摘要：Background: Insufficient physical activity is considered a major threat to future public health as many children and adolescents do not engage in the recommended amount of physical activity (PA), despite the well-documented health benefits. The evaluation of ongoing efforts as well as future intervention strategies, however, requires an accurate assessment of PA. Aim: The present study, therefore, examined differences between objectively and subjectively determined PA in 36 Austrian adolescents (52.8% male; 13.5 ± 0.5 years of age). Methods: Time spent in moderate-to-vigorous PA (MVPA) and time spent sedentary was assessed with a wrist-worn accelerometer (GENEActive) that was worn for 7 consecutive days. Self-reported sleep duration was subtracted from total sedentary time in order to obtain sedentary time during waking hours. Participants also completed the short version of the International PA questionnaire (IPAQ) at the end of the objective measurement, which assesses time spent in MVPA and sitting time during the previous week. Results: Objective and subjective data showed that adolescents spent the majority of their time sitting or in sedentary pursuits. Self-reported MVPA was more than double the amount of the objectively determined time spent in MVPA (p p Conclusions: These results highlight the difficulty to accurately determine PA via questionnaire, which may be attributed to irregular PA patterns in youth. Accordingly, subjective measurements may need to be combined with objective methods in order to enhance the accuracy of PA assessments. The low levels of objectively determined PA, particularly in girls, further emphasize the need for continued efforts to ensure an adequate amount of PA in youth.
