Why are some people more fit than others? Correlates and determinants of cardiorespiratory fitness in adults: protocol for a systematic review

Abstract

BackgroundCardiorespiratory fitness (CRF) is a physical condition that is now well established as a predictor of numerous adverse health outcomes, independent of physical activity levels. In order to be able to improve CRF at the population level and to develop effective interventions and public health programmes, it is important to understand why some people are more fit than others. Therefore, the primary aim of the systematic review described in this protocol is to examine individual and interpersonal factors that are correlated with or determine CRF among adults.MethodsThe review will focus on quantitative studies that investigate any personal and interpersonal correlates and/or determinants of objectively measured CRF among the general, non-symptomatic, non-institutionalized adult population (aged 18–65 years) worldwide. The databases MEDLINE, Embase, and Cochrane Library will be searched to identify all relevant published journal articles, and Google Scholar and Scopus will be searched for grey literature. Studies where CRF is not an outcome variable and experimental studies where participants specifically receive a fitness intervention that increases CRF will be excluded. For each study, data extracted will include, among other variables, study characteristics, methodology for selecting participants into the study as well as the participants’ demographic characteristics, types of correlates and determinants of CRF investigated and their measurement methods, the objective measure of CRF used and its measurement method and validity, and the main reported results on the association between the correlates or determinants and CRF. In addition, observational studies will be assessed for methodological quality and risk of bias using a customized version of the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies by the National Heart, Lung, and Blood Institute. Experimental studies will be assessed using the 27-item Downs and Black “Checklist for Measuring Study Quality”. The final results will be presented as a narrative synthesis of the main findings of all included studies.DiscussionBy consolidating and synthesizing the current research on possible individual and interpersonal correlates and determinants of CRF among adults worldwide, we aim to aid future public health actions, as well as identify gaps in our full understanding of what influences CRF.Systematic review registrationPROSPERO CRD42017055456.Electronic supplementary materialThe online version of this article (doi:10.1186/s13643-017-0497-4) contains supplementary material, which is available to authorized users.

Socioeconomic Correlates and Determinants of Cardiorespiratory Fitness in the General Adult Population: a Systematic Review and Meta-Analysis

“…It is a subset of a broader systematic review that was registered at International Prospective Register of Systematic Reviews (PROSPERO): CRD42017055456. The systematic review protocol was published elsewhere in detail [ 28 ]. Instead of all determinants and correlates of CRF, the current review focuses on the association between SES and CRF.…”

Individual and interpersonal correlates of cardiorespiratory fitness in adults – Findings from the German Health Interview and Examination Survey

“…performed in order to identify potential individual and socioeconomic correlates of CRF 8,14,16 . Potential interpersonal correlates of CRF were derived from evidence regarding the association of these factors and PA 12,27,28 .…”

“…Interpersonal factors. Social support was assessed using the Oslo Three-Item Social Support Scale (OSS-3) 35 and classified as poor (3)(4)(5)(6)(7)(8), moderate (9-11), and strong (12)(13)(14) social support. Marital status was grouped as single, married (while living together), and separated/divorced/widowed.…”

Low energy availability in male athletes: A systematic review of incidence, associations, and effects

“…Quality assessment procedures were applied to both the cross‐sectional and randomized control trials, respectively. All of the seven cross‐sectional studies achieved >7 out of 13, categorizing them as medium quality . None of the cross‐sectional studies justified the choice in sample size or measured exposures of interest prior to outcome measure.…”

“…Articles using cohort and cross‐sectional study designs were quality assessed using the NIH Quality Assessment Tool for observational cohort, and cross‐sectional studies' randomized control trials were evaluated for quality using the Physiotherapy Evidence Database (PEDro) scale . The cross‐sectional and cohort studies extracted were evaluated and categorized into three categories based on the eligibility criteria: low, medium, or high . All studies were included, with limitations discussed for those that rated low in quality.…”