Validation and invariance testing of the English Short Physical activity enjoyment scale

Enjoyment is recognized as a determinant of physical activity habits. The enjoyment of engaging in physical activity can be measured with the Physical Activity Enjoyment Scale (PACES). Later versions of this scale have been shortened to capture the component of subjective feeling, which has been validated using German-speaking samples. The aim of this study was to examine internal consistency, factorial validity, criterion-related validity, test-retest reliability, and measurement invariance (across gender and languages) in an English-speaking population. Data on physical activity enjoyment and self-reported physical activity were collected through an online survey with a test-retest design (n = 276,189 female, M = 42.55, SD = 16.81 years) conducted from September 2023 to December 2023. In addition, a German-speaking sample (n = 1017, 497 female, M = 29.77, SD = 13.54 years) was analyzed to assess measurement invariance with respect to language. McDonald's omega at time 1 was ω = 0.95. The confirmatory factor analysis supports the assumption of the unidimensional structure of PACES-S (χ2 = 19.8, df = 2, p < 0.05; CFI = 0.984; RMSEA = 0.180, 90% CI [0.113-0.256]), as the model fit can be estimated as good in view of the CFI value, while the sensitivity of the χ2 test is very high and the RMSEA may underestimate the model fit. Although the RMSEA value is higher than the conventional threshold, the small number of degrees of freedom may have a significant impact on this indicator. The criterion-related validity for light physical activity was r(107) = 0.26 (p < 0.05). The retest reliability was r(199) = 0.69 (p < 0.05). Further, the results supported measurement invariance across gender and partial measurement invariance across languages. Overall, the English PACES-S demonstrated good psychometric properties specifically for light intensity of physical activity, and can serve as an economical instrument to assess physical activity enjoyment.