Attrition from longitudinal ageing studies and performance across domains of cognitive functioning: an individual participant data meta-analysis.

OBJECTIVES: This paper examined the magnitude of differences in performance across domains of cognitive functioning between participants who attrited from studies and those who did not, using data from longitudinal ageing studies where multiple cognitive tests were administered. DESIGN: Individual participant data meta-analysis. PARTICIPANTS: Data are from 10 epidemiological longitudinal studies on ageing (total n=209 518) from several Western countries (UK, USA, Mexico, etc). Each study had multiple waves of data (range of 2-17 waves), with multiple cognitive tests administered at each wave (range of 4-17 tests). Only waves with cognitive tests and information on participant dropout at the immediate next wave for adults aged 50 years or older were used in the meta-analysis. MEASURES: For each pair of consecutive study waves, we compared the difference in cognitive scores (Cohen's d) between participants who dropped out at the next study wave and those who remained. Note that our operationalisation of dropout was inclusive of all causes (eg, mortality). The proportion of participant dropout at each wave was also computed. RESULTS: The average proportion of dropouts between consecutive study waves was 0.26 (0.18 to 0.34). People who attrited were found to have significantly lower levels of cognitive functioning in all domains (at the wave 2-3 years before attrition) compared with those who did not attrit, with small-to-medium effect sizes (overall d=0.37 (0.30 to 0.43)). CONCLUSIONS: Older adults who attrited from longitudinal ageing studies had lower cognitive functioning (assessed at the timepoint before attrition) across all domains as compared with individuals who remained. Cognitive functioning differences may contribute to selection bias in longitudinal ageing studies, impeding accurate conclusions in developmental research. In addition, examining the functional capabilities of attriters may be valuable for determining whether attriters experience functional limitations requiring healthcare attention.

Comparing Acute Responses Between Single Session Circuit Training and Fireground Suppression Tasks.

ABSTRACT: Loewen, B, Melton, B, Maupin, D, and Ryan, G. Comparing acute responses between single session circuit training and fireground suppression tasks. J Strength Cond Res 37(8): 1667-1678, 2023-The purpose of this study was to compare the cardio-metabolic and perceived demands of task-specific circuit training to fireground suppression tasks (FST). Twenty-three career, structural firefighters performed three separate testing days (i.e., FST, CT, and CTW). FST consisted of performing seven common occupational tasks in full gear (∼22.5kg). The weighted (CTW: 18.9kg vest) and unweighted (CT) circuit utilized seven exercises designed to mimic the FST's. Measurements included relative heart rate (%HRmax), post-training blood lactate (Lapost), change in countermovement jump height (▵CMJ), change in dominant and non-dominant handgrip strength (▵DHG and ▵NDHG), total training time, rating of perceived exertion (RPE), and job-specific rating of relevance. A repeated measure analysis of variance (ANOVA), with Bonferroni post-hoc, was performed for each variable, excluding RPE and rating of relevance. Friedman's ANOVA was used to assess differences in RPE and rating of relevance, with Wilcoxen Signed Rank tests follow-up. Significant mean differences were found in %HRmax between CT and FST (∼8.6%, p < 0.01, d = 1.12) and CTW and FST (∼5.3%, p < 0.01, d = 0.75), ▵CMJ between CT and FST (p < 0.01, d = 1.35) and CTW and FST (p < 0.01, d = 1.09), ▵NDHG between CTW and FST (p = 0.01, d = 0.79), training time between CT and FST (p < 0.01, d = 1.00) and CTW and FST (p < 0.01, d = 1.81), and rating of relevance between CT and FST (PSdep = 0.67). In conclusion, CT and CTW were able to elicit similar metabolic and perceived demands as FST, while producing a lower cardiovascular response. Therefore, while circuit training may be a beneficial training tool for firefighters, it cannot replicate FST.

Fitness Profiles in Elite Tactical Units: A Critical Review.

Elite tactical units complete a variety of demanding tasks and a high level of fitness is required by this population to perform their occupational tasks optimally. The aim of this critical review was to identify and synthesize key findings of studies that have investigated the fitness profiles of elite tactical units. Included studies were critically appraised, using the Downs and Black checklist, and a level of evidence was determined. Relevant data were extracted, tabulated, and synthesized. Fourteen studies were included for review and ranged in percentage quality scores from 46% to 66% with a mean of 57.5%. Moderate interrater agreement (κ = 0.496) existed between raters. A variety of fitness measures were used across various domains of fitness. The most common measures were in the areas of anthropometric measures, strength, power, and aerobic capacity. However, there was high variety in the measures and their protocols. Though fitness appears to be a critical part of research and practice in tactical populations, currently there is no standardized measure or result for this population. Further research in fitness profiling should be completed using standardized outcome measures which cover the spectrum of the fitness demands for this population.