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Guiding Research and Practice: A Conceptual Model for Aerobic Exercise Training in Alzheimer's Disease
Abstract
Alzheimer's disease is a global, epidemic problem affecting mainly older adults with tremendous social and financial burdens. Older adults with Alzheimer's disease showed reduced physical activity and cognitive changes that are probably amenable to aerobic exercise training. The purpose of this paper is to develop a conceptual model to guide future aerobic exercise research and practice by synthesizing the current state of the science on aerobic exercise training in older adults with AD. The literature review found 12 qualified studies that met the eligibility criteria for inclusion in this review and revealed six constructs (aerobic exercise training, physical fitness, physical performance, activities of daily living limitations, cognition, and psychological and behavioral symptoms), which composed the Functional Impact of aerobic exercise Training in Alzheimer's disease (FIT-AD) model. The state of science on each construct in older adults with Alzheimer's disease is reviewed and summarized. The emerging evidence suggests that aerobic exercise training might positively impacts all five other constructs. The implications of the FIT-AD model for future research and practice are discussed highlighted.
... Engaging in routine physical activity could reduce the risk of developing the disease [4][5][6][7][8][9][10][11]. For individuals with Alzheimer's disease, physical activity may help to mitigate and even improve some of the mental [4,[12][13][14][15][16][17][18][19][20][21][22][23][24][25] and physical [12,19,20,22,24,[26][27][28][29][30] symptoms. Moreover, a recent population-based analysis of seven potentially modifiable Alzheimer's disease risk factors revealed that the largest proportion of disease cases in the United Kingdom, United States and Europe could be attributed to physical inactivity. ...
... Engaging in routine physical activity could reduce the risk of developing the disease [4][5][6][7][8][9][10][11]. For individuals with Alzheimer's disease, physical activity may help to mitigate and even improve some of the mental [4,[12][13][14][15][16][17][18][19][20][21][22][23][24][25] and physical [12,19,20,22,24,[26][27][28][29][30] symptoms. Moreover, a recent population-based analysis of seven potentially modifiable Alzheimer's disease risk factors revealed that the largest proportion of disease cases in the United Kingdom, United States and Europe could be attributed to physical inactivity. ...
... These statements were constructed by the lead author. The first statement was a summary of conclusions drawn in the reviews shown in Table 3, particularly those cited by Yu [24]. Yu's conclusions were considered an appropriate starting point because they captured a broad range of outcomes. ...
Background
The impending public health impact of Alzheimer’s disease is tremendous. Physical activity is a promising intervention for preventing and managing Alzheimer’s disease. However, there is a lack of evidence-based public health messaging to support this position. This paper describes the application of the Appraisal of Guidelines Research and Evaluation II (AGREE-II) principles to formulate an evidence-based message to promote physical activity for the purposes of preventing and managing Alzheimer’s disease. MethodsA messaging statement was developed using the AGREE-II instrument as guidance. Methods included (a) conducting a systematic review of reviews summarizing research on physical activity to prevent and manage Alzheimer’s disease, and (b) engaging stakeholders to deliberate the evidence and formulate the messaging statement. ResultsThe evidence base consisted of seven systematic reviews focused on Alzheimer’s disease prevention and 20 reviews focused on symptom management. Virtually all of the reviews of symptom management conflated patients with Alzheimer’s disease and patients with other dementias, and this limitation was reflected in the second part of the messaging statement. After deliberating the evidence base, an expert panel achieved consensus on the following statement: “Regular participation in physical activity is associated with a reduced risk of developing Alzheimer’s disease. Among older adults with Alzheimer’s disease and other dementias, regular physical activity can improve performance of activities of daily living and mobility, and may improve general cognition and balance.” The statement was rated favourably by a sample of older adults and physicians who treat Alzheimer’s disease patients in terms of its appropriateness, utility, and clarity. Conclusion
Public health and other organizations that promote physical activity, health and well-being to older adults are encouraged to use the evidence-based statement in their programs and resources. Researchers, clinicians, people with Alzheimer’s disease and caregivers are encouraged to adopt the messaging statement and the recommendations in the companion informational resource.
... Néanmoins, chez les patients Alzheimer, la plupart des études s'intéressant à l'APRA n'impose pas spécifiquement une intensité d'exercice (voir pour revue [40]). Toutefois, ces interventions rapportent des effets positifs (Tableau 1) sur les symptômes dépressifs, l'humeur [40], le niveau global de cognition, les activités de vie quotidienne [40,41] et les performances physiques [40][41][42][43]. ...
... Néanmoins, chez les patients Alzheimer, la plupart des études s'intéressant à l'APRA n'impose pas spécifiquement une intensité d'exercice (voir pour revue [40]). Toutefois, ces interventions rapportent des effets positifs (Tableau 1) sur les symptômes dépressifs, l'humeur [40], le niveau global de cognition, les activités de vie quotidienne [40,41] et les performances physiques [40][41][42][43]. Seulement deux études chez les patients Alzheimer ont contrôlé spécifiquement l'intensité d'exercice pour stimuler de manière intense la fonction cardiorespiratoire [44,45] (c.-à-d., 70 % de la FC maximale et 70 % de la FC de réserve). ...
... Néanmoins, chez les patients Alzheimer, la plupart des études s'intéressant à l'APRA n'impose pas spécifiquement une intensité d'exercice (voir pour revue [40]). Toutefois, ces interventions rapportent des effets positifs (Tableau 1) sur les symptômes dépressifs, l'humeur [40], le niveau global de cognition, les activités de vie quotidienne [40,41] et les performances physiques [40][41][42][43]. Seulement deux études chez les patients Alzheimer ont contrôlé spécifiquement l'intensité d'exercice pour stimuler de manière intense la fonction cardiorespiratoire [44,45] (c.-à-d., 70 % de la FC maximale et 70 % de la FC de réserve). ...
Aims
This article summarizes the literature on some of the biological mechanisms involved in Alzheimer disease and their evolution in the context of non-pharmacological interventions.
Actuality
Regular aerobic physical activity and enriched environment are two methods derived from the metabolic hypothesis and the cognitive enrichment hypothesis respectively. Their effects on aerobic fitness, cardiorespiratory function, brain structure and cognition are clearly established in the aging process in humans and animals. In the field of Alzheimer's disease, these methods might halt mitochondrial, amyloidogenic and tau pathophysiological development.
Perspectives
In elderly patients, the use of exergames (active video games) develops in order to make physicals activities more attractive. These new technologies, with high potential, would propose simultaneously aerobic activity in an enriched environment. Intervention research on the feasibility and the effects of these exergames for Alzheimer patients may be a way forward.
Conclusion
We propose to use serious (exer)games to stimulate Alzheimer patients. These serious games, being specifically developed for Alzheimer patients, would be to integrate high intensity aerobic activity and enriched environment into a ludic and accessible therapy.
... n = 23) in older adults with AD (Landi, Russo, & Bernabei, 2004). While the above findings indicate that aerobic exercise might indeed be a potential intervention for AD, few studies have evaluated the efficacy of a well-designed and delivered aerobic exercise intervention in a clearly characterized AD sample (Forbes et al., 2008;Yu, 2011). With few exceptions (Cyarto et al., 2010), the ADAS-Cog has not been used in exercise studies in AD. ...
... Our cognitive finding is consistent with the results from other aerobic exercise studies (Arkin, 2003;Kemoun et al., 2010;Rolland et al., 2007;Williams & Tappen, 2007;Williams & Tappen, 2008). Adherence in this study was toward the high end of the reported 17% to 90% adherence; however, it is often unclear how the adherence was determined in those studies that used low exercise doses and lacked clear description of the prescribed exercise doses (Yu, 2011). ...
... Those problems are accentuated for older adults with AD who likely require supervised exercise given their impaired judgment, decision-making, and cognition. Currently, most exercise studies in AD have been conducted in nursing home settings with not well-characterized AD samples (Forbes et al., 2008;Heyn, 2003;Yu, 2011). This study was able to enroll a wellcharacterized AD sample (confirmed AD diagnosis and staging using MMSE and CDR) and successfully delivered the intervention in community-based exercise settings. ...
Little is known about how aerobic exercise affects Alzheimer's disease (AD). The purpose of this pilot study was to test the impact of 6-month cycling on AD symptoms in community-dwelling older adults with mild-to-moderate AD, using a single-group, repeated-measures design (n = 26). AD symptoms were measured with the AD Assessment Scale-Cognitive (ADAS-Cog), Disability in AD (DAD), and Neuropsychiatric Inventory-Caregiver (NPI-Q) scales at baseline, 3 and 6 months. Data were analyzed using mixed linear models. The ADAS-Cog, DAD, and NPI-Q severity scores remained unchanged over the 6-month period, while caregiver distress decreased 40% (p < .05). We conclude that aerobic exercise may reduce AD symptoms and appears effective in decreasing caregiver distress. Further randomized controlled trials are needed to examine the effects of aerobic exercise in AD.
... Nonetheless, there are few aerobic exercise studies in older adults with AD (Yu, 2011). They often had small sample sizes that limit the generalizability of the results. ...
... They often had small sample sizes that limit the generalizability of the results. Few studies measured change in global cognition with mixed results, and no studies have ever measured executive function (Yu, 2011). Older adults with AD improved global cognition measured by the Mini-Mental State Examination (MMSE) from 16.3 at baseline to 19.8 posttraining (p < .001) ...
... No differences in the Boston Naming Test and Hopkins Verbal Learning Test scores were found between exercisers whose caregivers provided comprehensive exercises daily for 12 weeks at home and nonexercisers (n = 27; Steinberg, Leoutsakos, Podewils, & Lyketsos, 2009). The discrepancy in findings is largely attributable to prevailing methodological issues in existent studies, for example, low intensity and duration of aerobic exercise that may not be sufficient for generating cognitive benefits, inattention to differential sensitivity of various cognitive domains to aerobic exercise, and lack of comprehensive measures of cognition (Yu, 2011). The purpose of this pilot study was to examine the effect of 6-month aerobic exercise on the change in executive function, global cognition, QOL, and depression from baseline to month 3 and 6 in communitydwelling older adults with mild to moderate AD. ...
Aerobic exercise is a promising behavioral therapy for Alzheimer's disease (AD), yet few studies have investigated the effect of aerobic exercise on cognition in AD. The purpose of this pilot study was to examine the effect of 6-month aerobic exercise on the change in executive function, global cognition, quality of life (QOL), and depression in community-dwelling older adults with mild to moderate AD. A single group, repeated measures design with outcomes measured at baseline, 3 months, and 6 months was used. Results show that there were no significant changes in any measures except for depression (p = .026). There was a trend toward improvement in executive function and QOL with moderate effect sizes (ESs) and a trend toward deterioration in global cognition with moderate to large ESs. Randomized controlled trials are needed to evaluate the therapeutic effect of aerobic exercise in older adults with AD.
... Aerobic exercise shows promise for alleviating the progression of Alzheimer's disease (AD) and its devastating social, economic, and health consequences because exercise could potentially affect AD neuropathology and improve brain plasticity (Cotman & Berchtold, 2007). However, quantifying the intensity of prescribed and delivered aerobic exercise is not commonly practiced, resulting in conflicting findings about the effects of aerobic exercise on AD symptoms (Yu, 2011). To date, only a couple of studies have used heart rate (HR) to measure the actually delivered exercise intensity (Landi, Russo, & Bernabei, 2004;Yu, Savik, Wyman, & Bronas, 2011). ...
... Recently, emerging studies have suggested that aerobic exercise shows promise for treating AD symptoms (Heyn, Abreu, & Ottenbacher, 2004). However, the findings have been conflicting, which is largely attributable to variations in the prescribed and delivered exercise doses (Forbes et al., 2008;Yu, 2011). As moderate-intensity aerobic exercise improves a variety of health outcomes and is recommended for older adults (National Institute on Aging, 2004;Vogel et al., 2009), there exists a critical need to establish valid methods to ensure the prescription and delivery of exercise intensity to advance exercise research in AD. ...
