Article

Mediation of Cognitive Function Improvements by Strength Gains After Resistance Training in Older Adults with Mild Cognitive Impairment: Outcomes of the Study of Mental and Resistance Training

October 2016
Journal of the American Geriatrics Society 65(3)

DOI:10.1111/jgs.14542

Authors:

Yorgi Mavros

The University of Sydney

Nicola J Gates

UNSW Sydney

Guy Charles Wilson

The University of Sydney

Nidhi Jain

The University of Sydney

Show all 16 authorsHide

Objectives: To determine whether improvements in aerobic capacity (VO2peak ) and strength after progressive resistance training (PRT) mediate improvements in cognitive function. Design: Randomized, double-blind, double-sham, controlled trial. Setting: University research facility. Participants: Community-dwelling older adults (aged ≥55) with mild cognitive impairment (MCI) (N = 100). Intervention: PRT and cognitive training (CT), 2 to 3 days per week for 6 months. Measurements: Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-Cog); global, executive, and memory domains; peak strength (1 repetition maximum); and VO2peak . Results: PRT increased upper (standardized mean difference (SMD) = 0.69, 95% confidence interval = 0.47, 0.91), lower (SMD = 0.94, 95% CI = 0.69-1.20) and whole-body (SMD = 0.84, 95% CI = 0.62-1.05) strength and percentage change in VO2peak (8.0%, 95% CI = 2.2-13.8) significantly more than sham exercise. Higher strength scores, but not greater VO2peak , were significantly associated with improvements in cognition (P < .05). Greater lower body strength significantly mediated the effect of PRT on ADAS-Cog improvements (indirect effect: β = -0.64, 95% CI = -1.38 to -0.004; direct effect: β = -0.37, 95% CI = -1.51-0.78) and global domain (indirect effect: β = 0.12, 95% CI = 0.02-0.22; direct effect: β = -0.003, 95% CI = -0.17-0.16) but not for executive domain (indirect effect: β = 0.11, 95% CI = -0.04-0.26; direct effect: β = 0.03, 95% CI = -0.17-0.23). Conclusion: High-intensity PRT results in significant improvements in cognitive function, muscle strength, and aerobic capacity in older adults with MCI. Strength gains, but not aerobic capacity changes, mediate the cognitive benefits of PRT. Future investigations are warranted to determine the physiological mechanisms linking strength gains and cognitive benefits.

Global consensus on optimal exercise recommendations for enhancing healthy longevity in older adults (ICFSR)

Article

Full-text available

Jan 2025
J NUTR HEALTH AGING

Aging, a universal and inevitable process, is characterized by a progressive accumulation of physiological alterations and functional decline over time, leading to increased vulnerability to diseases and ultimately mortality as age advances. Lifestyle factors, notably physical activity (PA) and exercise, significantly modulate aging phenotypes. Physical activity and exercise can prevent or ameliorate lifestyle-related diseases, extend health span, enhance physical function, and reduce the burden of non-communicable chronic diseases including cardiometabolic disease, cancer, musculoskeletal and neurological conditions, and chronic respiratory diseases as well as premature mortality. Physical activity influences the cellular and molecular drivers of biological aging, slowing aging rates—a foundational aspect of geroscience. Thus, PA serves both as preventive medicine and therapeutic agent in pathological states. Sub-optimal PA levels correlate with increased disease prevalence in aging populations. Structured exercise prescriptions should therefore be customized and monitored like any other medical treatment, considering the dose-response relationships and specific adaptations necessary for intended outcomes. Current guidelines recommend a multifaceted exercise regimen that includes aerobic, resistance, balance, and flexibility training through structured and incidental (integrated lifestyle) activities. Tailored exercise programs have proven effective in helping older adults maintain their functional capacities, extending their health span, and enhancing their quality of life. Particularly important are anabolic exercises, such as Progressive resistance training (PRT), which are indispensable for maintaining or improving functional capacity in older adults, particularly those with frailty, sarcopenia or osteoporosis, or those hospitalized or in residential aged care. Multicomponent exercise interventions that include cognitive tasks significantly enhance the hallmarks of frailty (low body mass, strength, mobility, PA level, and energy) and cognitive function, thus preventing falls and optimizing functional capacity during aging. Importantly, PA/exercise displays dose-response characteristics and varies between individuals, necessitating personalized modalities tailored to specific medical conditions. Precision in exercise prescriptions remains a significant area of further research, given the global impact of aging and broad effects of PA. Economic analyses underscore the cost benefits of exercise programs, justifying broader integration into health care for older adults. However, despite these benefits, exercise is far from fully integrated into medical practice for older people. Many healthcare professionals, including geriatricians, need more training to incorporate exercise directly into patient care, whether in settings including hospitals, outpatient clinics, or residential care. Education about the use of exercise as isolated or adjunctive treatment for geriatric syndromes and chronic diseases would do much to ease the problems of polypharmacy and widespread prescription of potentially inappropriate medications. This intersection of prescriptive practices and PA/exercise offers a promising approach to enhance the well-being of older adults. An integrated strategy that combines exercise prescriptions with pharmacotherapy would optimize the vitality and functional independence of older people whilst minimizing adverse drug reactions. This consensus provides the rationale for the integration of PA into health promotion, disease prevention, and management strategies for older adults. Guidelines are included for specific modalities and dosages of exercise with proven efficacy in randomized controlled trials. Descriptions of the beneficial physiological changes, attenuation of aging phenotypes, and role of exercise in chronic disease and disability management in older adults are provided. The use of exercise in cardiometabolic disease, cancer, musculoskeletal conditions, frailty, sarcopenia, and neuropsychological health is emphasized. Recommendations to bridge existing knowledge and implementation gaps and fully integrate PA into the mainstream of geriatric care are provided. Particular attention is paid to the need for personalized medicine as it applies to exercise and geroscience, given the inter-individual variability in adaptation to exercise demonstrated in older adult cohorts. Overall, this consensus provides a foundation for applying and extending the current knowledge base of exercise as medicine for an aging population to optimize health span and quality of life.

