The effect of hypoxia and exercise on heart rate variability, immune response, and orthostatic stress
Bibliographic record
Abstract
Hypoxia with exercise is commonly used to enhance physiological adaptation in athletes, but may prolong recovery between training bouts. To investigate this, heart rate variability (HRV), systemic immune response, and response to an orthostatic challenge were measured following exercise in hypoxia and air. Eleven trained men performed a 10-km cycling time trial breathing hypoxia (16.5 ± 0.5% O(2)) or air. HRV and the heart rate response to an orthostatic challenge were measured for 3 days before and after each trial, while venous blood samples were collected pre-, 0, 2, and 24 h post-exercise. Hypoxia had no significant effect compared with air. Subgroup analysis of those who had a drop in oxyhemoglobin saturation (SpO(2)) > 10% between hypoxia and air compared with those who did not, demonstrated a significantly altered HRV response (△HFnu: -2.1 ± 0.9 vs 8.6 ± 9.3, △LFnu: 2.1 ± 1.0 vs -8.6 ± 9.4) at 24 h post-exercise and increased circulating monocytes (1.3 ± 0.2 vs 0.8 ± 0.2 × 10(9) /L) immediately post-hypoxic exercise. Exercise and hypoxia did not change HRV or the systemic immune response to exercise. However, those who had a greater desaturation during hypoxic exercise had an attenuate recovery 24 h post-exercise and may be more susceptible to accumulating fatigue with subsequent training bouts.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.007 | 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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".