Inter‐individual differences in coupling oxygen delivery to demand during a progressive exercise test
Bibliographic record
Abstract
Oxygen delivery (O 2 del) to exercising muscle is thought to be tightly coupled to metabolic demand, as evidenced by proportional increases in O 2 del with increasing exercise intensity. Little consideration has been given to investigation of inter‐individual differences in this coupling. PURPOSE To characterize inter‐individual differences in O 2 del:metabolism coupling during progressive increases in exercise intensity. METHODS 8 healthy males (24.4 ±6.4 yrs) performed rhythmic isometric handgrip contractions (1 s:2 s contraction:relaxation duty cycle, contraction force increased by 2.5 kg every 3 min. 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). RESULTS Data are mean ±SD. From rest to end of the 17.5 kg stage the 1) total blood delivered to the forearm was 3565.282 ±1013.584 mL, coefficient of variation (CV) 28%, range 2321.132 to 5384.500 mL and 2) total O 2 delivered to the forearm was 533.306 ±153.192 mL, CV 29%, range 312.520 to 786.140 mL. Mean blood flow at 17.5 kg was 345.510 ±89.782 mL. CONCLUSIONS Inter‐individual differences in blood flow and O 2 del:metabolism coupling during small muscle mass ramp exercise protocol can be substantial. Implications for understanding O 2 del:metabolism coupling need to be considered.
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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".