Identifying exercise and cognitive intervention parameters to optimize executive function in older adults with mild cognitive impairment and dementia: a systematic review and meta-analyses of randomized controlled trials

Article

Full-text available

Aug 2024
EUR REV AGING PHYS A

Physical exercise is recognized for its beneficial effects on brain health and executive function, particularly through the careful manipulation of key exercise parameters, including type, intensity, and duration. The aim of this systematic review and meta-analysis was to delineate the optimal types, intensities, and durations of exercise that improve cognitive functions in older adults with mild cognitive impairment (MCI) or dementia. A comprehensive search was conducted in Scopus, Web of Science, and PubMed from their inception until December 2023. The methodological quality and publication bias of the included studies were assessed using the PEDro scale and Egger’s regression test, respectively. Separate meta-analyses were performed to assess the overall impact of exercise on cognitive assessments and to explore the effects of different exercise types (i.e., aerobic, resistance, dual-task, mind-body, and multi-component exercises) and intensities (i.e., low, moderate, and high) on executive function. Results were presented as standardized mean differences (SMD) and 95% confidence intervals (95% CI). A meta-regression analysis was conducted to examine the correlation between exercise duration and mean effects. In total, 15,087 articles were retrieved from three databases, of which 35 studies were included in our final analyses. The results indicated high overall methodological quality (PEDro score = 8) but a potential for publication bias (t = 2.08, p = 0.045). Meta-analyses revealed that all types of exercise (SMD = 0.691, CI [0.498 to 0.885], p < 0.001) and intensities (SMD = 0.694, CI [0.485 to 0.903], p < 0.001) show significant effects favoring exercise. Notably, dual-task exercises (SMD = 1.136, CI [0.236 to 2.035], p < 0.001) and moderate-intensity exercises (SMD = 0.876, CI [0.533 to 1.219], p < 0.001) exhibited the greatest effect. No significant correlation was observed between exercise duration and SMD (R² = 0.038, p = 0.313). Overall, our meta-analyses support the role of physical exercise in enhancing executive function in older adults with MCI or dementia. It is essential to carefully tailor exercise parameters, particularly type and intensity, to meet the specific needs of older adults with MCI or dementia. Such customization is crucial for optimizing executive function outcomes and improving overall brain health.

The Efficacy of Cognitive Training on Neuropsychological Outcomes in Mild Cognitive Impairment: A Meta-Analysis

Article

Full-text available

Oct 2023
BSRCCS

Mild cognitive impairment (MCI) or mild neurocognitive disorder is an intermediate stage of cognitive impairment between normal cognitive aging and dementia. Given the absence of effective pharmacological treatments for MCI, increasing numbers of studies are attempting to understand how cognitive training (CT) could benefit MCI. This meta-analysis aims to update and assess the efficacy of CT on specific neuropsychological test performance (global cognitive functioning, short-term verbal memory, long-term verbal memory, generativity, working memory, and visuospatial abilities) in individuals diagnosed with MCI, as compared to MCI control groups. After searching electronic databases for randomized controlled trials, 31 studies were found including 2496 participants. Results showed that CT significantly improved global cognitive functioning, short-term and long-term verbal memory, generativity, working memory, and visuospatial abilities. However, no significant effects were observed for shifting, abstraction ability/concept formation, processing speed, and language. The mode of CT had a moderating effect on abstraction ability/concept formation. The findings provide specific insights into the cognitive functions influenced by CT and guide the development of tailored interventions for MCI. While CT holds promise, further research is needed to address certain cognitive deficits and assess long-term effects on dementia progression.

