Research Library

Introduces allostatic load as a way to understand the physiological costs that may accompany prolonged challenges.

Synthesis of human and animal research; no single trial sample

This conceptual review connects human and animal research to explain cumulative costs of adaptation. Specific intervention effects require corresponding human studies.

Explores the dual nature of adaptation through the protective and damaging effects of stress mediators.

Review; no single trial sample

The review focuses on protective and damaging mechanisms of stress mediators. Applying its account requires distinguishing mechanistic arguments, individual clinical assessment and specific intervention studies.

Fried and colleagues define a frailty phenotype using weight loss, exhaustion, weak grip, slow gait and low activity, with three or more criteria indicating frailty. Its associations with later death, hospitalisation and functional decline offer an operational framework for vulnerability in older adults; it does not directly measure dynamic recovery after a stressor.

5,317 community-dwelling CHS adults aged ≥65 in two recruitment cohorts; frailty prevalence was 6.9%.

Observational design, available cohort variables, some self-report and disease exclusions limit generalisation. Table 7 gives a three-year falls HR of 1.29 (95% CI 1.00–1.68), P=.054; not every endpoint was significant. Sex/body-size-specific thresholds require checking before application.

This study examines neurobehavioural and sleep-physiology changes during repeated sleep restriction and total sleep deprivation. This record currently provides the original-source and erratum entry points. Detailed estimates, model equations and quantitative interpretation are deferred until the formal 2004 erratum is checked.

Controlled experiments in healthy adults; this edition primarily provides a bibliographic record and correction notice.

PubMed confirms an erratum in Sleep 2004;27(4):600, but its text has not been obtained. The available 2003 PDF predates it. The correction cannot be assumed to be typographical or numerically immaterial, and the model is not used here to prescribe individual sleep duration.

Laboratory stressors do not elicit uniform cortisol responses. Social-evaluative threat combined with uncontrollability was associated with stronger responses. Pooled effects were d=.52 (95% CI .38–.66) for uncontrollable tasks and d=.16 (.03–.29) for controllable tasks, helping explain variation between studies.

208 experiments in 187 reports, involving 6,153 healthy adults and psychological stress tasks lasting no more than one hour.

Task characteristics overlap, so subgroup differences are not equivalent to randomized causal comparisons. Physical stressors, children and clinical populations were excluded; first laboratory exposure also limits everyday application. Peak response, total response and post-task recovery are distinct outcomes.

The perseverative-cognition hypothesis proposes that worry, rumination, anticipation and post-event processing can extend physiological activation beyond a stressor. It motivates measuring the event, repetitive thought and subsequent physiology together. The paper also notes that direct evidence for objective disease outcomes was limited.

Literature on worry, rumination and anticipatory stress; no new trial sample.

State and trait measures differ across this narrative review, which provides no single pooled effect. Perseverative cognition, general negative affect and causal pathways to chronic disease require separate tests.

The Recovery Experience Questionnaire distinguishes psychological detachment, relaxation, mastery and control during nonwork time, yielding 16 items in four factors. It provides a way to discuss and measure different experiences; questionnaire scores do not themselves measure physiological recovery.

991 returned questionnaires were randomly split; after missing-data exclusions, calibration and cross-validation each included 465 people, totalling 930. A construct-association subsample included 271.

Validation relied mainly on self-report and correlations. Factors overlap, particularly relaxation and control. Cross-language invariance, additional recovery experiences and incremental prediction of objective recovery trajectories require separate tests.

Proposes four ranges of physiological mediators: predictable regulation, responses to unexpected demands, overload and failure. The authors use changing boundaries to describe how history and context may alter an individual’s reactive scope.

Conceptual framework across comparative physiology; no single trial sample.

The model proposes changing response ranges and provides a structure for conceptual and comparative research. Translating ranges into human measurement thresholds requires system- and population-specific validation.

