Maximum effort breath-hold times for males and females of similar pulmonary capacities during sudden face-only immersion at water temperatures from 0 to 33 °C
Bibliographic record
Abstract
For non breath-hold-trained males and females matched for pulmonary capacity and body size, the effects of sex, water temperature, and end-tidal gas tensions were studied for their potential influences on breath-holding ability. Maximum breath-hold time (BHTmax) was measured a total of 546 times in 13 males and 13 females, each repeating 3 trials of sudden face immersion (i.e., no prior hyperventilation) in water at 0, 5, 10, 15, 20, and 33 °C and in an air control condition (AIR). End-tidal carbon dioxide (PETCO2) and oxygen (PETO2) gas tensions were measured before and after breath-holding in a subset of 11 males and 11 females. For BHTmax there was no main effect of sex (p = 0.20), but there was a main effect of immersion condition (p < 0.001). Relative to pre-immersion rest values, end-tidal gas tensions were significantly higher in males than in females (p ≤ 0.05) and significantly lower at decreased water temperatures relative to AIR (p ≤ 0.05). In conclusion, for these matched groups (i) sex did not influence BHTmax; (ii) irrespective of sex, decreases in water temperature at 0, 5, 10, and 15 °C gave proportionate decreases of BHTmax; (iii) significantly greater deviations in both PETCO2 and PETO2 following breath-holding were evident in males relative to females; and (iv) irrespective of sex, there were significantly smaller changes in both PETCO2 and PETO2 at lower water temperatures relative to AIR, with or without removing the variance due to breath holding.
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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 | 0.000 | 0.000 |
| 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) | 0.003 | 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".