Effect of Resistance Exercise Orders on Health Parameters in Trained Older Women: A Randomized Crossover Trial

Article

Sep 2022

Effect of Resistance Exercise Orders on Health Parameters in Trained Older Women: A Randomized Crossover Trial

Article

Aug 2022

Purpose: To compare the effects of four resistance exercise orders on muscular strength, body composition, functional fitness, cardiovascular risk factors, and mental health parameters in trained older women. Methods: The intervention lasted 63 weeks. Sixty-one physically independent women (> 60 years) after completing a 12-week resistance training (RT) pre-conditioning phase were randomized into four different exercise orders groups to perform 12 weeks of RT: multi- to single-joint and upper- to lower-body (MJ-SJ-U), single- to multi-joint and upper- to lower-body (SJ-MJ-U), multi- to single-joint and lower- to upper-body (MJ-SJ-L), and single- to multi-joint and lower- to upper-body (SJ-MJ-L). This was followed by a 12-week detraining period and another 12-week RT in which exercise orders were crossed-over between MJ-SJ and SJ-MJ conditions. Body composition (DXA), muscular strength (1RM tests), functional fitness (gait speed, walking agility, 30-s chair stand, and 6-min walk tests), cardiovascular risk factors (glucose, triglycerides, total cholesterol, LDL-c, HDL-c, C-reactive protein, AOPP, TRAP, and NOx), depressive (GDS-scale), and anxiety symptoms (BAI), cognitive performance (MoCA, Trail Making, verbal fluency, and Stroop test) were analyzed. Results: Following the final training period, all groups presented significant improvements (P < 0.05) in almost all analyzed variables (muscular strength, body composition, functional tests, blood biomarkers, and mental health parameters), without significant difference among exercise orders. Conclusions: Our results suggest that RT exercise orders in which MJ, SJ, upper, or lower-body exercises are performed first have similar effects on health parameters in trained older women.

Effect of High Intensity Power Training on Cognitive Function in Older Adults with Type 2 Diabetes: Secondary Outcomes of the GREAT2DO Study

Article

Full-text available

Apr 2022

We sought to determine the effects of 12 months of power training on cognition, and whether improvements in body composition, muscle strength and/or aerobic capacity (VO2peak) were associated with improvements in cognition in older adults with type 2 diabetes (T2D). Participants with T2D were randomized to power training or low intensity sham exercise control condition, three days per week for 12 months. Cognitive outcomes included memory, attention/speed, executive function, and global cognition. Other relevant outcomes included VO2peak, strength, and whole body and regional body composition. One hundred and three adults with T2D (mean age 67.9 years; SD 5.9; 50.5% women) were enrolled and analyzed. Unexpectedly, there was a nearly significant improvement in global cognition (P=0.05) in the sham group relative to power training, although both groups improved over time (P<0.01). There were significant interactions between group allocation and body composition or muscle strength in the models predicting cognitive changes. Therefore, after stratifying by group allocation, improvements in immediate memory were associated with increases in relative skeletal muscle mass (r=0.38, P=0.03), reductions in relative body fat (r=–0.40, P=0.02), and increases in knee extension strength were directly related to changes in executive function (r=–0.41, P=0.02) within the power training group. None of these relationships were present in the sham group (P>0.05). Although power training did not significantly improve cognition compared to low-intensity exercise control, improvements in cognitive function in older adults were associated with hypothesized improvements in body composition and strength after power training.

Resistance training protects the hippocampus and precuneus against atrophy and benefits white matter integrity in older adults with mild cognitive impairment

Article

Jan 2025

Mild cognitive impairment (MCI) refers to cognitive alterations with preservation of functionality. Individuals with this diagnosis have a higher risk of developing dementia. Non-pharmacological interventions, such as physical exercise, are beneficial for the cognition of this population. However, the impact of resistance training (RT) on the brain anatomy of older adults with MCI has not yet been clarified. This study aimed to investigate the effects of RT on cognition and brain anatomy in MCI. Forty-four older adults with MCI, 22 in the training group and 22 in the control group, were evaluated in neuropsychological tests and magnetic resonance imaging at the beginning and end of the study, which lasted 24 weeks. We used repeated measures ANOVA. The training group showed better performance in verbal episodic memory after intervention. The control group showed a decrease in gray matter volume in the hippocampus and precuneus, while the training group showed no reduction in the right hippocampus and precuneus. However, it showed a decrease in the volume of these regions on the left side and in the left superior frontal gyrus. In the analysis of white matter integrity, fractional anisotropy increased in the training group and decreased in the control group. Axial diffusivity decreased in the training group, while radial diffusivity increased in the control group, and mean diffusivity varied according to the tract evaluated. RT improves memory performance, positively influences white matter integrity parameters, and plays a protective role against atrophy of the hippocampus and precuneus in MCI.

