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The world’s population is aging rapidly, as both life expectancy and the proportion of older people are increasing. This aging of the population is an indicator of improved health conditions and should be considered as a success story. However, it is also one of the main challenges that the world is facing because there is a growing need to prevent age-associated declines and diseases such as cardiovascular disease, diabetes, dementia, and osteoporosis. Physicalnbsp;(PA) has been identified as a major public health priority because it can help to prevent, or even reverse age-associated declines and losses of many physical and psychological variables. The present doctoral thesis, entitled ‘Objective assessment and promotion of PA in older adults living in residential care facilities’ focuses on three interrelated aims: assessment (CHAPTER 1), screening (CHAPTER 2), and intervention (CHAPTER 3). The first aim was to investigate the validity of two motion sensors in institutionalized older adults (Paper 1 and Paper 2). Accurate quantification of both PA and sedentary behavior isnbsp;for screening, goal setting, and program evaluation. The second aim was to examine the link between muscle strength and functional performance, and to identify functionally relevant cut-off values for knee extension strength in older adults (Paper 3). It is important to determine physical characteristics related to functional deterioration, as this will eventually lead to a loss of independence and institutionalization, and an increase in healthcare costs. Finally, thenbsp;aim was to examine the short- andnbsp;effects on PA, functional performance and muscle strength of a 10-week cycle ergometer intervention in assisted living facilities (Paper 4). PA promotion in older adults is important because a large proportion of the older population is not regularly involved in PA. Paper 1 examined the accuracy of a hip-worn and ankle-worn piezoelectric pedometer and the multisensornbsp;Mini (SWMini) in measuring steps during daily life activities in nursing home residents (N=68; mean age=86 years). The results revealed that the multisensor and hip- and ankle-worn pedometer significantly underestimated step counts, although measurement accuracy was higher when the pedometer was worn at the ankle. Moreover, pedometer accuracy improved as walking speed increased. The ankle-worn piezoelectric pedometer proved to be acceptably accurate for quantifying steps at walking speeds of ≥2.35 km/h. Next to step counts, energy expenditure (EE) is a common outcome when assessing PA in daily life. Therefore, the purpose of Paper 2 was to examine the validity of the SWMini to measure EE during rest and during the performance of daily life activities in a sample of nursing home residents (N=60; mean age=86 years). The results showed that the SWMini can be applied for describing and quantifying sitting time in institutionalized older adults because significant increases between sitting periods and daily life activity tasks were found. In addition, analyses revealed that the SWMini demonstrated good agreement with indirect calorimetry, although the device underestimated EE. Age was determined as a key factor of accuracy, suggesting that accurate age- and activity-specific algorithms should be developed. nbsp;second chapter of this doctoral thesis examined whether knee extension and handgrip strength, measured using two field tests, are good predictors ofnbsp;performance among older adults (nbsp;years). In total, 770 community-dwelling older adults, 104 older adults living in assisted living facilities and 73 nursing home residents were included in Paper 3 to cover a broad range of strength performance and functionality levels. Results revealed that both handgrip and knee extension are important predictors of functional performance in older adults. In assisted living facilities only, knee extension strength proved to be a better predictor of functional performance than handgrip strength. Early identification of persons with muscle weakness might create opportunities for developing and implementing strategies to counteract disability. Specific cut-off values for functionally relevant muscle strength for men and women respectively were set at 0.40 and 0.31 kg per kg body weight (BW) for lower body strength and at 0.43 and 0.31 kg per kg BW for upper body strength. These cut-off values should be used in clinical practice to detect and double check older adults at risk for muscle weakness, using simple field tests. The results obtained in Paper 3 contributed to the development of a PA intervention in Paper 4. In this paper, ergometer cycling was used for the promotion of PA among residents living in an assisted living facility (N=95, mean age=82 years). Ergometer cycling trains the cardio-respiratory system as well as lower body muscles. The purpose of this last paper was to evaluate the short- and long-term effectiveness of an ergometer cycling intervention, comparing 2 coaching procedures: (1) structured fitness coaching (STRUC) with permanent assistance, consisting of three weekly sessions on a cycle ergometer, and (2) autonomy-supportive coaching (AUT) based on the Self-Determination Theory, consisting of an individualized cycle ergometer program with minimal coaching contact. Especially the autonomy-component considerably differed between both intervention groups as participants in AUT had to complete the program on their own, without supervision ofnbsp;coach. The effects on adherence rate, PA, functionality and muscle strength were assessed at baseline, post-intervention (10 weeks after pre) and at follow-up (24 weeks after post). Results showed that minimal contact with a coach is sufficient to promote ergometer cycling in older adults, but training volumes are higher in bothnbsp;short- and long-term when training is strictly supervised. Contrary to our hypotheses, stimulating autonomy in this age group did not result in higher long-term adherence rates. Self-reported moderate intensity PA increased from pre tonbsp;in both intervention groups in comparison with the control group. However, only AUT showed short-term gains in daily EE. At last, older adults who exercised more frequently on the cycle ergometer showed better short-term results on functionality and muscle strength, even though improvements were small. The present doctoral thesis offers important information regarding screening of older adults at risk for functional impairment, and regarding objective assessment and promotion of PA in older adults living in residential care facilities. Researchers and practitioners can use this information for future PA recommendations and PA interventions in the old and old-old. status: published |