After five restricted nights, greater recovery sleep opportunity improved five of six neurobehavioural measures in a dose-related manner. Yet even a ten-hour opportunity did not restore sustained attention, subjective sleepiness and fatigue fully to baseline. Recovery depended on the outcome measured.

159 healthy adults: 142 in restriction and 17 controls, with smaller groups at each recovery dose.

A controlled single-night experiment cannot determine recovery after weeks of restriction, in clinical populations or for an individual. Time in bed differs from actual sleep, and comparisons with baseline differ from comparisons with controls.

Examines links between cardiovascular recovery after laboratory mental stress and later cardiovascular risk status.

Recovery analyses included 30 associations reported in 5 articles

Findings are based on prospective associations. Whether improving a recovery measure changes later risk requires investigation in intervention designs.

This review connects the allostatic-load framework with neuroendocrine, immune, metabolic and cardiovascular measures, illustrating why cumulative physiological risk is studied across systems.

Review of theoretical and empirical stress, health and cognition research; no single trial sample.

The review covers biomarkers with different meanings and collection methods. Using a panel requires specifying sampling conditions, marker selection and its relationship to the outcome of interest.

Discusses the relationships between stress, adaptation and brain plasticity.

Synthesis of human and animal research; no single trial sample

Evidence spans species and study designs. Mechanistic findings need to be connected with specific populations, exposures and outcomes when assessing their relevance to human interventions.

Among European workers, job strain—high demands combined with low control—was associated with subsequent coronary heart disease. The age/sex-adjusted HR was 1.23, falling to 1.17 (95% CI 1.05–1.31) after socioeconomic adjustment. This is prospective evidence linking working conditions with long-term health.

13 cohorts and 197,473 workers free of coronary disease at baseline, with 2,358 incident events.

Strain was mainly measured once at baseline, leaving possible residual confounding, changing exposure and reverse causation. Published and unpublished data gave different estimates. The reported population-attributable fraction assumes causality and is not a demonstrated intervention-preventable fraction.

Sterling argues that efficient regulation anticipates demand, coordinates resource allocation and learns from previous errors. Physiological adjustment and anticipatory behavior both contribute to this account.

Theory-led review drawing on physiological and behavioral examples; no single trial sample.

The paper develops predictive regulation as a theoretical account; its critique of homeostasis represents the author’s position. Read it alongside modern feedback and homeostatic theories, distinguishing physiological examples from broader theoretical inferences.

This coordinate meta-analysis links HRV with activity in regions including the anterior cingulate, extended amygdala and ventral striatum, informing the neurovisceral-integration account. Findings differed between emotional and cognitive/motor tasks, indicating that neural associations depend on context.

8 PET/fMRI studies, 191 participants and 10 contrasts.

The authors describe an illustrative rather than exhaustive selection. Studies were small and heterogeneous, with HRV recorded both inside and outside scanners. Spatial convergence and correlation do not establish a specific top-down causal mechanism or diagnose psychological traits.

Physical performance improved with protein supplementation; muscle mass did not.

65 frail older adults.

Findings come from an intervention trial in frail older adults. Physical performance and muscle mass are distinct outcomes; extension to other age or functional groups requires corresponding studies.

Protein distribution affected post-exercise muscle protein synthesis.

24 trained young men.

The study measured short-term muscle protein synthesis after exercise. Its findings apply to the training population, protein schedules and observation window studied; everyday fatigue and sustained functional change require separate measurement.

Billman examines the assumptions needed to interpret LF/HF as cardiac sympathetic–vagal balance. LF is not a purely sympathetic signal, HF is influenced by respiration and mechanical effects, and autonomic branches do not always vary reciprocally or linearly. Similar ratios can therefore arise from different physiological processes.

Existing physiological experiments and mathematical arguments; no new patient cohort.

The critique targets this particular interpretation of LF/HF, not all information carried by HRV. Other measures require assessment of their own physiological basis, breathing, heart rate and recording conditions.

