Moderate-Intensity Intermittent Work in the Heat Results in Similar Low-Level Dehydration in Young and Older Males
Bibliographic record
Abstract
Older individuals may be more susceptible to the negative thermal and cardiovascular consequences of dehydration during intermittent work in the heat. This study examined the hydration, thermal, and cardiovascular responses to intermittent exercise in the heat in 14 Young (Y, Mean ± SE; 25.8 ± 0.8 years), Middle-age (MA, 43.6 ± 0.9 years), and Older (O, 57.2 ± 1.5 years) healthy, non-heat acclimated males matched for height, mass, body surface area, and percent body fat. Rectal temperature (Tre), heart rate (HR), local sweat rate (LSR), and hydration indices were measured during 4 × 15-min moderate to heavy cycling bouts at 400 W heat production, each followed by a 15-min rest period, in Warm/Dry (35°C, 20% relative humidity [RH]) and Warm/Humid (35°C, 60% RH) heat. No differences were observed between the age groups for Tre, Tre change, HR, LSR, mass change, urine specific gravity, and plasma protein concentration in either condition, irrespective of the greater level of thermal and cardiovascular strain experienced in the Warm/Humid environment. Plasma volume changes (Dry Y: -5.4 ± 0.7, MA: -6.2 ± 0.9, O: -5.7 ± 0.9%, Humid Y: -7.3 ± 1.0, MA: -7.9 ± 0.8, O: -8.4 ± 1.0%) were similar between groups, as were urine specific gravity and plasma protein concentrations. Thus, physically active Young, Middle-age, and Older males demonstrate similar hydration, thermal, and cardiovascular responses during moderate- to high-intensity intermittent exercise in the heat.
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 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".