Standardized methods for prescribing and monitoring exercise intensity are needed to advance exercise research in Alzheimer's disease (AD). The purpose of this study was to evaluate the concurrent validity of a modified 1–10 Rating of Perceived Exertion (RPE) scale against heart rate (HR) in older adults with mild-to-moderate AD (N = 8, age 77–87 years). RPE and HR were assessed every 5 min during each exercise session with 3,988 data pairs. Pearson and Spearman correlations and mixed models for correlated data were used for analysis. Results show the correlation between RPE and HR and between RPE and change in HR from resting was −.11 (SE = .15) and −.31 (SE = .17), respectively. The proportions of variance explained by RPE overall, RPE within participant, and RPE within session were only 4.0, 5.3, and 6.7%, respectively. We conclude that the modified 1–10 RPE scale did not show concurrent validity to HR, with large between-individual variability.
... Together, the above findings indicate that aerobic exercise could either maintain or improve cognition in persons with AD, which are very positive findings given that progressively worsening cognition marks the course of AD. Nonetheless, aerobic exercise studies in AD are few and have been limited by such factors as small sample sizes, variable comparator groups, inconsistent cognitive measures, variable domains of cognition as a main outcome, and application of multicomponent interventions that masked the true effect of aerobic exercise [24]. The comparability of those findings is further limited due to the varied doses of aerobic exercise [24]. ...
... Nonetheless, aerobic exercise studies in AD are few and have been limited by such factors as small sample sizes, variable comparator groups, inconsistent cognitive measures, variable domains of cognition as a main outcome, and application of multicomponent interventions that masked the true effect of aerobic exercise [24]. The comparability of those findings is further limited due to the varied doses of aerobic exercise [24]. The doses rarely met the weekly 150-minute moderate-intensity level of exertion that has been recommended for older adults or the 6-month duration considered sufficient for producing cognitive gains in non-AD samples [7]. ...
Background
Alzheimer’s disease, a global public health issue, accounts for 60 to 80% of all dementias. Alzheimer’s disease primarily causes cognitive impairment and drugs have only modest short-term effects, highlighting a pressing need to develop effective interventions. Aerobic exercise holds promise for treating cognitive impairment in Alzheimer’s disease through biologically sound mechanisms. Nonetheless, aerobic exercise studies in Alzheimer’s disease are limited with mixed findings.
Methods/Design
This pilot randomized controlled trial will investigate the effects of a 6-month, individualized, moderate-intensity cycling intervention (20 to 50 minutes per session, 3 times a week) on cognition and hippocampal volume in community-dwelling older adults with mild-to-moderate Alzheimer’s disease. The specific aims are to: 1) determine the immediate effect of the cycling intervention on cognition in Alzheimer’s disease; 2) examine if the cycling intervention slows cognitive decline in Alzheimer’s disease from baseline to 12 months; and 3) assess the effect of aerobic exercise on hippocampal volume over 12 months. Ninety subjects will be randomized on a 2:1 allocation ratio to cycling or attention control (low-intensity stretching) and followed for another 6 months. Allocations will be concealed to all investigators and outcome assessors will be blinded to group assignments and previous data. Cognition will be measured by the Alzheimer’s disease Assessment Scale-Cognition at baseline before randomization and at 3, 6, 9, and 12 months. Hippocampal volume will be measured by magnetic resonance imaging at baseline and 6 and 12 months. The sample size of 90 will give 80% power to detect a 2.5-point difference in within-group changes in the Alzheimer’s disease Assessment Scale-Cognition at 6 months for the cycling group.
Discussion
Findings from this study will address the critical gap of exercise efficacy in Alzheimer’s disease and use of magnetic resonance imaging as an outcome measure in clinical trials. This study will provide a potential treatment that may increase physical function and quality of life and curb the prohibitive costs for the growing dementia population.
Trial registration
Primary registration: (NCT01954550; date of registration: 20 September 2013). Secondary registration: (NCT01954550; date of registration: 1 October 2013).
... Així mateix, hi ha evidències prometedores que els programes d'exercici físic poden tenir un impacte significatiu en la millora de la capacitat per realitzar activitats quotidianes i, possiblement, en la millora de la cognició global en les persones amb demència, encara que es recomana precaució en la interpretació d'aquests resultats 116,117 . Els seus efectes sobre els símptomes no cognitius ofereixen resultats contradictoris 116,117 . ...
... Així mateix, hi ha evidències prometedores que els programes d'exercici físic poden tenir un impacte significatiu en la millora de la capacitat per realitzar activitats quotidianes i, possiblement, en la millora de la cognició global en les persones amb demència, encara que es recomana precaució en la interpretació d'aquests resultats 116,117 . Els seus efectes sobre els símptomes no cognitius ofereixen resultats contradictoris 116,117 . ...
... This would mask the impact of the exercise intervention. This has been resolved in a single RCT study (Kemoun et al., 2010) and other non-RCTs (Palleschi et al., 1996;Hernandez et al., 2010, Yu andKolanowski, 2009;Yu et al., 2011) by implementing a target effort level for participants, this methodology should be a requirement in any exercise intervention study. ...
... MMSE, ADAS-cog) are taken that it should be alongside a more comprehensive cognitive battery. The need to improve cognitive measures used in exercise intervention studies is in line with conclusions made in a recent review (Yu, 2011). ...
Background:
Non-pharmacological interventions may have a role in both the prevention and slowing down of disease progression in Alzheimer's disease (AD). The role of exercise in disease prevention, for example, has been extensively evaluated in large epidemiological studies. Much less is known about the potential benefit of exercise in patients already diagnosed with AD. It was therefore the aim of this systematic review to assess the effectiveness of exercise in attenuating cognitive decline within AD.
Method:
A systematic review was conducted statistically accompanied by a meta-analysis. Publications between January 1991 and October 2012 were identified by searching the electronic databases PubMed, Science Direct, Web of Knowledge, and PsychINFO. Selected studies required AD patients to take part in an exercise-based randomized controlled trial (RCT) and have a cognitive outcome measure.
Results:
Six RCTs were identified that exclusively considered the effect of exercise in AD patients. Exercise generally had a positive effect on rate of cognitive decline in AD. A meta-analysis found that exercise interventions have a positive effect on global cognitive function, 0.75 (95% CI = 0.32-1.17).
Conclusions:
From the six studies reviewed, the evidence suggests that exercise can have a positive effect on rate of cognitive decline in AD. However, the variation between study designs makes conclusions regarding the optimum intervention on cognitive outcome in AD difficult. Well-designed and powered RCTs are still needed to ascertain the efficacy of exercise in slowing down cognitive impairment in AD patients. However, a positive initial indication for exercise efficacy justifies such efforts.
... 24 Currently, study findings on the treatment effect of aerobic exercise on AD symptoms are conflicting, which is largely due to the varying doses of aerobic exercise prescribed and delivered (adherence). 25,31 The differences in prescribed exercise doses are drastic among such a limited number of studies in AD: exercise frequency ranged from 1 to 5 times a week, session duration from 20 to 40 min, intensity from very low to moderate, and program duration from 5 weeks to 4 years. The majority of studies relied on caregivers to deliver exercise [10][11][12][13][14][15][16][17][18][19][20][21][22][23] with only 4 studies ascertaining the delivered exercise doses in real time. ...
... Those results demonstrate significant improvements from previous studies which had often used low exercise doses and reported 17%-90% adherence. 31 Reasons for retention success in this study are largely due to designing and conducting the study based on lessons learned from AD exercise and drug studies. Since adverse drug events were repeatedly identified as the main reason for dropout, this study was designed with participant safety as the cornerstone. ...
There is a pressing need to establish recruitment, retention, and adherence feasibility to inform clinical trials that will evaluate how exercise affects the symptoms and disease trajectory in Alzheimer's disease (AD). This paper reported the recruitment rate, retention, and adherence from a 6-month cycling study in community-dwelling older adults with mild-to-moderate AD using a single-group, repeated-measures design. Seven recruitment strategies were tested. Participants were prescribed an individualized, 15-45-min moderate intensity cycling 3 times a week for 6 months. The results showed a 1.87 recruitment rate (No. of participants recruited per month per site), 78.6% retention (No. of completers/No. of enrolled participants), and 86.4% adherence (number sessions meeting prescription dose/total number of sessions). The findings addressed a major gap in aerobic exercise studies in AD. Successful recruitment relies on community partnership, whereas strategies for ensuring participant exercise safety collectively improved retention and adherence.
... Aerobic exercise promotes adherence and compliance and is largely preferred by patients over balance, flexibility or strength exercises. Patients with dementia or those at risk of developing dementia should therefore be encouraged to undertake aerobic exercise, with a focus on the patient's adherence rather than on a fixed amount of exercise (142). Despite WHO recommendations to engage in a daily routine of physical activity and exercise to prevent sedentarism and avoid the development of risk factors such as diabetes and cardiovascular diseases, many elderly people particularly in developing countries do not have an active lifestyle. ...
With the aging of the world population, there has been a notable increase in the incidence of Alzheimer disease (AD), the most prevalent neurodegenerative disease affecting the elderly. Several studies have reported a delay in the onset of AD symptoms and age-related cognitive dysfunction upon changes to a healthier lifestyle. These positive adjustments find support in the cognitive reserve hypothesis, which holds that the ability to defer disease inception and protect cognitive performance is related to healthier lifestyle habits such as cognitive and physical activity, social engagement, and sensorial stimulation. These lifestyle habits can be compounded under the umbrella of the environmental enrichment (EE) paradigm. The mechanisms underlying EE’s capacity to modulate disease expression remain unclear. Since ethical and methodological considerations rule out direct analysis of such changes in the human brain, researchers have resorted to animal models to carry out in-depth characterizations of post-EE structural and functional brain modifications using a variety of behavioral, electrophysiological, genetic, biochemical, and biophysical approaches. Moreover, given the shorter lifespan of animals compared to humans, it is possible to address the effects of aging in control and AD models. In this review we analyze and classify EE data from studies using AD murine models and compare the setup variables employed. We also delve into various aspects of neuroplasticity, under the posit that this property is the key mechanistic process underlying the benefits of EE in both animal and human subjects.
... Dans le cadre d'une pratique d'EA, elle peut se mesurer à travers le nombre de séances qui sera réalisé par le patient, par rapport au nombre de séances programmées(283). La démotivation peut également se quantifier par l'intermédiaire du nombre d'abandon(284).Les études randomisées contrôlées ou non contrôlées ont été recherchées dans les bases dedonnées PubMED, science directe et Google Scholar en utilisant les mots clés suivants : faisabilité, entraînement aérobie, activité physique, endurance cardiorespiratoire, capacités cognitives, qualité de vie, personnes âgées et maladie d'Alzheimer (feasability, aerobic exercise, physical activity, aerobic fitness, cognitive capacities, quality of life). La recherche a été effectuée de Janvier à Février 2016 puis de nouveau de Février à Mars 2019. ...
L’entrainement aérobie (EA) montre des bénéfices sur la santé des personnes âgées présentant la maladie d’Alzheimer (MA) mais les mécanismes physiologiques expliquant ceux-ci restent à analyser. Les objectifs de ce travail étaient d’étudier la faisabilité d’un EA de type continu (EATC) ou intermittent (EATI) durant 9 semaines et de comparer leur effet sur : la synthèse plasmatique du facteur neurotrophique dérivé du cerveau (BDNFp), l’endurance cardiorespiratoire (EC), les capacités cognitives et la qualité de vie (QdV), chez des personnes âgées présentant la MA. Après EATC et EATI, aucun effet n’a été observé sur le taux de BDNFp et les performances cognitives. Une amélioration des paramètres d’endurance a été trouvée. La QdV était améliorée après EATC. Ce travail a montré que l’EATC et l’EATI sont faisables et efficaces indifféremment pour améliorer l’EC. L’EATC a eu un impact positif sur la QdV, mais les 2 types d’EA n’ont pas eu d’effet sur la synthèse de BDNFp et les capacités cognitives.
