The impact of body-size adjustment on the interpretation of physical fitness test outcomes in physical education students

Background and Study Aim. Field-based physical fitness tests are widely used in the assessment of physical education students. However, test interpretation is often based on absolute outcomes that do not account for differences in body size, potentially influencing the evaluation of sex- and country-related differences. The aim of this study was to determine whether the interpretation of selected physical fitness test outcomes differs when absolute results and simple body-size-adjusted indicators are applied. Materials and Methods. A cross-sectional study was conducted among 515 undergraduate physical education students from Poland (n = 258) and Romania (n = 257). Physical fitness was assessed using three Eurofit tests: plate tapping, sit-ups, and standing long jump. Test outcomes were analyzed using both absolute values and simple body-size-adjusted indicators. Sex- and country-related differences were examined using two-way analysis of variance. Results. Analyses based on absolute outcomes revealed significant sex- and country-related differences across all tests, with a particularly large sex effect observed in the standing long jump. After adjustment for body size, group differences were substantially reduced in tests requiring body mass displacement, and sex-related differences in the standing long jump were no longer statistically significant. In contrast, the results of the plate tapping test remained unchanged regardless of the method used to express performance outcomes. Conclusions. The findings indicate that the interpretation of physical fitness test results in physical education students may vary depending on whether absolute outcomes or simple body-size-adjusted indicators are used. The applied ratio-based adjustments substantially altered the pattern of sex- and country-related differences in tests involving body mass displacement, whereas they had little influence on outcomes primarily reflecting movement speed and coordination. These findings suggest that simple body-size-adjusted indicators may influence the interpretation of physical fitness outcomes in educational and comparative settings.