The Effects of Simulated Altitude on Maximal and Submaximal Exercise
Bibliographic record
Abstract
The maximal lactate steady state (MLSS) identifies the upper limit of sustainable exercise; however, the extent to which an individual’s MLSS is affected by changes in altitude is unknown. The primary objective of this thesis was to determine the extent to which the MLSS-associated cycling power output (PO) (MLSSp), assessed in normoxia (NORM; FIO2=20.9 %) at 1111 m in Calgary, AB, is affected by acute exposure to simulated hypoxia (HYPO; FIO2=18.2 %) and hyperoxia (HYPER; FIO2=23.8 %). The secondary objective was to evaluate metabolic, cardiorespiratory, perceptual and neuromuscular responses to 30 min of cycling at similar relative intensities (i.e., MLSSp, and 10 W above the MLSSp (MLSSp+10)), and the same absolute intensity of exercise (i.e., the normoxic MLSSp; MLSSpNORM) in these same FIO2 conditions. Eleven (4 females, 7 males) participants completed this study. MLSSp decreased in HYPO (209±54 W) compared to NORM (225±58 W; p=0.001), but HYPER (230±56 W; p<0.001) was not different from NORM (p>0.05). Four participants reached task failure prior to 30 min in the HYPO condition at MLSSpNORM, in addition to two, three and three participants in NORM, HYPO and HYPER, respectively, at MLSSp+10. At MLSSp and MLSSp+10 blood lactate concentration ([BLa]), ventilation (V?E), heart rate (HR) and perceptual responses to exercise did not differ between FIO2 conditions (p>0.05), despite a difference in V?O2 (p<0.05). In contrast, at MLSSpNORM, V?O2 was similar across conditions (p>0.05), whereas [BLa], V?E, HR and perceptual response to exercise were exacerbated in HYPO compared to both NORM and HYPER (p<0.05). Exercising in each condition elicited neuromuscular fatigue—manifesting as a reduction in quadriceps isometric maximal voluntary contraction, high- and low-frequency doublet, and single twitch force amplitudes—but no differences were detectable between conditions at any exercise intensity (p>0.05). In summary, a small decrease in FIO2, relative to ambient conditions, reduced the cycling MLSSp and exacerbated metabolic, cardiorespiratory and perceptual responses to ~30 min of exercise at an absolute PO but not at similar relative intensities, whereas increasing the FIO2 by the same amount did not significantly affect MLSSp or physiological responses to exercise performed at the same absolute or relative intensities.
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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".