Recovery differed across outcomes after mild sleep restriction. After two extended nights, IL-6 was not significantly different from baseline and sleepiness/fatigue improved, but sustained-attention performance did not recover. Twenty-four-hour cortisol had not significantly increased during restriction, so its subsequent fall is not evidence that all stress measures returned together.

30 healthy adults, 16 men and 14 women, in a fixed-sequence within-person experiment.

Without an external control, sequence, practice, earlier awakening and daytime activity may confound results. A nonsignificant baseline difference is not an equivalence test. Findings apply to the measured outcomes and recovery window.

Mouse experiments linked natural sleep and anaesthesia with extracellular space, cerebrospinal-fluid influx and tracer clearance. The study measured both influx and clearance of cortically injected radiolabelled amyloid-β and inulin; faster amyloid-β clearance during sleep provides mechanistic evidence concerning brain solute transport.

Awake, naturally sleeping and anaesthetised mice, with experiment-specific subsamples and repeated measurements.

Invasive procedures, state, timing, anaesthetic and tracer molecules matter. Injection routes, molecules and estimation differ from Miao and colleagues' 2024 study, so one result cannot simply replace the other. Mouse mechanisms do not directly quantify human catch-up-sleep benefits.

Resting, exercising and post-exercise heart-rate measures answer different questions. Buchheit emphasises standardising timing, posture and exercise conditions, then comparing changes with measurement error, individual variability and training context alongside subjective and other functional measures.

Methodological review drawing mainly on endurance-sport research; no single intervention sample.

Cardiac autonomic recovery does not establish muscle, glycogen or whole-body recovery. Error varies substantially across measures and conditions. The review supplies no universal consumer HRV threshold, and its cited statistical decision methods require appraisal for each application.

Ramsay and Woods examine homeostasis and allostasis through specific mechanisms: feedback and feedforward control, coordination between effectors, and dysregulation through overshoot, persistent activation or competing effectors. Their account helps turn a terminology debate into physiological questions that can be specified.

Physiological theory and experimental literature; no new clinical sample.

This is a conceptual critique, and its definition of allostasis differs from other accounts. Mechanistic examples do not estimate intervention effects, and the authors' terminology should not be treated as a field-wide consensus.

A multidisciplinary discussion presents resilience as functioning and adaptation over time in the context of adversity. It highlights influences at individual, family, community and cultural levels.

Expert perspectives from psychology, psychiatry, developmental science and social context research; not a single empirical sample.

Definitions vary across disciplines and levels of analysis. Interpreting adaptation requires considering demands and resources in individual, family, community and cultural contexts.

Connects research on job demands, psychological detachment and recovery.

Review of occupational psychology research; no single trial sample

The framework concerns work demands and recovery from work. Extension to sleep, cardiovascular or exercise research requires the definitions and measures of those domains.

Across experimental and correlational studies, perseverative cognition was linked to differences in cardiovascular measures, cortisol and HRV. Associations depended on the parameter, design and measurement conditions.

60 eligible studies of physiological correlates of perseverative cognition in healthy participants.

Experimental induction and observational designs support different levels of inference, with variation in measurement conditions and outcomes. Pooled results should be read by physiological measure and design.

Unfinished goals were harder to disengage from; planning helped employees prone to difficulty detaching.

Employees; longitudinal and experimental components.

Detachment outcomes do not establish physiological recovery.

The review frames physical resilience around resistance and recovery after a health stressor, distinguishing it from reserve available beforehand. Only 19 of 49 included papers explicitly defined the construct, and only one was an intervention study. Its main contribution is conceptual organisation and candidate measurement approaches.

English-language literature involving adults aged 65 or older: 49 papers from 1,078 abstracts, including 18 longitudinal, eight cross-sectional and 16 conceptual papers or letters, among other designs.

Searching for resilience with age/language restrictions may miss work using terms such as recovery. Conceptual coding requires interpretation. There was no pooled effect or validation of a universal scale; frailty, reserve and observed recovery trajectories remain distinct.

