Wearable multisensor and total energy expenditure estimation in young, adult and institutionalized elderly individuals : validation and practical recommendation

Older institutionalized individuals with reduced residual abilities are going to growth in number in the next years. Monitoring the daily energy expenditure may allow a correct dietary intake and an effective physical activity program, thus improving their life quality. Wearable multisensors (WMS) have been developed to estimate energy expenditure (EE), but, if not calibrated, their accuracy may become questionable. This study was aimed at evaluating WMS accuracy in EE estimation in institutionalized elderly people where individual calibration is difficult to perform. Methods: Twenty-three participants (age 48 ± 27 years; body mass 66.6 ± 12.7 kg; stature 1.69 ± 0.11 m; mean ± SD) were divided in young (YNG, <30 years; n = 9), adult (AD, 30–60 years, n = 7), and institutionalized elderly (ELD, >60 years; n = 7) individuals. EE at two different exercise intensities during cycling with the upper (UA) or lower limbs (LL) and walking was measured by indirect calorimetry (IC) and estimated by WMS. Results: Estimated EE was always significantly lower than in IC in YNG and AD (P < 0.05). WMS underestimated EE in all conditions and the error increased with physical activity intensity. In YNG and ELD the correlation coefficient between measured and estimated EE improved during walking (R = 0.61 and R = 0.34 in YNG and ELD, respectively). In AD the best correlation occurred during LL (R = 0.78). Conclusions: Without individual calibration, WMS underestimated EE measured by IC during all physical activities, with the lower correlation coefficient in institutionalized individuals. An individual calibration of WMS seems to be mandatory to obtain accurate estimations of EE, especially in institutionalized elderly people.