Measuring physical activity in field studies: Comparison of a questionnaire, 24h recall and accelerometer

In a field setting, we compared a physical activity questionnaire (SQUASH), a 24-hour recall measure (Physical Activity Scale; PAS), and an accelerometer to: (1) quantify the amount of time spent in light, moderate, and vigorous physical activity; (2) calculate activity scores; and (3) categorize participants by physical activity tertiles. For 7 consecutive days, 103 participants (61% males, 39% females; mean age 36.8 years, mean body mass index 26.6 kg.m(-2)) wore an accelerometer and completed the PAS. Immediately before these 7 days, the participants completed the SQUASH and underwent anthropometric measurements (weight and height). Time spent in light (= 6 METs) activity was calculated. Significant correlations were observed between the PAS and accelerometer in the population as a whole (r = 0.66, P