Flatter diurnal cortisol slopes were modestly associated with poorer health: pooled r=.147 (95% CI .112–.183), and r=.138 (.005–.267) in prospective studies. These results support research on diurnal rhythms and health, not diagnosis of an individual's stress from a single measurement.

80 studies with 179 associations spanning mental and physical health outcomes.

Heterogeneity was high (I²=83.23%); effect conversion, adjustment and publication-bias handling varied. The bias-adjusted mortality HR was 1.69 (.55–5.2), crossing 1 although the text calls it significant. This unresolved inconsistency prevents a claim of a robust significant mortality association.

Combining macaque tracing literature with human resting-state connectivity, the study proposes a large-scale system supporting allostasis and interoception. In a separate human sample, connectivity was associated with correspondence between subjective arousal and skin-conductance responses to images, providing correlational support for the proposed network.

Discovery sample of 280 and replication sample of 270; 41 of 66 participants in the validation study had usable imaging and skin-conductance data.

Functional connectivity does not establish direct anatomical connections or causal regulation. Vascular effects, brainstem resolution, cross-species mapping and sample selection constrain interpretation. Energy expenditure, allostatic load and individual recovery scores were not directly validated.

These recommendations distinguish resting, reactivity and recovery measurements. Raw ECG, recording length, artefact handling and respiration all affect interpretation. Recordings shorter than the commonly used five-minute window need metric-specific validation of comparability.

Methodological recommendations for psychophysiological HRV research; no new clinical trial sample.

Monitoring respiration does not imply automatic respiratory adjustment for every resting spontaneous-breathing recording; task-related breathing changes require care. Reporting guidance does not validate a device or clinical predictor, and filter settings cannot be transferred without checking.

With retained salary and funding for additional staff, reduced worktime was associated at 18 months with approximately 23 more minutes of diary-reported sleep on workdays and less perceived stress and sleepiness. The effect concerns this combined arrangement, not every possible four-day-week policy.

33 workplaces and 580 analysed participants: 354 intervention and 226 control, 76% women. Of 919 initially included, 98 withdrew after allocation and further analysis criteria were applied.

One workplace was assigned nonrandomly to control because of recruitment conditions. Post-allocation adherence/follow-up criteria mean this is not a complete intention-to-treat analysis. Self-reported diaries, clustering and selective retention constrain interpretation.

Detachment from work was associated on average with less exhaustion and better self-reported sleep: exhaustion r=−.36 (95% CI −.42 to −.30), sleep r=.30 (.22–.38). Physiological activation was represented by only three studies and 219 people, with pooled r=.03 (−.12 to .17), showing no clear association.

86 publications, 91 independent samples and 38,124 employees; outcome-specific subsets differed.

Most evidence used self-report and between-person correlations; diary data were also aggregated to between-person estimates. Sleep heterogeneity was high (I²=94.55%), with a prediction interval of −.09 to .61. An average association does not establish the effect of increasing detachment within one person.

Meal-challenge responses distinguished metabolic groups beyond fasting measurements.

40 men: 20 healthy and 20 with type 2 diabetes.

This exploratory study compares metabolic responses between groups. It contributes a challenge-testing method; intervention effects require appropriately controlled intervention studies.

Considers training, competition and other life demands together with recovery, individual variation and ongoing monitoring.

Multidisciplinary expert consensus; not a single athlete trial

The consensus integrates research and practical judgments in sport. Effects of a specific recovery strategy should be assessed through intervention evidence for the relevant population, protocol and outcomes.

The paper proposes studying resilience through dynamics: slower recovery may accompany changes in variance, temporal autocorrelation or correlations between subsystems. These are testable ideas, but simulations and findings cited from other papers are not new human clinical validation by this article.

Human, animal and complex-system literature and models; no new unified patient cohort.

