Hormonal and metabolic responses across phases of combined oral contraceptive use and menstrual cycle in young elite female athletes
Bibliographic record
Abstract
PURPOSE: Despite the significant number of female athletes using combined oral contraceptives (COCs), there is scant literature on their hormonal and metabolic effects across different phases. METHODS: In order to contribute to a wider knowledge of COC-action mechanisms involved in athletes' performance and health, we therefore examined the effects of low-dose monophasic COC (ethinylestradiol/levonorgestrel) intake on sex hormones (estradiol, progesterone, sex hormone binding protein (SHBG)) as well as on a large number of pituitary (LH, TSH, prolactin) and peripheral (triiodothyronine, cortisol, DHEA, DHEA-S, aldosterone, osteocalcin, 25(OH)D) basal hormone levels in nine young elite female athletes, across COC administration (first and second half of active hormone intake, washout phases), compared to eleven female athletes without hormonal contraception across their normal menstrual cycle (NMC, i.e., early follicular, end follicular/peri-ovulatory, mid-luteal phases). RESULTS: COC vs. NMC increased SHBG (p < 0.01), TSH, cortisol and 25(OH)D (p < 0.05), and decreased DHEA and DHEA-S (p < 0.05) concentrations. Across COC and NMC phases, higher estradiol and aldosterone concentrations (p < 0.05) were observed during the washout and mid-luteal phases, respectively. CONCLUSION: In highly trained female athletes, COC vs. NMC induced several hormonal alterations, irrespective of the phases, leading to potential ergogenic and clinical repercussions that merit clarification. In NMC athletes, the impact of endogenous sex hormone fluctuations on the parameters studied appeared limited, perhaps mitigated by intense physical training, with only aldosterone change. Given the high prevalence of vitamin D insufficiency, it seems warranted to monitor this parameter, not yet routinely considered in female athletes, taking into account COC intake. TRIAL REGISTRATION: ID-RCB:2020-A02965-34, France.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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".