... Based on the evidence, the functional impact of aerobic exercise training in AD (FIT-AD) Model postulated that physical fitness (e.g. aerobic fitness) might be an important factor affecting ADL, and its effect on ADL is likely mediated by cognition, physical performance, and BPSD (Yu, 2011). ...
Understanding the factors affecting activities of daily living (ADL) is important in Alzheimer's disease (AD), because decline in ADL contributes to many poor health outcomes. Existing studies often investigate the factors in isolation without a theoretical framework. The purpose of the present study was to provide preliminary results on how cognition, physical performance, and behavioral and psychological symptoms of dementia mediate the relationship of aerobic fitness and ADL in AD. A cross‐sectional analysis was used (n = 28: average age 78 [8] years, education 16 (3) years, Mini‐Mental State Examination scores 20 [4]). The results showed that aerobic fitness is not linked to ADL directly, and its association with ADL was mediated by physical performance and global cognition. Our findings provide preliminary support for aerobic fitness as a potential therapeutic target, as enhanced aerobic fitness could simultaneously modify other factors affecting ADL. Nurses are in a unique position for coordinating exercise safety assessment and prescription and educating older adults with AD about exercise participation.
... In particular, studies found selective improvements in executive function rather than general cognitive benefits due to PA (23)(24)(25). Therefore, it is recommended to use a battery of neuropsychological tests rather than a single measure of cognition (14,26). For example, in a study that used multiple cognitive tests in oldestold women (selfreported), PA was associated with better scores in the modified MMSE, category fluency, and Trails B, but not for digit span backwards, phonemic fluency, and delayed recall at 5 years followup (27). ...
Physical fitness (PF) has been associated with improved cognition in older age, but less is known about its effects on different cognitive domains in individuals diagnosed with dementia. We explored the associations between PF and cognitive performance in 40 healthy elderly and 30 individuals with dementia. Participants completed a battery of standardized cognitive tests (Mini-Mental State Exam, Verbal Fluency, Prospective and Retrospective Memory Questionnaire, Clock Drawing, and California Verbal Learning Test) and were classified into high versus low levels of PF based on their score on the Physical Fitness Questionnaire. Analyses took into account age, gender, education, occupation, head injury, Internet use, brain training, and past levels of exercise and revealed overall benefits of PF, in particular for the people with dementia. Discriminant analysis showed high accuracy of reclassification, with most errors being due to the misclassification of dementia cases as healthy when they had high PF. The first discriminant function accounted for 83% of the variance. Using individual estimates of this function, which reflected global cognitive performance, confirmed the beneficial role of PF in dementia, even when taking into account age, past level of exercise, and the number of years since the dementia diagnosis. Finally, univariate analyses confirmed the differential sensitivity of the cognitive tests, with MMSE and clock drawing showing reliable interaction effects. This work shows that PF is associated with a reduced level of cognitive deterioration expected with dementia, especially in executive functioning and provides empirical support for the cognitive benefits of interventions promoting PF for individuals with dementia.
... In particular, studies found selective improvements in executive function rather than general cognitive benefits due to physical activity (Colcombe and Kramer, 2003;Kramer et al., 1999;Smiley-Oyen et al., 2008). Therefore, it is recommended to use a battery of neuropsychological tests rather than a single measure of cognition (Yu, 2011;Farina et al., 2014). For example, in a study that used multiple cognitive tests in oldest-old women, (self-reported) physical activity was associated with better scores in the modified MMSE, category fluency and Trails B, but not for digit span backwards, phonemic fluency and delayed recall at five years follow-up . ...
Background
Whereas the association between individual lifestyle behaviours and dementia risk has been well researched, their combined influence is poorly understood. We examined dementia risk in relation to clusters of lifestyle behaviours in a representative sample of English older adults.
Methods
Data from 3975 men and women (≥60 years) participating in the English Longitudinal Study of Ageing were analysed with latent class analysis. We assessed different clusters of lifestyle behaviours (physical activity levels, consumption of fruit and vegetables, alcohol consumption, smoking behaviour) at wave 3 (considered for these analyses as the baseline), in association with new dementia cases 8 years later (wave 7). Age, sex, marital status, education, memory ability, symptoms of depression, body-mass index, stroke, hypertension, and coronary heart disease, measured at baseline, were included as covariates.
Findings
From the overall sample, 5% (n=178) developed dementia at wave 7. We identified two distinctive classes of lifestyle behaviours at baseline that were predictive of subsequent dementia, which mainly varied by physical activity levels. 1222 (60%) of 2037 individuals in class I were physically active, 1425 (70%) consumed at least five portions of fruit and vegetables, 672 (33%) drank alcohol daily, and 102 (<1%) were smokers. By contrast, individuals in class II (n=1938) were less likely to be physically active (<1 %, n=174), 52% (1007) had a high intake of fruit and vegetables, and only a minority smoked or drank daily (<20%, 310 and 233, respectively). One in 100 individuals from class I and one in ten individuals from class II developed subsequent dementia. Individuals clustered in class I had a lower risk of dementia 8 years later, than did those in class II (odds ratio 0·16, 95% CI 0·11–0·21).
Interpretation
This observational study does not establish the causal status of lifestyle factors associated with dementia risk. It does, however, suggest that physical inactivity should be targeted in future dementia prevention trials targeting modifiable risk factors.
Funding
National Institute on Aging (NIA) (grant 528122), NIA (grant RO1AG7644), and a consortium of UK government departments coordinated by the Economic and Social Research Council (ESRC).
... Aerobic exercise, alone or in the context of EE (see [6] for a review of EE effects), seems to be a powerful activity to delay neurodegenerative processes. Evidence is available on the positive effects of HIAA (such as walking, biking, or rowing) on cognition (better memory and executive functions), neuroplasticity (in the frontal and hippocampal brain regions), and maximal cardiorespiratory fitness (also named 'maximal aerobic fitness' or 'maximal oxygen consumption', VO 2 max) in healthy older adults and subjects with dementia [7][8][9]. Moreover, animals' studies showed positives effects of MIAA and HIAA on cerebral aerobic metabolism, which can reduce alterations in the bioenergy metabolism (e.g., increase of mitochondria functioning in the brain cells [10]). ...
Background:
The use of Serious exerGames (SeG) as enriched environments (EE), which promotes cognitive simulation with physical activity in a positive emotional context, has been proposed to represent a powerful method to slow down the decline due to neurodegenerative diseases (ND), such as Alzheimer's disease (AD). However, so far, no SeG targeting EE has been tested in ND subjects.
Objective:
This study aimed at evaluating the usability and short-term training effects of X-Torp, an action SeG designed for elderly ND subjects with mild cognitive impairment (MCI) and AD.
Methods:
X-Torp is a SeG played using the Microsoft® Kinect™. 10 ND subjects and 8 healthy elderly controls (HEC) were enrolled in a 1-month program with three training sessions per week. Usability was evaluated through game time, game performance, the aerobic intensity level reached, perceived emotions, and perceived usability.
Results:
All participants successfully completed the training program. ND subjects played less and had a lower game performance compared to HEC. During the sessions, ND subjects maintained a light intensity of aerobic activity, while HEC maintained a moderate intensity. Both groups experienced only positive emotions, and reported a 'moderate' to 'high' perceived competence, a 'moderate' game difficulty, and a 'high' interest in the game.
Conclusion:
Usability results suggest that X-Torp represents a usable EE for healthy subjects and persons with MCI and AD. However, in order to reach moderate or high intensity of aerobic activity, X-Torp control modes should be adapted to become more physically stimulating.
... There is major interest nowadays in Moderate-High Intensity Aerobic Activities (MHIAA) for non-pharmacological interventions in elderly suffering from neurodegenerative diseases like Alzheimer's Disease and Related Disorders (ADRD) [1,2]. More and more evidence is available on the positive effects of MHIAA on neuroplasticity, cardiorespiratory fitness and ADRD, in particular concerning locomotion exercises such as walking, biking or rowing [3][4][5]. Nevertheless, the monotony of the practice of these activities is an important drawback, which has lead to the development of video games for physical exercises (or exergames) to make it more attractive [6,7]. The most common and affordable exergames allow the player to interact with the game using motion sensors based on RGB-D cameras (Red Green Blue + Depth) for the Microsoft 1 Kinect TM . ...
Aim:
RGB-D cameras (Red Green Blue+Depth) are widely employed in exergames designed to physically stimulate elderly people. Nevertheless, the intensity of the physical activity reached with the existing solutions is rarely sufficient to obtain a real impact on the physical fitness and thus on the health status of this population. In this context, a Point Cloud Based System (PCBS) has been developed to interface ordinary motorized treadmills with exergames through a simple RGB-D camera, to induce players to perform physical activities at higher intensities. The goal of this study was to assess the accuracy and reliability of PCBS to measure the walking speed of a subject on a standard motorized treadmill based on the image streams of an RGB-D camera.
Methods:
36 participants performed three 10min walking exercises, divided in 5 blocks of 2min at the following constant ordered speeds: 0.42, 0.69, 0.97, 1.25 and 1.53ms(-1). The measured walking speeds are compared to those obtained through a Marker Based Control System (MBCS).
Results:
Results showed a high system accuracy (bias: 0.013±0.015ms(-1)), a good reliability (ICC=0.63-0.91) and a low variability (SEM=1-5%; MD=2.7-14%).
Discussion:
Accuracy and reliability of PCBS are consistent with those obtained in similar existing systems measuring gait parameters.
Conclusion:
Within the context of the development of exergames, PCBS may be combined with exergames to perform physical activities at sufficiently high intensities in the elderly population, in order to improve their physical health and possibly prevent/delay cognitive impairment.
... Tanto el estrés oxidativo como la inflamación son mecanismos desencadenantes de la patología de esta enfermedad por lo que tanto su estudio como sus posibles interacciones, pueden contribuir al desarrollo de nuevas terapias farmacológicas en el tratamiento del Alzheimer. Desde el punto de vista no farmacológico, diversas estrategias se han considerado beneficiosas en cuanto a la mejora del bienestar y calidad de vida de los pacientes (Olazarán et al., 2004;Guetin et al., 2009;Ramesh et al., 2010;Fang., 2011; Sant'Anna y Morat., 2013). Maniobras como la musicoterapia, fisioterapia, psicomotricidad, cuidados básicos, terapia ocupacional, laboraterapia, terapia con animales y la psicoestimulación cognitiva se consideran herramientas muy útiles encaminadas a ejercitar y reforzar capacidades cognitivas que todavía preserva el paciente de Alzheimer sin pretender recuperar las que ya se han perdido (Olazarán et al., 2004;Guetin et al., 2009 (Asensi et al., 2011). ...
Several studies indicate that the accumulation of Aβ1-42 peptide in Alzheimer's disease is the inducer of the inflammatory process with the activation of glial cells producing and releasing inflammatory cytokines (Eikelenboom and van Gool., 2004; Zhu, X et al., 2004). The presence of these inflammatory molecules induced by Aβ1-42 stimulates the production of reactive oxygen species and free radicals by glial cells increasing the levels of oxidative stress (Jiménez-Jiménez et al., 2006; Sutherland et al., 2013; Phillips et al., 2013; Gubandru et al., 2013). Collectively, inflammation and oxidative stress, indicating a key role in the development and progression of Alzheimer's disease. Currently, there is no cure for Alzheimer's disease and the pharmacological therapeutic targets to delay and control their symptoms to improve the welfare and quality of life of the patient. Because of the side effects that these drugs have, since several years are being developed lines of research to study the different effects (neuroprotective, antioxidant and anti-inflammatory) of natural compounds based on the action on different signaling pathways associated with inflammation and oxidative stress. Among have been proposed polyphenols and cannabinoids. The studies were performed in primary cultures of astrocytes, because they are the cells involved in the inflammatory response and found in greater amounts in the brain. They have employed the techniques of direct and indirect immunofluorescence, MTT, Western-blot, ELISA and HPLC assay for the various determinations in the different experimental conditions (control, treated with Aβ1-42 peptide and pre-treatment with polyphenols and cannabinoids). Our results indicate that pre-treatment with polyphenols or cannabinoids are able to reduce inflammation and oxidative stress induced by Aβ1-42 peptide, decreasing of pro-inflammatory and oxidant molecules (IL-1β, TNF-α, COX -2, iNOS, GSSG/GSH) and increased anti-inflammatory and anti-oxidant molecules (PPAR-γ, SOD Cu/Zn). These results support the hypothesis that inflammation and oxidative stress mechanisms contribute significantly to the pathogenesis of Alzheimer's disease and suggest the use of natural compounds such as polyphenols or cannabinoids to reduce the progression of damage.
