Case studies in physiology: Impact of a long‐distance hike on the Pacific Crest Trail on arterial function and body composition in a highly fit young male
Bibliographic record
Abstract
The Pacific Crest Trail (PCT) is a 4265-km hiking trail that extends from the US-Mexican border to the US-Canadian border through the mountain ranges of western North America. Individuals who hike the entire length of the trail in one season (4-6 months) perform long daily exercise durations while exposed to extreme environmental temperatures, high altitudes, intense solar radiation, and the consumption of calorie-rich, nutrient-poor diets. This case study reports changes in arterial function and body composition in a subject before and after a 112-day long-distance hike of the PCT. Brachial artery flow-mediated dilation, a measure of vascular endothelial function, decreased from: 6.97% to 5.00%. Carotid-femoral pulse wave velocity, a measure of aortic stiffness, increased from 5.39 to 5.76 m/s. Dual-energy x-ray absorptiometry scans detected no major changes in total-body bone mineral density, fat mass, or lean mass, although there were minor, unfavorable changes in some subregions of the body. It is important for individuals completing a long-distance hike to be aware of the potential deleterious changes associated with large volumes of exercise and consuming a high-calorie, low-quality diet.
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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 | 0.000 | 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) | 0.000 | 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".