Using accelerometer feedback to identify walking destinations, activity overestimates, and stealth exercise in obese and nonobese individuals.

BACKGROUND: Accelerometer output feedback might enable assessment of recall biases for moderate bouts by obese and nonobese individuals; accelerometry might also help residents recall destinations for moderate-intensity walking bouts.
METHODS: Adult residents' 1-week accelerometer-measured physical activity and obesity status were measured before and after a new rail stop opened (n = 51 Time 1; n = 47 Time 2). Participants recalled the week's walking bouts, described them as brisk (moderate) or not, and reported a rail stop destination or not.
RESULTS: At the end of the week, we provided accelerometry output to residents as a prompt. Recall of activity intensity was accurate for about 60% of bouts. Nonobese participants had more moderate bouts and more "stealth exercise" --moderate bouts recalled as not brisk--than did obese individuals. Obese participants had more overestimates--recalling light bouts as brisk walks--than did nonobese individuals. Compared with unprompted recall, accelerometry-prompted recalls allowed residents to describe where significantly more moderate bouts of activity occurred.
CONCLUSION: Coupling accelerometry feedback with self-report improves research by measuring the duration, intensity, and destination of walking bouts. Recall errors and different patterns of errors by obese and nonobese individuals underscore the importance of validation by accelerometry.