... Recent reviews have noted the lack of CPET-based aerobic exercise prescription in clinical trials. 7 When considering cardiopulmonary exercise testing for persons with cognitive impairment, several concerns have been expressed such as the reliability of the test for research or exercise prescription, 3 and impaired communication and understanding during the CPET. 8 Additional concerns may include poor safety awareness and the potential for behavioral disturbance. ...
To retrospectively assess whether CPET would be well-tolerated in individuals with AD compared to a nondemented peer group.
We retrospectively reviewed 575 CPET in individuals with and without cognitive impairment due to AD. Setting: University medical center.
Exercise testing data was reviewed from non-demented individuals (n = 340) and those with Alzheimer's-related cognitive impairment (n = 235).
Not applicable.
Main outcome measure for this study was reporting the reason for CPET termination. The hypothesis reported was formulated after data collection.
We found that the CPET on cognitively impaired individuals were terminated as a result of fall risk more often but that overall test termination was infrequent, 5.5% vs 2.1% (p=0.04) in peers without cognitive impairment. We recorded 6 cardiovascular and 7 fall risk events in those with AD, compared to 7 cardiovascular and 0 fall risk events in those without cognitive impairment.
Our findings support using CPET to assess peak VO2 in older adults with cognitive impairment due to AD.
... It has been shown that adults with AD can benefi t from exercise interventions to improve mobility. [57][58][59][60] Physical therapy for mobility defi cits for those in the very early stage of AD may prove particularly benefi cial. ...
Studies have shown that adults with Alzheimer disease (AD) have gait and balance deficits; however, the focus has been on those with mild to severe disease. The purpose of this study was to determine whether balance and gait deficits are present in those with very mild AD.
Thirteen adults (72.9 ± 4.7 years old) with very mild AD and 13 age-matched (72.6 ± 4.6 years old) and sex-matched (10 males and 3 females) participants in a control group without AD performed balance and gait tests. All participants were living in the community and independent in community ambulation.
Participants with very mild AD had shorter times in tandem stance with eyes open (P < 0.001) and with eyes closed (P = 0.007) compared with participants in the control group. Those with AD also took longer to complete the Timed "Up & Go" Test (P < 0.001). Gait deficits were found for those with AD as demonstrated by slower velocities in the 10-m walk at a comfortable pace (P = 0.029) and on an instrumented walkway (P < 0.001). Stance times were longer for those with AD (P < 0.001) and step length was shorter (P = 0.001). There were no group differences in the 10-m walk at a fast pace. The gait velocity of participants in the control group was faster on the instrumented walkway than in the 10-m walk at a comfortable pace (P = 0.031). In contrast, the gait velocity of those with AD was significantly slower on the instrumented walkway than in the 10-m walk at a comfortable pace (P = 0.024).
Balance and gait deficits may be present in those in the very early stages of AD. Novel surfaces may affect gait speed in those with very mild AD. Identifying mobility deficits early in the progression of AD may provide an opportunity for early physical therapy intervention, thus promoting continued functional independence.
Adults in the very early stages of AD may show signs of balance and gait deficits. Recognition of these problems early with subsequent physical therapy may slow the progression of further balance and gait dysfunction.
Background:
Alzheimer's disease (AD), as the most common cause of dementia, brings huge economic burden for patients and social health care systems, which motivates researchers to study multiple protective factors, among which physical activity and exercise have been proven to be both effective and economically feasible.
Methods:
A systematic literature search was performed for eligible studies published up to November 1st 2018 on three international databases (PubMed, Cochrane Library, and Embase) and two Chinese databases (Wanfang Data, China National Knowledge Infrastructure). All analyses were conducted using Stata 14.0. Due to heterogeneity between studies, a random-effects model was used for this meta-analysis. Meta-analysis was used to explore if physical activity and exercise can exert positive effects on cognition of elderly with AD and subgroup analyses were conducted to find out if there are dose-response effects.
Results:
A total of 13 randomized controlled trials were included with a sample size of 673 subjects diagnosed with AD. Intervention groups showed a statistically significant improvement in cognition of included subjects measured by the MMSE score (SMD = 1.12 CI:0.66~1.59) compared to the control groups. Subgroup analyses showed different amounts of physical activity and exercise can generate different effects.
Conclusions:
As one of few meta-analyses comparing different quantities of physical activity and exercise interventions for AD in details, our study suggests that physical activity and exercise can improve cognition of older adults with AD. While the concomitant effects on cognition functions of high frequency interventions was not greater than that of low frequency interventions, the threshold remains to be settled. However, more RCTs with rigorous study design are needed to support our findings.
Ce travail de thèse présente une approche clinique et thérapeutique visant à fournir de nouvelles techniques de soins pour les patients atteints de troubles neurocognitifs et notamment de maladie d’Alzheimer. Les serious exergames sont des jeux vidéo sérieux intégrant une activité physique. Ils peuvent constituer des outils de production d’environnement enrichi pour les utilisateurs, en associant notamment exercice physique et entraînement cognitif. L’objectif de cette thèse est d’explorer en quoi les serious exergames peuvent contribuer à la prise en charge non médicamenteuse des troubles neurocognitifs. Dans ce travail, nous avons réalisé deux types de contribution. Les premières contributions sont générales, l’une présente notre approche clinique intégrative combinant exercice physique et entraînement cognitif via l’utilisation de serious exergames, et l’autre présente des recommandations concernant l’usage des serious games. Les secondes contributions sont de nature expérimentale. La première expérimentation vise à vérifier une des bases théoriques de notre approche clinique. Les deux expérimentations suivantes constituent une évaluation de la mise en œuvre de notre approche.
This study examined the determinants of physical activity (PA) for older adults with Alzheimer's disease (AD) to learn more about how to promote PA in this population. Caregivers of older adults with AD (N = 99) provided information related to care recipient's PA, as well as addressed sociodemographics and perceptions about their care recipient's PA. Gender of care recipient was a significant predictor of PA (β = .80, P < .05); men with AD participated in more PA than women with AD. Also, caregiver's outcome expectation for care recipient's PA also predicted more PA (β = .82, P < .05). Caregiver's perceived benefits of PA (outcome expectation) for their care recipient partially mediated the relationship between self-efficacy for care recipient's PA and the reported levels of PA for the care recipient. This study demonstrated the importance of caregiver perceptions about care recipient's PA.
Executive dysfunction occurs early and is prevalent in Alzheimer's disease (AD). This study tested the ability of different measures for identifying changes in executive function and the effect of 6-months of aerobic exercise on executive function in older adults with mild to moderate AD, using a single-group, repeated-measures design (n = 28, age 78.1 ± 8.37). Factor analysis and linear mixed-effects model analyses showed that individually the Exit Interview-25 (EXIT-25), Behavioral Dyscontrol Scale (BDS), and Golden Stroop test were the preferred instruments for measuring changes in executive function in the sample. The COWAT and TMT had substantial floor effects limiting their ability to identify changes in executive function. A single latent factor was sufficient to describe the heterogeneity of executive function. Over 6 months, aerobic exercise maintained executive function (effect size = -0.11, -0.24, -0.27, and -0.21 for the EXIT-25, BDS, Stroop, and latent factor, respectively). Decline in the latent factor (effect size = -0.21, p = 0.06) was minimal and comparable to that in global cognition (effect size = -0.20, p = 0.34). Aerobic exercise may be effective on maintaining executive function in AD.
Both acute sleep loss and chronic sleep loss are common in our society. Insufficient sleep can be detrimental to cognition and health, and disturbed sleep is frequently observed with neurodegenerative pathologies. Conversely, exercise has beneficial effects on cognition and neurocognitive health. Interestingly, many of the same molecules and cellular pathways that alter sleep and are modulated by sleep loss are also affected by exercise including cytokines and nitric oxide synthase of the innate immune system. In general, brain proinflammatory molecules are enhanced by sleep loss and induce sleepiness, while anti-inflammatory molecules attenuate these effects. Acute exercise enhances brain proinflammatory molecules, while exercise training appears to exhibit anti-inflammatory properties that are protective against pathologies. Recent evidence indicates interactions between sleep loss and exercise on modulating inflammatory- and neurocognitive-related molecules, cognition, and disease. Consequently, we discuss the role of sleep in cognition, immunity, and disease and its interactions with exercise.
Objective To evaluate the effect of aerobic exercise on cognitive function in people with mild cognitive impairment (MCI).
Design Systematic review and meta-analysis of aerobic exercise intervention for cognitive function in older adults with MCI.
Data sources PubMed, EMBASE, SinoMed, China National Knowledge Infrastructure (CNKI), Wanfang and Chinese Science and Technology Periodical (VIP) databases from their inception to 31 January 2015, the Cochrane Central Register of Controlled Trials (Cochrane Library, 2015, Issue 3) and the reference lists of all retrieved articles.
Eligibility criteria Randomised controlled trials, older adults with MCI, aerobic exercises compared with no specific exercise intervention for global cognitive ability and any specific domains of cognition.
Data synthesis Meta-analysis was conducted with RevMan V.5.3 software using the fixed-effect model for the available data without significant heterogeneity, or the random-effect model was used if appropriate.
Results 11 studies were identified involving 1497 participants. Meta-analysis showed that aerobic exercise significantly improved global cognitive ability (Mini-Mental State Examination (MMSE) scores: MD=0.98, 95% CI 0.5 to 1.45, p<0.0001; Montreal Cognitive Assessment (MoCA) scores: MD=2.7, 95% CI 1.11 to 4.29, p=0.0009); weakly, positively improve memory (immediately recall: SMD=0.29, 95% CI 0.13 to 0.46, p=0.0005; delay recall: SMD=0.22, 95% CI 0.09 to 0.34, p=0.0005). No significant improvement was found in other domains of cognition.
Conclusions Aerobic exercise led to an improvement in global cognitive ability and had a positive effect with a small effect size on memory in people with MCI. However, owing to the limitations of the included studies, these findings should be interpreted cautiously.
Alzheimer's disease is a progressive neurodegenerative disorder leading to cognitive decline, personality changes, global mental dysfunction and functional incapacity. The disease is one of the primary causes of morbidity in older adults and constitutes a significant burden for the patients, their families and the health system. This is a review of current data on the role of exercise in the prevention of and therapeutic approach to Alzheimer's disease. A growing body of evidence from epidemiological studies indicates that increased physical activity may reduce the incidence of Alzheimer's disease or delay the progression of the disease in older adults. Exercise is an important cost-effective, safe, non-pharmacological intervention, as it appears to lower the parameters associated with the pathophysiology of the disease, improve cognitive function, functional capacity and quality of life and contribute to the prevention and rehabilitation of co-morbid chronic diseases in the elderly. Appropriate attention should be given to the characteristics of exercise training. Exercise programs should be pleasant to follow and adapted to the needs of individual patients. In addition, they should be implemented with a view to safety, supervision and careful planning, in order to ensure long-term adherence. A mixed training programme, including aerobic, muscle strengthening, balance and flexibility exercises, is recommended as the most beneficial for individuals with Alzheimer's disease. The provision of information to the elderly, the patients with Alzheimer's disease and their families about the benefits of exercise, and the collaboration of all the relevant health professionals are two particularly important components in the promotion of physical activity as a means of improving the quality of life, even in the frail aged population.
