Quadriceps Muscles O2 Extraction and EMG Breakpoints during a Ramp Incremental Test
Bibliographic record
Abstract
Muscle deoxygenated breakpoint ([HHb]BP) has been found to be associated with other indices of exercise tolerance in the vastus lateralis (VL) muscle but not in the vastus medialis (VM) and rectus femoris (RF). Purpose: to investigate whether the [HHb]BP occurs also in the VM and RF muscles and whether or not it is associated with other physiological indices of exercise tolerance, such as the EMG threshold (EMGt) and the respiratory compensation point (RCP). Methods: 12 young endurance trained participants performed maximal ramp incremental tests (25-30 W·min-1 increments). Muscle oxygen extraction and activity as well as gas exchange parameters were measured. After accounting for the mean response time, the oxygen uptake (V̇O2) associated to the RCP, [HHb]BP, and the EMGt was determined. Results: peak power output (POpeak) was 359±48 W. Maximal V̇O2 (V̇O2max) was 3.87±0.46 L·min-1. The V̇O2 at the RCP was 3.39±0.41 L·min-1. The V̇O2 (L·min-1) corresponding to the [HHb]BP and EMGt were: 3.49±0.46 and 3.40±0.44; 3.44±0.61 and 3.43±0.49; 3.59±0.52 and 3.48±0.46 for VL, VM, and RF, respectively. Pearson’s correlation between these thresholds ranged from 0.90 to 0.97 (P 0.05). Although in eight out of twelve participants, the [HHb]BP in the RF led to a steeper increase instead of leading to a plateau-like response as observed in the VL and VM, the V̇O2 at the breakpoints still coincided with that at the RCP. Conclusions: this study demonstrated that local indices of exercise tolerance derived from different portions of the quadriceps are not different to the systemic index of the RCP.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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) | 0.000 | 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 teacher head, 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".