Critical slowing depends on assumptions about near-equilibrium behaviour and perturbations and does not cover every cyclic, chaotic or abrupt transition. Noise, changing external disturbances and treatment can alter the same indicators. High autocorrelation alone does not establish declining resilience.

In this short laboratory protocol, two unrestricted weekend nights followed by renewed restriction did not prevent the observed metabolic dysregulation. Whole-body insulin sensitivity fell by approximately 13% and 27% from each group's own baseline in continuous restriction and weekend recovery respectively. Those within-group percentages do not establish a significant between-group difference.

36 young, normal-weight healthy adults, 18 women and 18 men: eight controls, 14 continuous-restriction and 14 weekend-recovery participants.

The sample and duration were limited, while sleep, intake, weight and circadian timing changed together. The weight-adjusted weekend-recovery analysis had P=.054. Differences between adjusted and unadjusted results matter; the experiment does not establish that every form of catch-up sleep is without value.

The paper describes three approaches to recovery potential: trajectories after a stressor, standardized stimulus-response tests and recovery from everyday small perturbations. An updated search included 27 studies, 26 concerning recovery after functional decline; most still relied on static reserve measures and binary recovery outcomes.

Research on older adults' recovery potential, particularly with multimorbidity, extending an earlier review.

Recalled pre-stressor status, sparse measurements, unclear stressor intensity and concurrent disturbances limit comparison. Links between a subsystem and whole-person function need validation. The authors consider dynamic measures insufficiently validated for routine implementation in clinical guidelines.

Relative lean mass improved more with protein, without additional strength or performance gains.

116 active older adults with relatively low habitual protein intake.

The study concerned physically active older adults, with different findings for body composition and function. Benefits should be reported separately for lean mass, strength and physical performance.

Among frail or prefrail older colorectal-cancer patients, preoperative prehabilitation showed no clear advantage over postoperative rehabilitation for 30-day complication burden: adjusted CCI difference −3.2 (95% CI −11.8 to 5.3). The four-week walk-distance difference of 18.5 m (−20.2 to 57.3) was also nonsignificant. The intervals still allow meaningful benefit and do not demonstrate equivalence or no effect.

Two centres; patients aged ≥65 with Fried scores ≥2. Of 120 randomized, 110 entered the authors' intention-to-treat analysis.

Ten post-randomization exclusions, substantial secondary-outcome missingness, age/ASA imbalance and the missing-at-random imputation assumption matter. Population, comparator and implementation differ from PREHAB, so the trials are not simply opposing positive/negative results. A formal correction concerns author affiliations, not result values.

This whitepaper distinguishes cognitive reserve, brain reserve and brain maintenance, giving researchers a shared vocabulary for different explanations of preserved cognitive function.

Expert workgroup definitions and research guidance in cognitive aging and dementia.

The definitions concern cognition and brain research. Comparisons with other organ functions or physical capacity should retain domain-specific definitions of capacity and outcomes.

The study constructs a blood-count-based DOSI and examines age-related changes in its autocorrelation. Age-group correlation times of roughly 2–8 weeks motivate dynamic ageing markers. The proposed 120–150-year limit comes from extrapolation beyond observed ages, not direct measurement of a human lifespan limit.

NHANES modelling and UK Biobank validation; 1,082 people with longitudinal blood counts, reduced to 407 for the DOSI-selected non-frail dynamic analysis, plus separate activity data.

Some longitudinal data lack clinical status, and selection on DOSI affects interpretation. Group-average autocorrelation is not an individual's observed recovery after a defined stressor. Linear extrapolation into unobserved ages cannot establish a hard biological limit.

This meta-analysis separates recovery activities, experiences and states. Their relationships with work demands, resources, well-being and performance differed, showing why one definition cannot simply stand in for the others.

Meta-analysis using 198 empirical samples across employee-recovery research.

Recovery activities, experiences and states overlap only partly. Pooled associations are limited by study designs; comparisons with other reviews should also identify overlapping samples.

