Grimes L, et al. - In this prospective, observational, pilot study of 35 frail individuals ≥ 65 years awaiting major surgery referred to a multidisciplinary preoperative clinic at which they received a routine intervention directed at enhancing their physical activity (PA), experts used wrist-worn accelerometers (Axivity AX3) to build normative PA and acceptability data for the high-risk old preoperative population, evaluated whether PA could be altered by a prehabilitation intervention as part of routine care, estimated any relationship between accelerometer-measured PA and self-reported PA and evaluated the acceptability of wearing wrist-worn accelerometers in this population. To this population, accelerometery was concluded as acceptable and it raises in PA levels measured after an unoptimized routine clinical intervention which designates that health behavioral modification interventions could be prosperous during the preoperative period. Moreover, to create and confirm interventions for enhancing PA in this setting, accelerometers may, hence, be a beneficial tool.