Partitioning The Work Of Breathing During Running And Cycling Using Optoelectronic Plethysmography
Bibliographic record
Abstract
Work of breathing (B) derived from a single lung volume and pleural pressure is limited and does not fully characterize the mechanical work done by the respiratory musculature. It has long been known abdominal activation increases with increasing exercise intensity, yet the mechanical work done by these muscles is not reflected in B. Optoelectronic plethysmography (OEP) is a 3-dimentional motion analysis tool that measures the positions and displacements of reflective markers on the thorax and abdomen to calculate volume changes. Importantly, OEP permits an assessment of the ribcage and abdominal contribution to volume changes during breathing. PURPOSE: We sought to: (1) show the volumes measured using OEP (VCW) were comparable to volumes from flow integration (Vt) during cycling and running, and (2) to demonstrate that partitioned ribcage and abdominal volume from OEP could be utilized to quantify the mechanical work done by the ribcage (BRC) and abdomen (BAB) during exercise. METHODS: We fit 11 subjects (6 males/5 females; age, 26 ± 3 years; body mass, 73 ± 10 kg; height, 177 ± 6 cm; maximal oxygen uptake, 55.2 ± 9.8 ml/kg/min) with 89 reflective markers, and esophageal and gastric balloon catheters. Subjects completed an incremental cycling test to exhaustion and a series of submaximal treadmill running trials. RESULTS: We found good agreement between VCW vs. Vt during cycling (bias = 0.002) (p > 0.05) and running (bias = 0.016) (p > 0.05). From rest to maximal-exercise, BAB increased by 84% (range: 30-99%; BAB: 1 ± 1 J/min to 61 ± 52 J/min). The relative contribution of the abdomen increased from 17 ± 9% at rest to 26 ± 16% during maximal-exercise. CONCLUSION: Our study highlights and provides a quantitative measure of the role of the abdominal muscles during exercise. Incorporating the work done by the abdomen allows for a greater understanding of the mechanical tasks required by the respiratory muscles under physiologically relevant conditions such as exercise. Moreover, our approach could be used to gain insight into how the respiratory system functions under pathophysiological conditions and injury.
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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 | 0.001 |
| 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".