title: Physical activity in non-frail and frail older adults.
abstract: BACKGROUND
  Physical activity (PA) is important for healthy ageing. Better insight into objectively measured PA levels in older adults is needed, since most previous studies employed self-report measures for PA assessment, which are associated with overestimation of PA.
  
  
  OBJECTIVE
  This study aimed to provide insight in objectively measured indoor and outdoor PA of older adults, and in PA differences by frailty levels.
  
  
  METHODS
  Data were collected among non-frail (N = 74) and frail (N = 10) subjects, aged 65 to 89 years. PA, measured for seven days with accelerometers and GPS-devices, was categorized into three levels of intensity (sedentary, light, and moderate-to-vigorous PA).
  
  
  RESULTS
  Older adults spent most time in sedentary and light PA. Subjects spent 84.7%, 15.1% and 0.2% per day in sedentary, light and moderate-to-vigorous PA respectively. On average, older adults spent 9.8 (SD 23.7) minutes per week in moderate-to-vigorous activity, and 747.0 (SD 389.6) minutes per week in light activity. None of the subjects met the WHO recommendations of 150 weekly minutes of moderate-to-vigorous PA. Age-, sex- and health status-adjusted results revealed no differences in PA between non-frail and frail older adults. Subjects spent significantly more sedentary time at home, than not at home. Non-frail subjects spent significantly more time not at home during moderate-to-vigorous activities, than at home.
  
  
  CONCLUSIONS
  Objective assessment of PA in older adults revealed that most PA was of light intensity, and time spent in moderate-to-vigorous PA was very low. None of the older adults met the World Health Organization recommendations for PA. These levels of MVPA are much lower than generally reported based on self-reported PA. Future studies should employ objective methods, and age specific thresholds for healthy PA levels in older adults are needed. These results emphasize the need for effective strategies for healthy PA levels for the growing proportion of older adults.
authors.affiliation: Department of Urban Environment and Safety, TNO, Utrecht, The Netherlands; Human geography and Planning, Utrecht University, Utrecht, The Netherlands.
authors.forename: F Marijke
authors.initials: FM
authors.lastname: Jansen
authors.affiliation: Department of Public Health, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Rick G
authors.initials: RG
authors.lastname: Prins
authors.affiliation: Department of Public Health, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Astrid
authors.initials: A
authors.lastname: Etman
authors.affiliation: Department of Public and Occupational Health, EMGO Institute for Health and Care Research, VU University Medical Center Amsterdam, Amsterdam, The Netherlands.
authors.forename: Hidde P
authors.initials: HP
authors.lastname: van der Ploeg
authors.affiliation: Department of Healthy Living, TNO, Leiden, The Netherlands; Healthy Lifestyle in a Supporting Environment, The Hague University of Applied Sciences, The Hague, The Netherlands.
authors.forename: Sanne I
authors.initials: SI
authors.lastname: de Vries
authors.affiliation: Department of Public Health, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: van Lenthe
authors.affiliation: Department of Urban Environment and Safety, TNO, Utrecht, The Netherlands.
authors.forename: Frank H
authors.initials: FH
authors.lastname: Pierik
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D016330:Frail Elderly; D015577:Geriatric Assessment; D006304:Health Status; D006801:Humans; D008297:Male; D009043:Motor Activity; D062486:Public Health Surveillance; D013997:Time Factors