Over the last decade transcriptome studies of postmortem tissue from subjects with schizophrenia revealed that synaptic, mitochondrial, immune system, GABA-ergic and oligodendrocytic changes are all integral parts of the disease process. The combined genetic and transcriptomics studies argue that the molecular underpinnings of the disease are even more varied than the symptomatic diversity of schizophrenia. Ultimately, to decipher the pathophysiology of human disorders in general, we will need to understand the function of hundreds of genes and regulatory elements in our genome, and the consequences of their overexpression and reduced expression in a developmental context. Furthermore, integration of knowledge from various data sources remains a monumental challenge that has to be systematically addressed in the upcoming decades. In the end, our success in interpreting the molecular changes in schizophrenia will depend on our ability to understand the biology using innovative ideas and cannot depend on the hope of developing novel, more powerful technologies.
The subjective experience of participating in aerobic exercise is unknown in Alzheimer's disease (AD).
The purpose of this study was to understand the subjective perceptions of the feasibility and impact of a 6-month, moderate-intensity aerobic exercise intervention by older adults with AD and their family caregivers.
Ten older adults with AD who completed the intervention and their family caregivers participated in four focus group interviews.
Four converging themes were identified: "There was no perceived positive change in cognitive symptoms," "The 6-month exercise program was socially rewarding," "The 6-month exercise program increased physical strength," and "Participation in aerobic exercise was a positive experience." Family caregivers further identified two additional themes: "The exercise program led to improved attitude in older adults with AD" and "The exercise program reduced caregiver stress."
Aerobic exercise is a feasible and well-perceived intervention for older adults with AD and their family caregivers.
The longitudinal influences on physical capacity and habitual aerobic activity level in the early stages of Alzheimer's disease (AD) are unclear. Therefore, changes in physical capacity and aerobic activity level were evaluated. Twenty-five individuals with AD were assessed annually for 2 years, by 10-m walk test, 6-minute walk test, and timed up-and-go (TUG) single/dual tasks. Habitual aerobic activity was assessed by diary registrations. The AD group showed a lower physical capacity than controls at baseline but comparable levels of aerobic activity. During the follow-up period, physical capacity declined in the AD group, but the aerobic activity levels changed only marginally. Our results show that in the early stages of AD, people are capable of maintaining health-promoting aerobic activity levels, despite a decline in their physical capacity. Additionally, it appears that cognitive dysfunction contributes to an impaired physical capacity. The TUG tasks might, therefore, be useful for detecting early signs of cognitive impairment.
Few trials examined these important outcomes. In addition, family caregiver outcomes and use of health care services were not reported in any of the included studies. There is some evidence that physical activity delays the onset of dementia in healthy older adults and slows down cognitive decline to prevent the onset of cognitive disability. Studies using animal models suggest that physical activity has the potential to attenuate the pathophysiology of dementia. Four trials met the inclusion criteria. However, only two trials were included in the analyses because the required data from the other two trials were not made available. Further well-designed research is required.
To examine factors associated with adherence to a walking program in community-dwelling individuals with Alzheimer's disease (AD).
Data were analyzed for 66 participants with AD asked to walk 30 continuous minutes per day. Adherence data (number of days walked, minutes walked, days walked 30+ minutes) were obtained from daily logs. Predictor variables included age, spousal relationship, health limitations, depression, participant dementia severity and behavioral disturbance, and caregiver stress and dementia management style.
During week 1, participants significantly (P < .0001) increased number of days walked/week compared to baseline. However, walking frequency and duration declined over 6 months. Nonwalkers had higher behavioral disruption scores. Regression analyses indicated that participants who walked more were less depressed. Caregivers of walking participants tended to be spouses, and reported less stress.
Both participant and caregiver factors (participant behavioral disruption and depression; caregiver stress and spousal relationship) impacted whether community-dwelling individuals with AD adhered to a walking program.
To assess the effects of aerobic exercise training on neurocognitive performance. Although the effects of exercise on neurocognition have been the subject of several previous reviews and meta-analyses, they have been hampered by methodological shortcomings and are now outdated as a result of the recent publication of several large-scale, randomized, controlled trials (RCTs).
We conducted a systematic literature review of RCTs examining the association between aerobic exercise training on neurocognitive performance between January 1966 and July 2009. Suitable studies were selected for inclusion according to the following criteria: randomized treatment allocation; mean age > or =18 years of age; duration of treatment >1 month; incorporated aerobic exercise components; supervised exercise training; the presence of a nonaerobic-exercise control group; and sufficient information to derive effect size data.
Twenty-nine studies met inclusion criteria and were included in our analyses, representing data from 2049 participants and 234 effect sizes. Individuals randomly assigned to receive aerobic exercise training demonstrated modest improvements in attention and processing speed (g = 0.158; 95% confidence interval [CI]; 0.055-0.260; p = .003), executive function (g = 0.123; 95% CI, 0.021-0.225; p = .018), and memory (g = 0.128; 95% CI, 0.015-0.241; p = .026).
Aerobic exercise training is associated with modest improvements in attention and processing speed, executive function, and memory, although the effects of exercise on working memory are less consistent. Rigorous RCTs are needed with larger samples, appropriate controls, and longer follow-up periods.
Alzheimer's disease (AD) is a progressive neurodegenerative disorder affecting the elderly population. It is predicted that the incidence of AD will be increased in the future making this disease one of the greatest medical, social, and economic challenges for individuals, families, and the health care system worldwide. The etiology of AD is multifactorial. It features increased oxidative state and deposition of amyloid plaques and neurofibrillary tangles of protein tau in the central cortex and limbic system of the brain. Here we provide an overview of the positive impacts of exercise on this challenging disease. Regular physical activity increases the endurance of cells and tissues to oxidative stress, vascularization, energy metabolism, and neurotrophin synthesis, all important in neurogenesis, memory improvement, and brain plasticity. Although extensive studies are required to understand the mechanism, it is clear that physical exercise is beneficial in the prevention of AD and other age-associated neurodegenerative disorders.
To study the effects of physical stimulation based on walking exercises, equilibrium and endurance on cognitive function and walking efficiency in patients with dementia.
Randomized controlled trial including 31 subjects suffering from dementia (age: 81.8 +/- 5.3 years). The intervention group (n = 16) benefited from a 15-week physical activity programme involving three 1-hour sessions per week. The control group (n = 15) did not practice any physical activities. Before and after rehabilitation, all subjects were evaluated with the Rapid Evaluation of Cognitive Functions test (ERFC French version) and walking analysis.
After the 15 weeks of rehabilitation, the subjects from the intervention group improved their overall ERFC score (p < 0.01), while those in the control group decreased their overall ERFC score. Interactions were also observed between walking parameters and groups (p < 0.01); the intervention group improved walking capacities through heightened walking speed, stride length and a reduction in double limb support time. Lastly, the subjects from the control group presented a reduction in both walking speed and stride length.
This study shows that a physical activity programme can slow cognitive decline and improve quality of walking in elderly persons suffering from dementia.
To examine the effects of aerobic exercise on cognition and other biomarkers associated with Alzheimer disease pathology for older adults with mild cognitive impairment, and assess the role of sex as a predictor of response.
Six-month, randomized, controlled, clinical trial.
Veterans Affairs Puget Sound Health Care System clinical research unit.
Thirty-three adults (17 women) with amnestic mild cognitive impairment ranging in age from 55 to 85 years (mean age, 70 years). Intervention Participants were randomized either to a high-intensity aerobic exercise or stretching control group. The aerobic group exercised under the supervision of a fitness trainer at 75% to 85% of heart rate reserve for 45 to 60 min/d, 4 d/wk for 6 months. The control group carried out supervised stretching activities according to the same schedule but maintained their heart rate at or below 50% of their heart rate reserve. Before and after the study, glucometabolic and treadmill tests were performed and fat distribution was assessed using dual-energy x-ray absorptiometry. At baseline, month 3, and month 6, blood was collected for assay and cognitive tests were administered.
Performance measures on Symbol-Digit Modalities, Verbal Fluency, Stroop, Trails B, Task Switching, Story Recall, and List Learning. Fasting plasma levels of insulin, cortisol, brain-derived neurotrophic factor, insulinlike growth factor-I, and beta-amyloids 40 and 42.
Six months of high-intensity aerobic exercise had sex-specific effects on cognition, glucose metabolism, and hypothalamic-pituitary-adrenal axis and trophic activity despite comparable gains in cardiorespiratory fitness and body fat reduction. For women, aerobic exercise improved performance on multiple tests of executive function, increased glucose disposal during the metabolic clamp, and reduced fasting plasma levels of insulin, cortisol, and brain-derived neurotrophic factor. For men, aerobic exercise increased plasma levels of insulinlike growth factor I and had a favorable effect only on Trails B performance.
This study provides support, using rigorous controlled methodology, for a potent nonpharmacologic intervention that improves executive control processes for older women at high risk of cognitive decline. Moreover, our results suggest that a sex bias in cognitive response may relate to sex-based differences in glucometabolic and hypothalamic-pituitary-adrenal axis responses to aerobic exercise.
More than 25 million people in the world today are affected by dementia, most suffering from Alzheimer's disease. In both developed and developing nations, Alzheimer's disease has had tremendous impact on the affected individuals, caregivers, and society. The etiological factors, other than older age and genetic susceptibility, remain to be determined. Nevertheless, increasing evidence strongly points to the potential risk roles of vascular risk factors and disorders (eg, cigarette smoking, midlife high blood pressure and obesity, diabetes, and cerebrovascular lesions) and the possible beneficial roles of psychosocial factors (eg, high education, active social engagement, physical exercise, and mentally stimulating activity) in the pathogenetic process and clinical manifestation of the dementing disorders. The long-term multidomain interventions toward the optimal control of multiple vascular risk factors and the maintenance of socially integrated lifestyles and mentally stimulating activities are expected to reduce the risk or postpone the clinical onset of dementia, including Alzheimer's disease.
The human brain gradually loses tissue from the third decade of life onward, with concomitant declines in cognitive performance. Given the projected rapid growth in aged populations, and the staggering costs associated with geriatric care, identifying mechanisms that may reduce or reverse cerebral deterioration is rapidly emerging as an important public health goal. Previous research has demonstrated that aerobic fitness training improves cognitive function in older adults and can improve brain health in aging laboratory animals, suggesting that aerobic fitness may provide a mechanism to improve cerebral health in aging humans. We examined the relationship between aerobic fitness and in vivo brain tissue density in an older adult population, using voxel-based morphometric techniques.
We acquired high-resolution magnetic resonance imaging scans from 55 older adults. These images were segmented into gray and white matter maps, registered into stereotaxic space, and examined for systematic variation in tissue density as a function of age, aerobic fitness, and a number of other health markers.
Consistent with previous studies of aging and brain volume, we found robust declines in tissue densities as a function of age in the frontal, parietal, and temporal cortices. More importantly, we found that losses in these areas were substantially reduced as a function of cardiovascular fitness, even when we statistically controlled for other moderator variables.
These findings extend the scope of beneficial effects of aerobic exercise beyond cardiovascular health, and they suggest a strong solid biological basis for the benefits of exercise on the brain health of older adults.
