How Important is the Use of a Logbook in Addition to Accelerometer to Assess the Proportion of Insufficiently Active 13-year-old Girls?

Introduction It is strongly recommended to use objective measurements for the assessment of physical activity among children and adolescents. However, as some activities such as bicycling/inline skating/scooter are incorrectly recorded by accelerometer, assisting methods are needed to obtain correct data. The aim of the study was to examine the proportion of insufficiently active girls based on data from accelerometer only compared to data from accelerometer combined with a logbook.

Method In the city of Graz and in the rural surroundings 178 13-year-old girls filled in a logbook. Of those, 125 girls wore an accelerometer (GT3X+) for at least four days. In the logbook we particularly asked about the duration of cycling/inline skating/scooter for transport per day as this is recorded with the accelerometer as light-intensity physical activity. We calculated the average minutes of at least moderate-intensity physical activity (MVPA) per day as well as the average minutes of cycling/inline skating/scooter per day of each individual. Finally, we divided the girls into insufficiently (less than 60 min of MVPA per day) and sufficiently active groups. McNemar chi-squared test was applied.

Results Cycling/inline skating/scooter for transport were performed at least once a week by 49% of the girls with a median duration of 36 min per day. Based on the accelerometer data 84% of the girls were insufficiently active. After adding the minutes of MVPA assessed by accelerometer and the minutes of cycling/inline skating/scooter derived from the logbook the proportion of insufficiently active girls was reduced statistically significantly to 53%.

Discussion In our sample of young girls the prevalence of cycling/inline skating/scooter at least once a week was almost 50%. As long as accelerometers do not appropriately measure e.g. non weight bearing physical activities such as bicycling, it is strongly recommended to additionally apply methods to capture those activities. Without taking cycling/inline skating/scooter into account, the prevalence of insufficiently active girls would have been overestimated considerably in our study. Furthermore, correct information about such activities is important to assess relationships between MVPA and active transport or for tracking of cycling/inline skating/scooter over time (Carver et al., 2011).

References Carver A, Timperio AF, Hesketh KD, Ridgers ND, Salmon JL, Crawford DA. (2011). Int J Behav Nutr Phys Act, 8, 126.