Micro-breaks of up to ten minutes showed small average benefits for vigour and fatigue: vigour d=.36 (95% CI .16–.55), fatigue improvement d=.35 (.19–.50). The primary performance estimate, d=.16 (−.04 to .37), was not significant; subjective improvement does not establish better work performance.

19 reports, 22 independent samples and 2,335 healthy employees or students, synthesised separately by outcome.

Activities, tasks and designs varied; inclusion required English, a specified publication period and accessible full text. Performance showed a publication-bias signal, and sensitivity estimates do not replace the main analysis. Its P value is .17 in the text and .116 in Table 3; both are nonsignificant, but the exact value remains unresolved.

Compares approaches to measuring allostatic load and considers how relevant databases can be used in neighbourhood research.

18 reviews covering 238 studies

Included reviews differed in biomarker selection and scoring. Comparing indices requires examining their components, thresholds, populations and appraisal methods.

Higher allostatic load was associated with higher all-cause and cardiovascular mortality in pooled observational evidence. The size of the association varied substantially between studies.

Systematic review of 17 eligible studies. Main pooled estimates used 10 studies for all-cause mortality and six for cardiovascular mortality.

Heterogeneity was high for most pooled estimates, with I² above 90%. Results describe associations with mortality; intervention benefits and individual risk prediction require separate evaluation.

This review follows recovery across work breaks, evenings, weekends and vacations. It connects these opportunities with work conditions, boundaries between work and non-work life, and evidence from field and intervention studies.

Integrative review of work-recovery research, emphasizing daily and longitudinal field studies.

Evidence varies across settings and time scales. Well-being, performance and physiological change need separate interpretation, and effects of particular breaks depend on study conditions.

Brief daily breathing practice, particularly cyclic sighing, showed relative benefits for positive affect and respiratory rate. Between-group differences in negative affect and state anxiety were not significant, and HRV, resting heart rate and sleep did not change significantly. Mood benefits should be read alongside these null physiological findings.

Remote exploratory trial of 108 people: mindfulness 24, cyclic sighing 30, box breathing 21 and cyclic hyperventilation with retention 33. Figure 4 physiological analyses included 100.

Small groups, remotely estimated adherence, retrospective registration and no long-term follow-up constrain interpretation. Eight households received the same condition; consequences for statistical independence remain to be checked. Within-group improvement does not replace a between-group comparison.

Presents a shared NIH resilience framework linking a specified system and challenge to responses over time. Resistance, adaptation, recovery and growth are possible outcomes to investigate.

Cross-domain conceptual framework; no single participant sample.

The framework helps specify systems, stressors and resilience research questions. Applying it to a measure or intervention requires evidence matched to the population, outcomes and design.

This multi-cohort analysis narrows the candidate markers for allostatic-load measurement. A five-marker combination—CRP, resting heart rate, HDL cholesterol, waist-to-height ratio and HbA1c—performed similarly to longer combinations for mortality prediction within the study. Peak expiratory flow offered additional information. The contribution is a candidate set for harmonisation.

13 cohorts with 67,126 participants aged 40–111; mortality information was available in 10 cohorts.

Cohorts were selected by data availability. Most health outcomes were cross-sectional, and mortality follow-up varied. Selection against health outcomes does not establish stress specificity or an individual diagnostic threshold. Younger populations, medication effects, sex differences and external calibration require further evaluation.

In PREHAB, four weeks of multimodal prehabilitation was associated with fewer severe complications, defined as CCI>20: 21/123 versus 38/128, adjusted OR=.47 (95% CI .26–.87). The other coprimary outcome, six-minute walk distance four weeks after surgery, differed by 15.6 m (−1.4 to 32.6), which was not significant. These outcomes require separate interpretation.

Seven centres and nonmetastatic colorectal-cancer surgery patients; 269 randomized, 18 excluded after randomization and 251 in the authors' intention-to-treat analysis. Median age was 69.

