Physical activity quantified by questionnaire and accelerometry in schoolchildren. A comparison

Introduction: Questionnaires have long been the tool of choice for the measurement of physical activity in large population groups, however, they depend on the accuracy with which they are answered. Accelerometers, on the other hand, can directly measure physical activity, eliminate subjectivity and, allow comparisons with instruments such as questionnaires.

Objective: Establish the correlation level of the Four by one-day physical activity questionnaire (FOPAQ) with the ActiGraph wGT3x-BT accelerometer based on the quantification of the daily physical activity of school children aged 6 to 11 years.

Method: 107 schoolchildren were evaluated with the FOPAQ and the ActiGraph wGT3x-BT accelerometer from thursday to sunday. For the correlation analyzes, only 43 children were chosen who correctly answered the FOPAQ. The time spent in four levels of activity intensity was obtained: sedentary, light, moderate and vigorous, for both methods. Pearson and Spearman correlations were performed, in addition to a t-Student and Wilcoxon test of each of the variables between the FOPAQ and the accelerometer of the four days measured.

Results: The Spearman correlations ranged from -0,103 to 0,077 and the Pearson correlations ranged from -0,058 to 0,014. The FOPAQ overestimated the sedentary and vigorous activity time as well as underestimated the light and moderate activity time.