Dissociating The Effects Of Lung Size And Sex On The Work Of Breathing During Exercise
Bibliographic record
Abstract
BACKGROUND: During exercise, females have a higher work of breathing (WB) for a given minute ventilation (V̇E) >50-60 l·min-1 than males, presumably due to sex-differences in airway luminal area. However, on average, males have larger lung volumes than females, and the confounding effect of lung size on sex-differences in the WB has yet to be investigated. Purpose: To determine the independent effects of lung size and sex on the WB during exercise in healthy males and females. METHODS: n = 16 healthy adults (n = 10 males, n = 6 females) completed pulmonary function testing and an incremental cycle exercise test to exhaustion. Throughout the incremental exercise test, the WB was calculated based on measures of esophageal pressure and bidirectional flow obtained using an esophageal balloon catheter and open-circuit spirometry, respectively. A subset of n = 3 males and n = 3 females were matched for age (±5 y) and forced vital capacity (FVC; ±0.5 l). RESULTS: Across all participants, the WB was similar between the sexes at a V̇E of 35 ± 2 l·min-1 (p = 0.138), but significantly higher in females than in males at a V̇E of 68 ± 4 l·min-1 (p < 0.001). There was no significant effect of FVC on the WB at a V̇E of 35 ± 2 l·min-1 (p = 0.114) or 68 ± 4 l·min-1 (p = 0.798), regardless of sex. In a subset of males and females matched for age and FVC, sex-differences in WB during exercise remained evident, whereby females had a higher WB than males for a given V̇E > 55 l·min-1 (p < 0.05). CONCLUSION: Sex-differences in the WB during exercise persist after accounting for sex-differences in lung size. Our preliminary findings provide additional support for the notion that the higher WB during exercise in females relative to males is due to sex-differences in airway luminal area rather than lung size. Supported By: Natural Sciences and Engineering Research Council of Canada (RGPIN-2020-06564) and Research Manitoba (5409) operating grants
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 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) | 0.004 | 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".