The planned sample was 714, but COVID-19 stopped recruitment early. CCI was analysed dichotomously because of skew, and about one-third of four-week walking data were missing. A 2023 correction added significance superscripts to the prehabilitation group's preoperative and four-week Figure 3D data. Eight-week secondary results do not replace the four-week coprimary endpoint.

The framework distinguishes adaptable from problematic low energy availability and considers health and performance together.

Consensus concerning female and male athletes.

A clinical framework, not a diagnostic rule based on one missed meal or a consumer-calculated energy value.

Lower energy availability reduced integrated muscle protein synthesis.

30 trained, eumenorrheic women randomized.

Short, controlled exposure in trained women; protein synthesis is not a whole-body recovery outcome.

Low availability impaired performance; the time-trial impairment persisted after three refueling days.

12 female endurance athletes; randomized crossover.

Small athlete sample; energy and nutrient availability changed together. Immune-cell measures do not establish clinical illness.

In CHARLS participants aged 45 and older, higher baseline allostatic load and increases over time were associated with subsequent cardiovascular disease and all-cause mortality.

Analysis of the China Health and Retirement Longitudinal Study; outcome-specific sample counts are not stated in the abstract used for this note.

The observational design limits causal interpretation, and cardiovascular disease was based on self-reported physician diagnosis. Findings should be interpreted within the study’s age range and follow-up conditions.

This mouse study found similar diffusion coefficients across the tested states but estimated reduced tracer clearance during recovery sleep and the anaesthetic conditions studied. It highlights the need to distinguish diffusion, distribution and clearance and to compare the actual experimental methods.

Male C57/BL6 mice aged 3–7 months, with different subsamples for diffusion and clearance measurements.

Sleep followed five hours of deprivation. Most procedures were unblinded, no advance sample-size calculation was performed, and exclusions included failed fits. Methods differ from Xie's 2013 study. A formal 2024 correction fixed the Figure 3b source-data column Mean Wake 3h. This note does not independently reproduce Figure 3b; data reuse requires the publisher's current corrected file.

More regular sleep was associated with lower all-cause mortality. In models including regularity alone, the highest versus lowest quintile HR changed from .52 (95% CI .45–.60) with minimal adjustment to .70 (.59–.83) with full adjustment; including sleep duration yielded .74 (.62–.89). This motivates attention to regularity but does not establish the effect of changing sleep schedules.

UK Biobank accelerometry cohort with 1,859 deaths. The abstract/discussion gives 60,977 people, while the characteristics section gives 60,997; this discrepancy remains unresolved. Minimal/full models included 60,780/46,721.

Observational design, one-week measurement, a relatively homogeneous middle/older-age sample and residual confounding constrain inference. Full adjustment also reduced the sample, so attenuation cannot be attributed entirely to covariates. Associations do not establish calibrated individual prediction.

A workflow and repository make the construction of a five-marker allostatic-load index inspectable across secondary datasets. The preprint describes the workflow; TAP separately tested sensitivity to reference populations and scoring rules in NHANES 2015–2016.

Secondary-data workflow covering All of Us, HRS and NHANES; these are separate source populations, not one pooled validation cohort.

This methodological preprint focuses on constructing indices and analysis workflows from secondary data. Individual thresholds, responsiveness and predictive performance require dedicated validation. Reuse should identify both the paper and repository version because the code continues to change.

Five wearables showed differing agreement with a chest-strap ECG reference for nocturnal HRV. Reported concordance correlation coefficients were .87 for Garmin, .97 for Oura 3, .99 for Oura 4, .82 for Polar and .94 for WHOOP. This assesses basic nocturnal measures, not manufacturers' composite recovery scores.

13 healthy adults contributing 536 nights; valid nights differed by device and are not independent participant counts.

Sampling windows and algorithms differ, and nights are repeated within people. Table 3 reports Polar bias of −4.65 ms but limits of −14.30 to 23.60 ms, whose midpoint is +4.65 ms. The original PDF shows the same values; difference direction remains unresolved, so these limits should not define a precise device threshold.

