*2.2. Eligibility Criteria*

The inclusion criteria for this systematic review were the (1) age criterion: adults (19–64 years old). During this review, we faced the problem that some studies sampled adults and older adults, or adults or adolescents together. In these cases, we observed whether these studies performed stratified analyses by age groups, isolating the adult population from the rest; if so, the study was included and information concerning the adult population reported. In contrast, when the authors analysed the whole sample together, we only included the study if the age of the sample was predominantly within our study age range; (2) participants: the study population was based on a generally healthy population, who did not present any injury, physical and/or mental disabilities, irrespective of body mass index (BMI), diabetes or other cardiovascular risks (i.e., hypertension, hypercholesterolemia, lipid profiles, glucose levels, insulin sensitivity); and (3) study design: original studies or systematic reviews/meta-analysis. The original studies that were selected for the analysis of their criterion-related validity but which were also included in the selected systematic reviews were excluded; (4) language criterion: articles were only published in English or Spanish; (5) topic criterion: studies examining the criterion-related validity of

the field-based fitness test. Studies examining the relationship between field-based fitness tests were excluded. Likewise, studies that analysed the criterion-related validity of tests designed for exclusive use in sports or clinical settings were not included.

Two authors (J.C.P. and J.R.F.S.) independently assessed the titles and abstracts of the articles retrieved by the search strategy for eligibility. Then, the full texts of the selected articles were acquired, and the same two researchers independently screened them to determine whether to include the article based on the inclusion criteria. When no consensus was reached between both researchers, a third research (N.M.J.) made the final decision with regard to inclusion. Reasons for the exclusion of identified articles were recorded.
