Changes in VO2max after 6 wk of Intensity Domain-Specific Training: Role of Central and Peripheral Adaptations
Bibliographic record
Abstract
PURPOSE: This study characterized central and peripheral adaptations to domain-specific endurance exercise training. METHODS: Eighty-four young healthy participants were randomly assigned to age- and sex-matched groups of: continuous cycling in the 1) moderate-intensity (MOD), 2) lower heavy-intensity (HVY1), and 3) upper heavy-intensity (HVY2) domain; interval cycling in the 4) severe-intensity domain (i.e., high-intensity interval training (HIIT), and 5) extreme-intensity domain (i.e., sprint-interval training (SIT)); or 6) control (CON). Two 3-wk phases of training (three sessions per week) were performed. All training protocols, except SIT, were work matched. RESULTS: Maximal oxygen uptake (V̇O 2max ), maximal cardiac output (Q˙ max ), derived maximal arterial-venous oxygen difference (a-vO 2diff ), blood volume (BV), plasma volume (PV), and near-infrared spectroscopy (NIRS)-derived muscle oxidative capacity (τOxCap) were measured and compared at PRE and POST. The largest change in V̇O 2max occurred in HIIT (0.43 ± 0.20 L·min -1 ), which was greater than CON (0.02 ± 0.08 L·min -1 ), MOD (0.11 ± 0.19 L·min -1 ), HVY1 (0.24 ± 0.18 L·min -1 ), and SIT (0.28 ± 0.21 L·min -1 ) ( P < 0.05) but not HVY2 (0.36 ± 0.14 L·min -1 ) ( P > 0.05). Changes in Q˙ max were observed in HVY1 (1.6 ± 0.5 L·min -1 ), HVY2 (3.0 ± 0.6 L·min -1 ), HIIT (2.9 ± 1.2 L·min -1 ), and SIT (1.8 ± 1.4 L·min -1 ) ( P < 0.05) but not in MOD (1.2 ± 0.3 L·min -1 ) and CON (0.1 ± -0.5 L·min -1 ) ( P > 0.05). HVY2 and HIIT produced significant changes in BV (438 ± 101 and 302 ± 38 mL) and PV (198 ± 92 and 158 ± 51 mL), respectively ( P < 0.05), whereas other groups did not. CONCLUSIONS: No significant peripheral adaptations (i.e., τOxCap and a-vO 2diff ) were observed in any group ( P > 0.05). The results indicate that higher training intensities (i.e., HVY2 and HIIT) produce larger changes in V̇O 2max , which is supported predominantly by central adaptations. In addition, results suggest that, despite nonsignificant changes, the contribution of peripheral components to changes in V̇O 2max should not be dismissed.
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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".