Composite scores differed in inputs and calculation approaches, with limited transparency and validation evidence.

14 composite scores across 10 wearable manufacturers.

A documentation-based review, not an independent trial of every device or subsequent software version.

Proposes an active-inference account of allostasis and four resilience phenotypes. Environment, prediction and actions that shape the environment are central to the explanation.

Hypothesis and Theory article; not a trial validating four human categories.

The four phenotypes are theoretical categories for empirical testing. The paper contributes models and research questions; clinical classification would require further evaluation.

After-hours work connectivity may be associated with both greater autonomy and less detachment. The correlation-based model estimated indirect paths through autonomy of about .05 for both work–family balance and task performance; paths through detachment were −.18 and −.03 respectively. These are statistical pathways pointing in different directions.

71 sources and 283 effects: 68 original-study reports plus three previous meta-analyses, not 71 independent primary studies. Samples differed by outcome.

Correlation-based mediation cannot establish temporal order or causality. Main-model RMSEA=.14 indicates limited fit; mixed designs, report overlap and possible nonlinearity also matter. Findings do not establish that after-hours connectivity is invariably beneficial or harmful.

This commercial-wearable cohort separates between-person, within-person and cross-lagged associations. Some physiological and mental-health measures were associated concurrently, but physiological predictors of subsequent mental health were not significant in the cross-lagged analyses. Some earlier stress measures predicted later physiology. Concurrent association is not a validated prediction tool.

181,574 WHOOP users and approximately 7.94 million wear-days; questionnaire samples varied, and heart-rate-zone activity analyses involved only about 3,196 users.

Device purchase and continued use, recall-based questionnaires and unmeasured environmental or menstrual factors affect interpretation. Person-mean centring does not remove all time-varying confounding. External prospective prediction and calibration remain necessary.

The paper makes allostatic-load data cleaning, marker selection and scoring more reproducible, applying a shared workflow separately to All of Us, HRS and NHANES. Its main contribution is traceable measurement choices rather than validation of a new clinical score.

Three databases analysed separately; the All of Us workflow included 37,866 people. Individual records were not pooled across databases.

Within-sample quantiles depend on population and measurement. Table 9 lists CRP cutoffs of 14.20, 4.29 and 4.14, with a coefficient of variation of 0.7638; their relationship to the text's heterogeneity summary needs clarification of units and scope. This unresolved discrepancy is not a formal correction and does not establish interchangeable thresholds.

The authors propose minimum reporting items for human and animal HRV research: recording conditions, raw signals, windows, respiration, artefacts, frequency bands, nonlinear parameters, software and statistics. Animal work additionally requires species, anaesthesia, temperature and postoperative recovery conditions.

Human and animal HRV methods literature; no new data-analysis sample.

This is a narrative methodological review and author-proposed checklist. The consulted text did not describe Delphi consensus or external validation. Complete reporting improves inspectability but does not itself establish device validity, physiological specificity or useful clinical prediction.

Mortality associations differed across restriction/rebound patterns; rebound groups were not significantly different from regular sleep.

85,618 UK Biobank participants; replication in 4,586 NHANES participants.

Observational; rebound is not specifically weekend sleep. Non-significance does not establish equivalence or causation.

This scoping review examines what definitions of physical resilience assume about systems, perturbations and time. The authors propose a more explicit conceptual framework to help align future measurement.

Scoping review of experimental and conceptual physical-resilience literature in gerontology and rehabilitation.

This conceptual proposal emphasizes definitions of systems, disturbances and recovery. Proposed measures and their applicability across domains require empirical study.

Blood pressure and triglycerides were higher after restriction/recovery than habitual sleep.

10 healthy adults; randomized crossover.

Small pilot; weekend sleep duration did not differ between conditions. The experiment does not isolate a prescribed extra-sleep dose.