Reliability and Validity of the HBSC Physical Activity Questionnaire in Japanese Adolescents

<b>Background/Objectives</b>: International physical activity (PA) questionnaires require a reliability and validity assessment in many countries to understand cross-cultural differences accurately. The current study examined the reliability and validity of the Japanese version of the WHO Health Behaviour in School-aged Children PA (HBSC-J) survey in adolescent students in Japan. <b>Methods</b>: The participants were 215 Japanese high school students. The HBSC-J was administered twice to measure reliability. The PA in the last week evaluated using the HBSC-J was compared with the PA evaluated using a triaxial accelerometer to measure the concurrent validity. <b>Results</b>: The intraclass correlation coefficients (ICCs) for reliability were 0.74 for the number of days, with 60 min/day or more of moderate-to-vigorous PA (MVPA). For the days with an MVPA of 60 min/day or more, ICCs were lower for girls (0.63 [0.49-0.74]) than boys (0.82 [0.75-0.87]). Positive correlations were observed between the accelerometry MVPA and the number of days, with at least 60 min/day of MVPA (r = 0.44). <b>Conclusions</b>: The HBSC-J questionnaire should be acceptable for evaluating MVPA in Japanese adolescents, with a reasonable reliability and validity.