Because of the influence of cardiorespiratory fitness on functional independence, quality of life, and cardiovascular disease and all-cause mortality, tremendous interest has been directed towards describing the age-related change in maximal oxygen consumption (VO(2max)). Current evidence supports a 10% per decade decline in VO(2max) in men and women regardless of activity level. High-intensity exercise may reduce this loss by up to 50% in young and middle-aged men, but not older men, if maintained long term. Middle-aged and older women do not appear to be able to reduce loss rates in VO(2max) to less than 10% per decade, which may be related to estrogen status. However, maintaining high-intensity training seems limited to approximately one decade at best and to a select few individuals. While the factors limiting the ability to maintain high-intensity training are not completely known, aging most likely plays a role as studies have demonstrated that training maintenance becomes more difficult with advancing age. Age-related loss of VO(2max) seems to occur in a non-linear fashion in association with declines in physical activity. In sedentary individuals, this non-linear decline generally occurs during the twenties and thirties whereas athletic individuals demonstrate a non-linear decline upon decreasing or ceasing training. Non-linear loss rates are also demonstrated in individuals over the age of 70 years. The decline in VO(2max) seems to be due to both central and peripheral adaptations, primarily reductions in maximal heart rate (HR(max)) and lean body mass (LBM). Exercise training does not influence declines in HR(max), while LBM can be maintained to some degree by exercise. Recommendations for exercise training should include aerobic activities utilising guidelines established by the American College of Sports Medicine for improving CV fitness and health, as well as strength training activities for enhancing LBM.
Exercise training for patients with Alzheimer disease combined with teaching caregivers how to manage behavioral problems may help decrease the frailty and behavioral impairment that are often prevalent in patients with Alzheimer disease.
To determine whether a home-based exercise program combined with caregiver training in behavioral management techniques would reduce functional dependence and delay institutionalization among patients with Alzheimer disease.
Randomized controlled trial of 153 community-dwelling patients meeting National Institute of Neurological and Communicative Diseases and Stroke/Alzheimer Disease and Related Disorders Association criteria for Alzheimer disease, conducted between June 1994 and April 1999.
Patient-caregiver dyads were randomly assigned to the combined exercise and caregiver training program, Reducing Disability in Alzheimer Disease (RDAD), or to routine medical care (RMC). The RDAD program was conducted in the patients' home over 3 months.
Physical health and function (36-item Short-Form Health Survey's [SF-36] physical functioning and physical role functioning subscales and Sickness Impact Profile's Mobility subscale), and affective status (Hamilton Depression Rating Scale and Cornell Depression Scale for Depression in Dementia).
At 3 months, in comparison with the routine care patients, more patients in the RDAD group exercised at least 60 min/wk (odds ratio [OR], 2.82; 95% confidence interval [CI], 1.25-6.39; P =.01) and had fewer days of restricted activity (OR, 3.10; 95% CI, 1.08-8.95; P<.001). Patients in the RDAD group also had improved scores for physical role functioning compared with worse scores for patients in the RMC group (mean difference, 19.29; 95% CI, 8.75-29.83; P<.001). Patients in the RDAD group had improved Cornell Depression Scale for Depression in Dementia scores while the patients in the RMC group had worse scores (mean difference, -1.03; 95% CI, -0.17 to -1.91; P =.02). At 2 years, the RDAD patients continued to have better physical role functioning scores than the RMC patients (mean difference, 10.89; 95% CI, 3.62-18.16; P =.003) and showed a trend (19% vs 50%) for less institutionalization due to behavioral disturbance. For patients with higher depression scores at baseline, those in the RDAD group improved significantly more at 3 months on the Hamilton Depression Rating Scale (mean difference, 2.21; 95% CI, 0.22-4.20; P =.04) and maintained that improvement at 24 months (mean difference, 2.14; 95% CI, 0.14-4.17; P =.04).
Exercise training combined with teaching caregivers behavioral management techniques improved physical health and depression in patients with Alzheimer disease.
To determine by meta-analysis whether physical exercises are beneficial for people with dementia and related cognitive impairments.
Published articles and nonpublished manuscripts from 1970 to 2003 were identified by using electronic and manual searches. Key search words included exercise, rehabilitation, activities of daily living, dementia, Alzheimer's disease, aged, and geriatrics.
Reviewed studies were limited to randomized trials evaluating exercise in persons 65 years of age or older with cognitive impairment. Studies included quantitative results (means, standard deviations, t tests, F tests) for physical fitness, physical functioning, cognition, or behavior outcomes.
One reviewer extracted data on study characteristics and findings. Selected articles were evaluated for methodologic quality by 2 raters.
A total of 2020 subjects participated in the 30 trials that met the inclusion criteria. Summary effects were computed using a fixed effects (Hedge's g(i)) model. Significant summary effect sizes (ES) were found for strength (ES=.75; 95% confidence interval [CI], .58-.92), physical fitness (ES=.69; 95% CI, .58-.80), functional performance (ES=.59; 95% CI, .43-.76), cognitive performance (ES=.57; 95% CI, 0.43-1.17), and behavior (ES=.54; 95% CI, .36-.72). The overall mean ES between exercise and nonexercise groups for all outcomes was .62 (95% CI, .55-.70).
Exercise training increases fitness, physical function, cognitive function, and positive behavior in people with dementia and related cognitive impairments.
To evaluate whether a comprehensive sleep education program (Nighttime Insomnia Treatment and Education for Alzheimer's Disease (NITE-AD)) could improve sleep in dementia patients living at home with their family caregivers.
A randomized, controlled trial.
Thirty-six community-dwelling patients with Alzheimer's disease (AD) and their family caregivers.
All participants received written materials describing age- and dementia-related changes in sleep and standard principles of good sleep hygiene. Caregivers in active treatment (n=17) received specific recommendations about setting up and implementing a sleep hygiene program for the dementia patient and training in behavior management skills. Patients in active treatment were also instructed to walk daily and increase daytime light exposure with the use of a light box. Control subjects (n=19) received general dementia education and caregiver support.
Primary sleep outcomes were derived for patients and caregivers from 1 week of sleep-wake activity measured at baseline, posttest (2 months), and 6-month follow-up using an Actillume wrist-movement recorder. Secondary patient outcomes included the Epworth Sleepiness Scale, the Cornell Depression Scale, and the Revised Memory and Behavior Problem Checklist. Caregiver self-reports included the Pittsburgh Sleep Quality Index and the Center for Epidemiological Study of Depression Scale.
Patients participating in NITE-AD showed significantly greater (P<.05) posttest reductions in number of nighttime awakenings, total time awake at night, and depression, and increases in weekly exercise days than control subjects. At 6-month follow-up, treatment gains were maintained, and additional significant improvements in duration of night awakenings emerged. When cognitive level was controlled, NITE-AD patients had lower longitudinal ratings of daytime sleepiness than controls. There was a trend for control subjects to spend more time in bed at 6 months than NITE-AD patients.
This study provides the first evidence that patients with AD who are experiencing sleep problems can benefit from behavioral techniques (specifically, sleep hygiene education, daily walking, and increased light exposure) that are known to improve sleep in nondemented, institutionalized older adults.
To analyze the effects of cognition on function and to explore the potential of aerobic exercise for promoting cognitive and functional capacities.
Integrative review of literature.
Studies were selected based on an extensive search of electronic databases and manual cross-referencing for 1980 to 2006, using the combination of key words: Alzheimer's disease (AD), dementia, or cognitive impairment with function or activities of daily living.
Three broad themes were identified from the literature analysis. First, global cognition has mainly been used to examine the effect of cognition on function, indicating an assumption that functional decline progresses in a hierarchical manner in AD. Second, specific cognitive domains affect functional decline in different ways. Executive functioning might have more effect on function than does memory. Third, aerobic exercise might promote cognitive and functional capacities in people with AD by modifying neuropathological changes in the brain.
Specific cognitive domains such as executive functioning are important for understanding function in people with AD and are potentially modifiable by aerobic exercise.
To investigate the effectiveness of an exercise program in improving ability to perform activities of daily living (ADLs), physical performance, and nutritional status and decreasing behavioral disturbance and depression in patients with Alzheimer's disease (AD).
Randomized, controlled trial.
Five nursing homes.
One hundred thirty-four ambulatory patients with mild to severe AD.
Collective exercise program (1 hour, twice weekly of walk, strength, balance, and flexibility training) or routine medical care for 12 months.
ADLs were assessed using the Katz Index of ADLs. Physical performance was evaluated using 6-meter walking speed, the get-up-and-go test, and the one-leg-balance test. Behavioral disturbance, depression, and nutritional status were evaluated using the Neuropsychiatric Inventory, the Montgomery and Asberg Depression Rating Scale, and the Mini-Nutritional Assessment. For each outcome measure, the mean change from baseline to 12 months was calculated using intention-to-treat analysis.
ADL mean change from baseline score for exercise program patients showed a slower decline than in patients receiving routine medical care (12-month mean treatment differences: ADL=0.39, P=.02). A significant difference between the groups in favor of the exercise program was observed for 6-meter walking speed at 12 months. No effect was observed for behavioral disturbance, depression, or nutritional assessment scores. In the intervention group, adherence to the program sessions in exploratory analysis predicted change in ability to perform ADLs. No adverse effects of exercise occurred.
A simple exercise program, 1 hour twice a week, led to significantly slower decline in ADL score in patients with AD living in a nursing home than routine medical care.
The purpose oF this study was to examine the eFFects oF 3 behavioral interventions on aFFect and mood in nursing home residents with Alzheimer's disease. In a pre-post design, 90 residents with Alzheimer's disease were randomized to 3 groups: supervised walking, comprehensive exercise (walking plus strength training, balance, and Flexibility exercises), and social conversation (casual rather than therapeutic themes). Interventions were provided 5 days a week and progressed up to 30 minutes per session over 16 weeks. Interventions were conducted primarily indoors. Outcome measures included the Lawton Observed AFFect Scale, Alzheimer Mood Scale, and Dementia Mood Assessment. At posttest, participants receiving comprehensive exercise exhibited higher positive and lower negative aFFect and mood. The social conversation group exhibited the least positive and most negative mood and aFFect. Results suggest that exercise programs be emphasized in long-term care, particularly whole-body involvement rather than walking alone.
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The purpose of this study was to compare the effects of 16 weeks of a comprehensive exercise routine to supervised walking and social conversation on depression in nursing home residents with Alzheimer's disease (AD).
Method:
This study was a three-group, repeated-measures design with random assignment to treatment group. Forty-five nursing home residents with moderate to severe AD were randomly assigned to a 16-week programme of comprehensive exercise, supervised walking or social conversation. Raters were blinded to treatment group assignment. Major outcome variables were depression measured by the Cornell Scale for Depression in Dementia, mood measured by the Dementia Mood Assessment Scale and the Alzheimer's Mood Scale, and affect measured by the Observed Affect Scale. Depression was reduced in all three groups with some evidence of superior benefit from exercise. Depression is a common problem with serious and costly consequences for nursing home residents with AD. Exercise as a behavioural approach to treatment of depression in nursing home residents with severe AD evidenced a clear benefit to participants in this study. More research is needed to clarify the relative benefits of different types of exercise in conjunction with or without pharmacological intervention.
The recent availability of longitudinal data on the possible association of different lifestyles with dementia and Alzheimer's disease (AD) allow some preliminary conclusions on this topic. This review systematically analyses the published longitudinal studies exploring the effect of social network, physical leisure, and non-physical activity on cognition and dementia and then summarises the current evidence taking into account the limitations of the studies and the biological plausibility. For all three lifestyle components (social, mental, and physical), a beneficial effect on cognition and a protective effect against dementia are suggested. The three components seem to have common pathways, rather than specific mechanisms, which might converge within three major aetiological hypotheses for dementia and AD: the cognitive reserve hypothesis, the vascular hypothesis, and the stress hypothesis. Taking into account the accumulated evidence and the biological plausibility of these hypotheses, we conclude that an active and socially integrated lifestyle in late life protects against dementia and AD. Further research is necessary to better define the mechanisms of these associations and better delineate preventive and therapeutic strategies.
