This study aimed to determine the optimal accelerometer wear-site specific cut-points for discrimination of sedentary time, light physical activity and moderate-to-vigorous physical activity in older adults. Twenty-three adults (14 females) aged 55 to 77 years wore a GENEActiv accelerometer on their non-dominant wrist, dominant wrist, waist and dominant ankle whilst undertaking eight, five-minute bouts of activity: lay supine, seated reading, slow walking, medium walking, fast walking, folding laundry, sweeping and stationary cycling. VO2 was assessed concurrently using indirect calorimetry. Receiver-operating-characteristic (ROC) analyses were used to derive wear-site specific cut-points for classifying intensity. Indirect calorimetry indicated that being lay supine and seated reading were classified as sedentary (<1.5 METs), laundry as light (1.51-2.99 METs) and sweeping, slow, medium and fast walking and cycling all classified as moderate intensity (>3 METs). Areas under ROC curves (AUC) indicated that classification of sedentary activity was good for the non-dominant wrist and excellent for all other wear sites. Classification of moderate-to-vigorous physical activity (MVPA) was excellent for the waist and ankle, good for the waist and poor for the dominant and non-dominant wrists. Overall, the ankle location performed better than other locations. Ankle-worn accelerometry appears to provide the most suitable wear-site to discriminate between sedentary time and MVPA in older adults.
- Indirect Calorimetry
- Energy Expenditure
- Sedentary Behaviour
Duncan, M., Rowlands, A., Lawson, C., Leddington Wright, S., Hill, M., Morris, M., ... Tallis, J. (2019). Using accelerometery to classify physical activity intensity in older adults: what is the optimal wear-site? European Journal of Sport Science, (In-press), (In-press). https://doi.org/10.1080/17461391.2019.1694078