Reliability Of Vastus Lateralis Oxygenation Measured By Near Infrared Spectroscopy During Resistance Exercise
Bibliographic record
Abstract
Near infrared spectroscopy (NIRS) is a non-invasive optical technique that has been extensively used to monitor muscle oxygenation (Mox) during various tasks in different populations. However, its use during exercise has been restricted to aerobic or isometric activities, with very few attempts to investigate Mox during dynamic resistance exercise. PURPOSE To determine the reliability of vastus lateralis (VL) Mox measured by NIRS during isotonic knee extensions. METHODS Informed consent was obtained from 9 healthy volunteers (37.2 ± 10.2 yr; 74.1 ± 16.7 kg; 170.5 ± 9.6 cm) who randomly completed 4 sessions of 1 set of maximum repetitions (REPS) of the dominant leg on a knee extension machine with 80% 1RM at slow (SS: ∼25°·s−1) and fast (FS: ∼80°·s−1) speeds. A repetition was considered valid if range of motion was at least 60°. Test/ retest measurements were undertaken within a two-week period. The NIRS probe was positioned over VL (∼16 cm above knee joint) and Mox was continuously monitored during 2 min rest, REPS, and 3 min recovery. Variables considered for analysis after adjustment for baseline were: minimum during REPS plus recovery (MIN), range from MIN to maximum during recovery (RANGE), and time for half-recovery after REPS (T1/2). RESULTS Bland-Altman analysis revealed an outlier on FS REPS and one on SS Mox whose data were discarded. Mox data was further discarded for one subject in each speed due to probe displacement. Number of REPS were 6.1 ± 0.8 and 6.3 ± 0.9 for test and retest, respectively, for SS (n = 9; intraclass correlation coefficient, ICC = .674; p = .016); and 9.3 ± 1.9 and 9.9 ± 1.6, respectively, for FS (n = 8; ICC = .560; p = .046). For SS (n = 7), MIN (ICC = .730; p = .014), RANGE (ICC = .795; p = .006) and T1/2 (ICC = .780; p = .007) showed significant reliability, but only MIN (ICC = .854; p = .002) and RANGE (ICC = .973; p = .000) were reliable for FS (n = 7), with ICC = .309 for T1/2 (p = .773). CONCLUSIONS Reproducibility of Mox measurements of VL was moderately high at 80% 1RM during dynamic knee extensions to voluntary fatigue. NIRS is a suitable technique for evaluating Mox changes during resistance exercise. Partly supported by CAPES/Ministry of Education, FAPERJ (E-26/170.774/2003), and Righetto Fitness Equipment, Brazil.
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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 | 0.002 | 0.007 |
| 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 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".