Nearly 200 studies have examined the impact that either acute or long-term exercise has upon cognition. Subsets of these studies have been reviewed using the traditional narrative method, and the common conclusion has been that the results are mixed. Therefore, a more comprehensive review is needed that includes all available studies and that provides a more objective and reproducible review process. Thus, a meta-analytic review was conducted that included all relevant studies with sufficient information for the calculation of effect size (W = 134). The overall effect size was 0.25, suggesting that exercise has a small positive effect on cognition. Examination of the moderator variables indicated that characteristics related to the exercise paradigm, the participants, the cognitive tests, and the quality of the study influence effect size. However, the most important finding was that as experimental rigor decreased, effect size increased. Therefore, more studies need to be conducted that emphasize experimental rigor.
This article advocates proactive Alzheimer treatment, describes rehab interventions implemented by students, and reports positive first year outcomes for 11 mild to moderate Alzheimer's disease (AD) patients who experienced these interventions in a longitudinal Alzheimer rehabilitation research programme. Students supervised physical fitness training and volunteer work sessions for all participants and administered specific memory and language stimulation exercises to 7 of them (experimental group). Outcomes were measured by standardised and project-related tests before and after two semesters (about 28 weeks) of participation. It was hypothesised that (1) the experimental group would outperform the control group at post-testing on standardised and project-specific cognitive and language measures; that both the experimental and control group would (2) maintain or improve the quality of their spontaneous discourse, (3) improve on measures of mood, and (4) improve on measures of physical fitness. Hypothesis 1 was only partially supported. The experimental group improved significantly from pre- to post-test on two measures, substantially on one measure, and showed no change on eleven measures. The control group declined significantly on three measures and showed no change on eleven measures. However, between group differences were only significant on one measure. Hypotheses 2, 3, and 4 were supported. The major conclusion was that: multi-modal interventions by students can temporarily maintain or improve cognitive, language, social, and physical functioning of Alzheimer's patients.
The importance of physical activity to maintain a healthy psychological functions is widely known. The present study involved 15 males affected by senile dementia of Alzheimer type (SDAT) and assessed their functional capabilities by means of the following neuropsychological tests: test of attentional matrix, verbal span test, supraverbal span test, mini mental state examination. After an exercise training program of 3 months, patients were assessed again by the same psychological tests which demonstrated a significant improvement.
Older adults reap many health benefits from aerobic exercise training; however, little is known about how to monitor the training responses in older adults with Alzheimer's disease. The purpose of this pilot study was to examine the correlation of objectively measured heart rate and subjectively reported perceived exertion during aerobic exercise training in four older men with advanced Alzheimer's disease from a pilot study that used a one-group pre- and post-test design. During training (three times per week for 8 weeks), the participants' heart rate and perceived exertion were assessed by a trained exercise trainer every 5 min by using the Polar heart rate monitor and the Borg's Rating of Perceived Exertion Scale, respectively. There were 596 heart rate-perceived exertion data pairs. The results show that the Pearson's r for the heart rate and perceived exertion was 0.457 (significant at 0.01, two-tailed), controlling for age, education, exercise session, and cognition. We conclude that the Borg's Rating of Perceived Exertion Scale itself might be insufficient for monitoring the exercise responses in older men with advanced Alzheimer's disease. Future studies are needed to further examine the utility of this scale in this population.
Emerging science suggests that aerobic exercise might modify the pathophysiology of Alzheimer's disease (AD) and improve cognition. However, there are no clinical practice guidelines for aerobic exercise prescription and training in older adults with AD. A few existing studies showed that older adults with AD can participate in aerobic exercise and improve dementia symptoms, but lack adequate descriptions of their aerobic exercise training programs and their clinical applicability. In this paper, we summarize current knowledge about the potential benefits of aerobic exercise in older adults with AD. We then describe the development of a moderate-intensity aerobic exercise program for this population and report results from its initial testing in a feasibility trial completed by two persons with AD. Two older adults with AD completed the aerobic exercise program. Barriers to the program's implementation are described, and methods to improve more wide-spread adoption of such programs and the design of future studies that test them are suggested.
Although exercise has long been equated with better physical health, there is now extensive research showing that it has substantial benefits for the brain as well. From an Alzheimer's disease (AD) standpoint, one of the most important effects of exercise is on cognition. Exercise not only improves cognitive function in normal individuals, but it has been associated with a lower risk for AD and other types of dementia. Studies in animal models also suggest that exercise might attenuate some of the cognitive symptoms and pathophysiology of dementia. Recent research has attempted to identify molecular and cellular changes in the central nervous system elicited by physical activity. Work in animal models has identified several key responses, including up-regulation of growth factors, increased neurogenesis, and improved learning and memory, which might be key to improved cognition in response to exercise.
As the number of elderly persons in our country increases, more attention is being given to geriatric healthcare needs and successful ageing is becoming an important topic in medical literature. Concept of successful ageing is in first line on a preventive approach of care for older people. Promotion of regular physical activity is one of the main non-pharmaceutical measures proposed to older subjects as low rate of physical activity is frequently noticed in this age group. Moderate but regular physical activity is associated with a reduction in total mortality among older people, a positive effect on primary prevention of coronary heart disease and a significant benefit on the lipid profile. Improving body composition with a reduction in fat mass, reducing blood pressure and prevention of stroke, as well as type 2 diabetes, are also well established. Prevention of some cancers (especially that of breast and colon), increasing bone density and prevention of falls are also reported. Moreover, some longitudinal studies suggest that physical activity is linked to a reduced risk of developing dementia and Alzheimer's disease in particular.
To determine the feasibility and efficacy of a home-based exercise intervention program to improve the functional performance of patients with Alzheimer's Disease (AD).
Twenty-seven home-dwelling patients with AD were randomized to either an exercise intervention program delivered by their caregivers or a home safety assessment control. Measures of functional performance (primary), cognition, neuropsychiatric symptoms, quality of life and caregiver burden (secondary) were obtained at baseline and at 6 and 12 weeks following randomization. For each outcome measure, intent-to-treat analyses using linear random effects models were performed. Feasibility and adverse events were also assessed.
Adherence to the exercise program was good. On the primary outcomes (functional performance) patients in the exercise group demonstrated a trend for improved performance on measures of hand function and lower extremity strength. On secondary outcome measures, trends toward worse depression and lower quality of life ratings were noted.
The physical exercise intervention developed for the study, delivered by caregivers to home-dwelling patients with AD, was feasible and was associated with a trend for improved functional performance in this group of frail patients. Given the limited efficacy to date of pharmacotherapies for AD, further study of exercise intervention, in a variety of care setting, is warranted.
Physical activity delays loss of autonomy in the elderly. In patients with Alzheimer disease (AD), physical activity could be a useful strategy in therapeutic management by delaying loss of functional independence and the usual complications of the disease.
To determine, using standardized tools, the effects on autonomy (ADL, IADL), cognitive function (MMS), nutritional status (MNA), behavioral problems (NPI) and risk of falls (Tinetti test) of a physical exercise program in patients with AD.
Twenty-three subjects (13 men and 10 women, aged 71-92 years, mean 78 years) with AD (mean MMS 16, range 1-23) carried out for a mean of 7 weeks (5-12 weeks) a program of endurance exercise (walking, exercise bicycle) adapted to their individual capacities. Standardized gerontological evaluation was performed before and after the study.
No significant change in autonomy (ADL, IADL) was observed. There was an improvement in the MNA (p<0.001) and the MMS (p<0.001). Risk of falls (p<0.01) and behavioral problems (p<0.05) decreased. These results were obtained without increasing family workload.
We suggest that physical activity is a therapeutic option which can reduce nutritional and behavioral complications and risk of falls in subjects with AD.
Assisted walking and walking combined with conversation were compared to a conversation-only intervention in nursing home residents with Alzheimer disease. Sixty-five subjects randomly assigned to treatment group were tested at baseline and end of treatment. Subjects' mean Mini-Mental State Examination score was 10.83; mean age was 87. Treatment was given for 30 minutes three times a week for 16 weeks. Subjects in the assisted walking group declined 20.9% in functional mobility; the conversation group declined 18.8%. The combined walking and conversation treatment group declined only 2.5%. These differences in outcome were significant and appear to have been affected by differences in treatment fidelity. Subjects in the conversation treatment group completed 90% of intended treatment compared with 75% in the combined group and only 57% in the assisted walking group. Failure to treat was due to subject refusal and physical illness. The conversation component of the combined walking and conversation treatment intervention appears to have improved compliance with the intervention, thereby improving treatment outcome. Results indicate that assisted walking with conversation can contribute to maintenance of functional mobility in institutionalized populations with Alzheimer disease. Staff assigned to this task should be prepared to use effective communication strategies to gain acceptance of the intervention.
to determine the effects of aerobic training on the maximal aerobic power of healthy, very elderly people.
a 12-week control period followed by 24 weeks of progressive, weight bearing, aerobic training.
26 men and women aged 79 to 91 years conforming to pre-determined health criteria.
we took measurements before and after a 12 week control period and following 24 weeks of training. These were maximal aerobic power (VO(2)max), heart rate at an oxygen consumption of 10 ml x kg(-1) x min(-1) (HR at VO(2)10), resting heart rate, isometric knee extensor strength, isometric elbow flexor strength and lower limb extensor power.
pre-control values of VO(2)max for the women and men were 14.1 (SD 2.79) and 22.0 (5.12) ml.kg(-1).min(-1) respectively. There was no significant change in the VO(2)max of either group over the control period. After training, there was a 15% increase in the VO(2)max of the women (P<0.01) but no change was observed in the men. In the women, there was no significant change in HR at VO(2)10 over the control period but a 14% decrease (P<0.01) after training. In the men there was a 7% (P<0.05) increase in HR at VO(2)10 over the control period and a 5% (P<0.05) decrease after training. No effect of training was seen on isometric knee extensor strength, isometric elbow flexor strength or lower limb extensor power of either group.
progressive aerobic training can increase the maximal aerobic power of very elderly women. A 15% increase in VO(2)max may prevent many elderly women from crossing functionally important thresholds, thereby helping to maintain independence.
A meta-analytic study was conducted to examine the hypothesis that aerobic fitness training enhances the cognitive vitality of healthy but sedentary older adults. Eighteen intervention studies published between 1966 and 2001 were entered into the analysis. Several theoretically and practically important results were obtained. Most important fitness training was found to have robust but selective benefits for cognition, with the largest fitness-induced benefits occurring for executive-control processes. The magnitude of fitness effects on cognition was also moderated by a number of programmatic and methodological factors, including the length of the fitness-training intervention, the type of the intervention, the duration of training sessions, and the gender of the study participants. The results are discussed in terms of recent neuroscientific and psychological data that indicate cognitive and neural plasticity is maintained throughout the life span.
At a time when they are losing skills in virtually all arenas of life, persons with Alzheimer's disease can experience significant, esteem-building achievements in physical fitness and mood through supervised participation in an exercise program. The effects of physical exercise plus cognitive and social stimulation on persons with early stage Alzheimer's disease were assessed in a longitudinal study. Twenty-four such individuals, aged 54 to 88 at program entry, participated in 16 to 20 exercise sessions and 10 community activity sessions per semester for two to eight semesters. Half of the weekly exercise sessions included memory and language stimulation activities. Students, supplemented by family caregivers, supervised the sessions. Exercise sessions consisted of flexibility, balance, aerobic, and weight resistance activities. Preparticipation and semiannual post-testing of aerobic fitness and duration and upper and lower body strength was done.
Highly significant fitness gains (p < .001) were achieved in the six-minute walk test, upper and lower body strength, and duration of aerobic exercise. Five participants, aged 86 to 91, completed six to eight semesters and were doing 27 to 45 minutes of aerobics per session at program's end. Five participants scored within the normal range for age-matched healthy active adults on the sixminute walk test at baseline. Nine others achieved and three exceeded the normal range during treatment. Cognitive decline was slowed and mood improved. Firstyear cognitive outcomes have been published elsewhere. 1-4 An article reporting final cognitive outcomes is in preparation; Outcome data is summarized on the project website: www.u.arizona.edu/~sarkin/elderrehab.html.
