Inter‐individual differences in coupling oxygen delivery to exercising muscle metabolic demand
Bibliographic record
Abstract
That oxygen delivery (O 2 del) is “tightly matched” to metabolic demand is widely accepted based on traditional data analysis using group means. Little consideration has been given to the investigation of inter‐individual differences in this coupling. PURPOSE To determine the degree of inter‐individual differences in O 2 del:metabolic demand coupling in healthy young males. METHODS Eleven recreationally active (271.38 ± 6.74 METS) healthy males (24.18 ± 2.08 yrs) performed rhythmic isometric handgrip contractions at a fixed metabolic demand (1 s: 2 s contraction: relaxation duty cycle, 30 kg force) until failure. Forearm O 2 del was calculated as arterial oxygen content (O 2 saturation via pulse oximeter; [hemoglobin] via venous blood sample) x brachial artery blood flow (BABF; Doppler and Echo ultrasound). Data are mean ±SD. RESULTS BABF in last 30 s of exercise: 478 ±150 ml/min, Coefficient of variation (CV) 31%, individual subject values 249, 589, 465, 317, 475, 412, 391, 420, 700, 739, 499 ml/min. O 2 del last 30 s of exercise: 98 ±30 ml/min, CV 31%, individual subject values 55, 117, 92, 69, 88, 85, 75, 88, 141, 152, 115 ml/min. CONCLUSIONS “Tightness” of O 2 del:metabolic demand coupling varies substantially between individuals. Investigating inter‐individual variation may provide an important new approach to advancing understanding of integrated cardiovascular response support of exercising muscle. NSERC
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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) | 0.001 | 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".