Physical and physiological differences of backs and forwards from the Brazilian National rugby union team
Bibliographic record
Abstract
BACKGROUND: The aim of this study was to compare backs and forwards rugby union players recruited to a National team in the following physical and physiological indicators: anthropometrics, squat jump (SJ), countermovement jump (CMJ), 10- and 30-meter sprint, resting heart rate variability (HRV), Yo-Yo Test and heart rate (HR) at 2 minutes of test. METHODS: The measurements were performed on the first day of a training camp planned to finely select the players who would participate in the 2016 America's Rugby Championship. The magnitude-based inference was used in the comparisons. RESULTS: Backs demonstrated almost certainly greater distance in the Yo-Yo Test (backs: 2305.9±231.3 meters; forwards: 1802.4±361.2 meters), higher vertical jump height in both SJ and CMJ (SJ: 44.0±5.3 cm vs. 37.6±5.4 cm; CMJ: 46.1±5.0 cm vs. 40.0±5.5 cm, for backs and forwards respectively), and superior sprint velocity in 10- and 30-m (10-m: 6.02±0.23 m.s-1 vs. 5.51±0.34 m.s-1; 30-m: 7.46±0.25 m.s-1 vs. 6.89±0.37 m.s-1, for backs and forwards respectively) than the forwards. In contrast, forwards were almost certainly taller and heavier than backs, and displayed higher sprint momentum in 10- and 30-meters (10 meters: 513.0±51.6 kg.m.s-1 vs. 598.4±53.1 kg.m.s-1; 30 meters: 635.3±56.1 kg.m.s-1 vs. 749.0±70.5 kg.m.s-1, for backs and forwards respectively). The submaximal HR in the first 2-minutes of the Yo-Yo test was likely lower in the backs than in the forwards (77.6±5.1% of the maximal HR vs. 81.3±5.4% of the maximal HR for backs and forwards respectively), while HRV indices were not different between backs and forwards. CONCLUSIONS: Playing position appears to be determined by the players' physical and physiological characteristics in top-level rugby union, and the submaximal HR measured during Yo-Yo test can be a simple alternative to discriminate backs and forwards.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".