*Review* **Criterion-Related Validity of Field-Based Fitness Tests in Adults: A Systematic Review**

**Jose Castro-Piñero 1,2, Nuria Marin-Jimenez 1,2,\*, Jorge R. Fernandez-Santos 1,2, Fatima Martin-Acosta 1,2, Victor Segura-Jimenez 1,2, Rocio Izquierdo-Gomez 1,2, Jonatan R. Ruiz <sup>3</sup> and Magdalena Cuenca-Garcia 1,2**


**Abstract:** We comprehensively assessed the criterion-related validity of existing field-based fitness tests used to indicate adult health (19–64 years, with no known pathologies). The medical electronic databases MEDLINE (via PubMed) and Web of Science (all databases) were screened for studies published up to July 2020. Each original study's methodological quality was classified as high, low and very low, according to the number of participants, the description of the study population, statistical analysis and systematic reviews which were appraised via the AMSTAR rating scale. Three evidence levels were constructed (strong, moderate and limited evidence) according to the number of studies and the consistency of the findings. We identified 101 original studies (50 of high quality) and five systematic reviews examining the criterion-related validity of field-based fitness tests in adults. Strong evidence indicated that the 20 m shuttle run, 1.5-mile, 12 min run/walk, YMCA step, 2 km walk and 6 min walk test are valid for estimating cardiorespiratory fitness; the handgrip strength test is valid for assessing hand maximal isometric strength; and the Biering–Sørensen test to evaluate the endurance strength of hip and back muscles; however, the sit-and reach test, and its different versions, and the toe-to-touch test are not valid for assessing hamstring and lower back flexibility. We found moderate evidence supporting that the 20 m square shuttle run test is a valid test for estimating cardiorespiratory fitness. Other field-based fitness tests presented limited evidence, mainly due to few studies. We developed an evidence-based proposal of the most valid field-based fitness tests in healthy adults aged 19–64 years old.

**Keywords:** cardiorespiratory fitness; muscular strength; motor fitness and flexibility; validation; fitness testing; adulthood
