Effects Of Inspiratory Muscle Training On Inspiratory And Locomotor Muscle Hemodynamics During Exercise In Men
Bibliographic record
Abstract
High levels of respiratory muscle work may elicit a redistribution of blood flow from the locomotor to the respiratory muscles during exercise. It is unknown if specific inspiratory muscle training (IMT) can attenuate this response during high-intensity, whole-body exercise. PURPOSE: To examine the hemodynamic responses of multiple inspiratory muscles and the vastus lateralis (VL) during incremental cycling before and after 5 weeks of IMT. METHODS: After a comprehensive familiarization visit, 25 recreationally active healthy men (mean±SD; age=24±4; maximal aerobic power (V[Combining Dot Above]O2max)=52±10 ml·kg-1·min-1) completed two maximal incremental cycle exercise tests (25W/2min steps) separated by 5 weeks of pressure threshold IMT or sham-control training (SC). The IMT group (n=12) performed 30 inspiratory efforts twice daily against a minimum resistance of 50% of maximum inspiratory pressure (MIP), adjusted weekly. The SC (n=13) group performed a daily bout of 60 inspiratory efforts against 10% MIP using the same device with no weekly adjustments. During the incremental cycle tests, participants were instrumented with NIRS optodes on the sternocleidomastoid (SCM), parasternal intercostals (PIC), 7th intercostal space (7IC), and VL to measure changes in oxygenated, deoxygenated, and total hemoglobin (tHb) concentrations. RESULTS: The IMT and SC groups were well matched for age, height, mass, and V[Combining Dot Above]O2max. There was a significant increase in MIP in the IMT group (mean±SD, 135±44 vs. 159±35 cmH2O, p<0.05) but not in the SC group (134±39 vs. 134±44 cmH2O, p>0.05). No differences were detected when comparing pre vs. post-IMT for any NIRS derived variables at relative percentages of maximal work rate (20, 40, 60, 80,100%) for any muscle in both the IMT and SC groups. The tHb (muscle blood volume) at the highest equivalent absolute work rate achieved by an individual on each test in the IMT group (pre vs. post-IMT) was 3±15 vs. 1±25, 1±9 vs. 2±11, -6±12 vs. -6±12, and 12±10 vs. 11±9[INCREMENT]μM whereas the SC group was 2±11 vs. 3±6, 1±9 vs. 4±8, -6±6 vs. -6±8, and 12±8 vs. 9±10[INCREMENT]μM in the SCM, PIC, 7IC, and VL, respectively (all p>0.05). CONCLUSION: Five weeks of pressure-threshold IMT had no effect on respiratory or locomotor muscle hemodynamics during incremental cycle exercise in healthy recreationally active men. Supported 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 | 0.000 | 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) | 0.001 | 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".