The benefits of physical exercise can be made available at nominal cost to Alzheimer's patients and other elderly persons by using students to provide transportation, supervision, and the motivational support that is key to exercise adherence. Further research is needed to determine the relative contributions of each program component to the positive outcomes.
To determine whether cardiorespiratory fitness at baseline is associated with maintenance of cognitive function over 6 years or with level of cognitive function on tests performed 6 years later in a longitudinal study of healthy older people.
Prospective cohort.
Community-based study of noninstitutionalized adults aged 55 and older living in Sonoma, California.
Three hundred forty-nine cohort members without evidence of cardiovascular disease, musculoskeletal disability, or cognitive impairment at baseline.
Cardiorespiratory fitness measures were based on a standard treadmill exercise test protocol and included peak oxygen consumption (peak VO2), treadmill exercise duration, and oxygen uptake efficiency slope (OUES). Cognitive function was evaluated at baseline with a modified Mini-Mental State Examination (mMMSE) and after 6 years of follow-up with a detailed cognitive test battery that included the full MMSE, three tests of attention/executive function, two measures of verbal memory, and two tests of verbal fluency.
Participants with worse cardiorespiratory fitness at baseline experienced greater decline on the mMMSE over 6 years (mean mMMSE decline (95% confidence interval) by baseline peak VO2 tertile: lowest = -0.5 (-0.8 to -0.3), middle = -0.2 (-0.5-0.0), highest = 0.0 (-0.3-0.2), P =.002 for trend over tertiles). Participants with worse baseline cardiorespiratory fitness also performed worse on all cognitive tests conducted 6 years later. Results were similar for analyses based on peak VO2, treadmill exercise duration, and OUES. After adjustment for demographic and health-related covariates, measures of cardiorespiratory fitness were associated most strongly with measures of global cognitive function and attention/executive function.
Baseline measures of cardiorespiratory fitness are positively associated with preservation of cognitive function over a 6-year period and with levels of performance on cognitive tests conducted 6 years later in healthy older adults. High cardiorespiratory fitness may protect against cognitive dysfunction in older people.
Physical activity may help maintain cognitive function and decrease dementia risk, but epidemiological findings remain controversial. The aim of our study was to investigate the association between leisure-time physical activity at midlife and the subsequent development of dementia and Alzheimer's disease (AD).
Participants were randomly selected from the survivors of a population-based cohort previously surveyed in 1972, 1977, 1982, or 1987. 1449 persons (72.5%) age 65-79 years participated in the re-examination in 1998 (mean follow-up, 21 years). 117 persons had dementia and 76 had AD. Multiple logistic regression methods were used to analyse the association between leisure-time physical activity and dementia or AD.
Leisure-time physical activity at midlife at least twice a week was associated with a reduced risk of dementia and AD (odds ratio [OR] 0.48 [95% CI 0.25-0.91] and 0.38 [0.17-0.85], respectively), even after adjustments for age, sex, education, follow-up time, locomotor disorders, APOE genotype, vascular disorders, smoking, and alcohol drinking. The associations were more pronounced among the APOE epsilon4 carriers.
Leisure-time physical activity at midlife is associated with a decreased risk of dementia and AD later in life. Regular physical activity may reduce the risk or delay the onset of dementia and AD, especially among genetically susceptible individuals.
Many studies have been conducted to test the potentially beneficial effects of physical activity on cognition. The results of meta-analytic reviews of this literature suggest that there is a positive association between participation in physical activity and cognitive performance. The design of past research demonstrates the tacit assumption that changes in aerobic fitness contribute to the changes in cognitive performance. Therefore, the purpose of this meta-analysis was to use meta-regression techniques to statistically test the relationship between aerobic fitness and cognitive performance. Results indicated that there was not a significant linear or curvilinear relationship between fitness effect sizes (ESs) and cognitive ESs for studies using cross-sectional designs or posttest comparisons. However, there was a significant negative relationship between aerobic fitness and cognitive performance for pre-post comparisons. The effects for the cross-sectional and pre-post comparisons were moderated by the age group of the participants; however, the nature of this effect was not consistent for the two databases. Based on the findings of this meta-analytic review, it is concluded that the empirical literature does not support the cardiovascular fitness hypothesis. To confirm the findings of this review, future research should specifically test the dose-response relationship between aerobic fitness and cognitive performance. However, based upon the findings of this review, we also encourage future research to focus on other physiological and psychological variables that may serve to mediate the relationship between physical activity and cognitive performance.
Whereas aerobic capacity declines with age, major factors responsible for such decline have been poorly defined by past studies.
Participants were relatively healthy older individuals (339 women, 253 men) in whom demographic information and cardiopulmonary physiological measurements were obtained at baseline and biannually for three additional measurements.
The study identified progressive declines in both forced expiratory volume in 1 second (FEV(1)) and in maximal exercise heart rate as two variables that accounted primarily for the longitudinal decline of aerobic performance in this cohort of relatively fit older persons who achieved high respiratory exchange ratios (RER; mean = 1.08 for women, 1.12 for men). Whereas women achieved a peak oxygen consumption (VO(2peak)) only 77% that of men, oxygen uptake became similar to men (to 95%) when measured per kilogram of lean body mass rather than per kilogram of total body mass. During the 6 years of the study (four time points) aerobic capacity declined in both sexes, however, less steeply for women than for men (18% vs 24% per decade, respectively). The rate of decline was independent of baseline variables such as body composition (e.g., lean body mass, lean/fat ratio), smoking status, medications, or concomitant health conditions, even though these variables strongly influenced baseline aerobic performance. Inclusion of FEV(1) and maximal exercise heart rate into the statistical models, however, accounted for most of the longitudinal decline of aerobic performance. When adjusted for these two variables, aerobic capacity declined 9.7% and 10.4% per decade in women and men, respectively.
Our findings emphasize the primary importance of declining FEV(1) and declining maximal exercise heart rate in accounting for the "aging effect" on aerobic capacity. Thus, when comparing longitudinal studies, all estimates of aerobic decline should be interpreted with respect to the specific variables included in the models, which also need to include FEV(1) and maximal exercise heart rate.
Given the aging populations in many countries throughout the world, there is an increasing interest in lifestyle factors and interventions that will enhance the cognitive vitality of older adults and reduce the risk for age-related neurological disorders, such as Alzheimer's disease. In this review, we evaluate the hypothesis that physical activity and exercise might serve to protect, and also enhance, cognitive and brain function across the adult lifespan. To this end, we critically review three separate literatures that have examined the influence of physical activity and exercise on cognition, brain function and brain structure of adults, including epidemiological or prospective observational studies, randomized human clinical interventions and non-human animal studies. We suggest that this literature supports the claim that physical activity enhances cognitive and brain function, and protects against the development of neurodegenerative diseases. We discuss future directions to address currently unresolved questions, such as interactions between multiple lifestyle factors on offsetting or protecting against cognitive and neural decline, and conclude that physical activity is an inexpensive treatment that could have substantial preventative and restorative properties for cognitive and brain function.
To examine associations between functional capacity estimated from cardiorespiratory fitness (CRF) and mortality risks in adults aged 60 and older.
Prospective study, averaging 13.6 years follow-up.
Preventive medical clinic.
Four thousand sixty adults who completed preventive medical examinations between 1971 and 2001; 24.7% women, mean age+/-standard deviation 64.6+/-4.9, body mass index (BMI) 25.9+/-3.8 kg/m2.
CRF was quantified as metabolic equivalents (METs) achieved during maximal treadmill exercise. The lowest 20% of the age- and sex-specific MET distribution was defined as having low CRF, the middle 40% moderate CRF, and the upper 40% high CRF. Cox regression was used to estimate death rates (per 1,000 person-years), hazard ratios (HRs), and their 95% confidence intervals (CIs).
Nine hundred eighty-nine deaths occurred during follow-up. Death rates adjusted for age, sex, and examination year were 30.9, 18.3, and 13.4 for all causes (P<.001); 15.9, 8.6, and 5.4 for cardiovascular disease (CVD) (P<.001); and 6.1, 4.9, and 4.2 for cancer (P=.04) for subjects with low, moderate, and high CRF, respectively. After adjusting for smoking, abnormal electrocardiograms at rest or while exercising, percentage of age-predicted maximal heart rate achieved during exercise testing, baseline medical conditions, BMI, hypercholesterolemia, and family CVD and cancer history, subjects with high CRF had notably lower mortality risk than those with low CRF from all causes (HR=0.59, 95% CI=0.47-0.74) and from CVD (HR=0.57, 95% CI=0.41-0.80).
CRF is an important independent predictor of death in older adults. The results add to the existing evidence that promoting physical activity in older adults provides substantial health benefits, even in the oldest old.
To examine the hypothesis that changes in self-efficacy and functional performance mediate, in part, the beneficial effect of physical activity on functional limitations over time.
Prospective, observational study.
Community-based.
Two hundred forty-nine community-dwelling older women.
Participants completed measures of self-reported physical activity, functional limitations, and self-efficacy. Four measures of physical function performance were also assessed. Measures were completed at baseline and 24 months. Data were analyzed using a panel model within a covariance modeling framework.
Results indicated that increases in physical activity over time were associated with greater improvements in self-efficacy, which was associated in turn with improved physical function performance, both of which mediated the association between physical activity and functional limitations. Fewer functional limitations at baseline were also associated with higher levels of self-efficacy at 24 months. Age, race, and health status covariates did not significantly change these relationships.
The findings support the mediating roles of self-efficacy and physical function performance in the relationship between longitudinal changes in physical activity and functional limitations in older women.
There is an increasing interest in exercise and fitness in Alzheimer disease (AD) given evidence suggesting a role in the maintenance of cognitive health. There is, however, little data on the objective measure of cardiorespiratory fitness in individuals with AD. Thus, we assessed cardiorespiratory fitness in early AD and its relationship with physical activity levels, health markers, and cognitive performance in nondemented (Clinical Dementia Rating 0, n=31) and early-stage AD (Clinical Dementia Rating 0.5 and 1, n=31) participants. Cardiorespiratory fitness was assessed with maximal exercise testing to determine peak oxygen consumption (VOpeak2). Additionally, dual emission x-ray absorptiometry scanning for body composition and glucose tolerance tests were conducted. Despite reductions in physical performance and habitual physical activity levels in early AD, cardiorespiratory fitness (VOpeak2) was comparable in the 2 groups (19.8 in early AD vs. 21.2 mL/kg/min in nondemented, P=0.26). AD participants performed well on treadmill tests with similar levels of perceived exertion, maximal heart rate, and respiratory exchange ratio compared with nondemented individuals. After controlling for age and sex, VOpeak2 was associated with a beneficial glucoregulatory profile and inversely associated with percent body fat, body mass index, and triglycerides. A relationship between cognitive performance measures and VOpeak2 was not apparent. These results suggest that individuals in the early stages of AD have the capacity for maximal exercise testing and have comparable levels of cardiorespiratory fitness as nondemented individuals. Reduced physical activity associated with early AD underscores the need for further defining the role of exercise as a potential therapeutic intervention in the early stages of AD.
Physical activity and enhanced fitness to improve cognitive function in older people without known cognitive impairment. Physical activity is beneficial for healthy ageing. It may also help maintain good cognitive function in older age. Aerobic activity improves cardiovascular fitness, but it is not known whether this sort of fitness is necessary for improved cognitive function. Eleven studies of aerobic physical activity programmes for healthy people over the age of 55 years have been included in this review. Eight of these 11 studies reported that aerobic exercise interventions resulted in increased fitness of the trained group and an improvement in at least one aspect of cognitive function. The largest effects were on cognitive speed, delayed memory functions, auditory and visual attention. However, the cognitive functions which improved were not the same in each study and the majority of comparisons yielded no significant results. The data are insufficient to show that the improvements in cognitive function which can be attributed to physical exercise are due to improvements in cardiovascular fitness.
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