in COPD
Bibliographic record
Abstract
The purpose of this pilot study was to determine the impact of time of day on the acute response to incremental exercise in chronic obstructive pulmonary disease (COPD). Fourteen subjects (nine men) aged 71 ± 7 years with moderate to severe airflow obstruction (FEV1: 58 ± 13% predicted) followed a counterbalanced randomized design, performing three symptom-limited incremental cycling tests at 8:00, 12:00, and 16:00 hours on different days, each preceded by a spirometry. COPD medications were withdrawn prior to testing. No overall time effect was found for peak exercise capacity (p = 0.22) or pulmonary function (FEV1, p = 0.56; FVC, p = 0.79). However, a large effect size (f = 0.48) was observed for peak exercise capacity and several pulmonary function parameters. For peak exercise capacity, the average within-subject coefficient of variation was 5.5 ± 3.9% and the average amplitude of change was 7 ± 5W. Seven subjects (50%) showed diurnal changes at levels equal to or beyond the minimal clinically important difference for both peak exercise capacity and pulmonary function. In this sub-group, peak exercise capacity was greatest at 16:00 hours (p = 0.03, ƒ = 1.04). No systematic time-of-day effect on peak exercise capacity was obtained in COPD patients in the present pilot study. However, based on the observed effect size and on the average amplitude of change and within-subject variations seen across testing times, the guidelines recommendation that time of day be standardized for repeat exercise testing in COPD should be maintained.
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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 | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| 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) | 0.002 | 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".