Prior Exercise And Ischemia Affect Blood Flow And Oxygen Uptake During Subsequent Heavy Forearm Exercise
Bibliographic record
Abstract
Enhanced blood flow (BF) by prior exercise is associated with acceleration of muscle oxygen uptake (VO2musc) kinetics during subsequent heavy exercise. PURPOSE: We tested the influence of enhanced forearm BF by exercise and circulatory occlusion on VO2musc onset kinetics. METHODS: Seven varsity ice hockey players completed three heavy forearm exercise bouts (5-min at 30 % MVC 14.1 ± 1.2 kg) in two different sessions: [1] control, heavy exercise followed immediately by 2 minutes of circulatory occlusion; [2] heavy bout 8-min after control; [3] heavy bout 3-min after release of 5-min forearm occlusion that included 1-min moderate hand-grip exercise. BF was measured continuously using Doppler ultrasound and venous blood was sampled every 15 seconds from a deep forearm vein to determine O2 extraction. RESULTS: BF was elevated prior to bout [2] and [3] compared to the control at baseline ([2], 318.2 ± 51.7; [3], 282.1 ± 30.9 vs. control, 69.0 ± 13.4 mL/min, P< 0.01), however baseline VO2musc was significantly higher only prior to bout [2] (10.1 ± 2.6 vs. 4.0 ± 1.0 mLO2/min, P< 0.01). Neither BF nor VO2musc were different at end exercise among the three heavy bouts. BF and VO2musc were significantly higher during the first 2-min of bout [2] compared to both bout [3] and control. Prior occlusion slightly enhanced the onset BF and VO2musc kinetics during bout [3] with a significant increase at 45 sec compared to control (BF: 375.8 ± 75.4 vs. 312.9 ± 79.9 mL/min; VO2mus: 51.2 ± 15.9 vs. 41.9 ± 16.1 mLO2/min, P< 0.05). The calculated VO2mus area during the first two minutes of exercise was significantly greater in bout [2] than the areas of both bout [3] and control ([2], 113.9 ± 39.1 vs. [3], 93.7 ± 28.7; control, 84.3 ± 30.2 mLO2, P< 0.01). These results indicate a greater contribution from oxidative phosphorylation at the onset of a heavy bout that followed heavy exercise and occlusion compared to that which followed occlusion with moderate exercise. CONCLUSION: We employed two protocols which enhanced BF prior to a subsequent heavy exercise bout (heavy exercise followed by occlusion and moderate exercise during occlusion); however the major impact on oxidative metabolism was seen only following heavy exercise. Supported by Egyptian Culture and Educational Bureau in Canada and 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) | 0.002 | 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".