Effect Of Impact During High-intensity Interval Exercise On Bone Markers In Female Adolescents
Bibliographic record
Abstract
PURPOSE: The physical impact during exercise is considered the primary variable for enhancing bone properties during adolescence. Conversely, it has been suggested that high-intensity interval exercise (HIIE) may induce similar changes in bone markers regardless of the impact. Nevertheless, the effects of HIIE with and without impact on bone markers have not been investigated in adolescents. Thus, we aimed to examine the acute effect of HIIE performed with and without impact on bone markers of formation (i.e., P1NP) and resorption (i.e., CTX-I) in female adolescents. METHODS: Eleven adolescents at post-peak height velocity (PHV), aged 15 to 18.9 years, performed two HIIE (cycling and running) trials in random order (cross-over design). Each participant performed a progressive incremental test for each mode of HIIE. The maximal speed and power achieved in these tests were set as the workload for the HIIE trials. For each trial, participants completed 8 bouts of 1 minute of work separated by 1 minute of rest. Adolescents were instructed to have a standardized breakfast 1 hour before the exercise session and blood samples were taken before exercise, as well as 5 and 60 minutes after exercise. Serum concentrations of P1NP and CTX-1 were analyzed using a chemiluminescence assay. A two-way ANOVA with repeated measures, considering PHV and leg lean mass as covariates, tested the effects of the HIIE mode (running or cycling), time (pre, 5 min, 60 min post-exercise), and their interaction. RESULTS: A significant mode*time interaction was observed in P1NP (p = 0.005). In the running mode, P1NP significantly increased by 18% from 97.1 ± 39.9 mcg/L at baseline to 114.3 ± SD = 47.0 mcg/L at 5 min post-exercise, returning to baseline levels after 60 min while cycling did not induce any significant changes. Regarding CTX-1, no significant effects were observed in either running or cycling. CONCLUSION: HIIE associated with impact (running) induced significant changes in bone formation marker, which was not the case when HIIE was performed without impact (cycling), suggesting that the intensity of exercise alone does not seem to induce a significant bone response in adolescent females. Sao Paulo Research Foundation (FAPESP)
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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 | 0.001 |
| 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".