The Effects of Exercise on Synaptic Plasticity in Individuals With Mild Cognitive Impairment: Protocol for a Pilot Intervention Study

Article

Full-text available

Oct 2023

Background Mild cognitive impairment (MCI) is a syndrome preceding more severe impairment characterized by dementia. MCI affects an estimated 15% to 20% of people older than 65 years. Nonpharmacological interventions including exercise are recommended as part of overall MCI management based on the positive effects of exercise on cognitive performance. Interval training involves brief intermittent bouts of exercise interspersed with short recovery periods. This type of exercise promotes cognitive improvement and can be performed in individuals with MCI. Synaptic plasticity can be assessed in vivo by the neurophysiological response to repetitive transcranial magnetic stimulation (rTMS). A method to assess synaptic plasticity uses an intermittent theta burst stimulation (iTBS), which is a patterned form of rTMS. Individuals with MCI have decreased responses to iTBS, reflecting reduced synaptic plasticity. It is unknown whether interval training causes changes in synaptic plasticity in individuals living with MCI. Objective This research will determine whether interval training performed using a cycle ergometer enhances synaptic plasticity in individuals with MCI. The three aims are to (1) quantify synaptic plasticity after interval training performed at a self-determined intensity in individuals with MCI; (2) determine whether changes in synaptic plasticity correlate with changes in serum brain-derived neurotrophic factor, osteocalcin, and cognition; and (3) assess participant compliance to the exercise schedule. Methods 24 individuals diagnosed with MCI will be recruited for assignment to 1 of the 2 equally sized groups: exercise and no exercise. The exercise group will perform exercise 3 times per week for 4 weeks. Synaptic plasticity will be measured before and following the 4-week intervention. At these time points, synaptic plasticity will be measured as the response to single-pulse TMS, reflected as the percent change in the average amplitude of 20 motor-evoked potentials before and after an iTBS rTMS protocol, which is used to induce synaptic plasticity. In addition, individuals will complete a battery of cognitive assessments and provide a blood sample from the antecubital vein to determine serum brain-derived neurotrophic factor and osteocalcin. Results The study began in September 2023. Conclusions The proposed research is the first to assess whether synaptic plasticity is enhanced after exercise training in individuals with MCI. If exercise does indeed modify synaptic plasticity, this will create a new avenue by which we can study and manipulate neural plasticity in these individuals. Trial Registration ClinicalTrials.gov NCT05663918; https://clinicaltrials.gov/study/NCT05663918 International Registered Report Identifier (IRRID) PRR1-10.2196/50030

High-velocity resistance training improves executive function in mobility-limited older adults

Article

May 2023
ARCH GERONTOL GERIAT

Objectives: To examine the effect of high-velocity resistance training (HVRT) on the executive function of middle-aged and older adults with and without mobility limitations. Methods: Participants (n = 41, female: 48.9%) completed a supervised 12-week HVRT intervention (2 sessions/week; at 40-60% of one-repetition maximum). The sample included 17 middle-aged adults (40-55 years); 16 older adults (>60 years) and 8 mobility-limited older adults (LIM). Executive function was assessed before and after the intervention period and was reported as z-scores. Maximal dynamic strength, peak power, quadriceps muscle thickness, maximal isometric voluntary contraction (MVIC), and functional performance were also measured pre and post intervention. Training-related adaptations in cognitive measures were calculated using a Generalized Estimating Equation model. Results: HVRT improved executive function in LIM (adjusted marginal mean differences [AMMD]: 0.21; 95%CI: 0.04, 0.38; p = 0.040) although no effect on middle-aged (AMMD: 0.04; 95%CI: -0.09; 0.17; p = 0.533) and older (AMMD: -0.11; 95%CI: -0.25; 0.02; p = 0.107) participants was observed. Improvements in maximal dynamic strength, peak power, MVIC, quadriceps muscle thickness, and functional performance were all associated with changes in executive function, and changes in the first four also seem to mediate the association between changes in functional performance and executive function. Conclusions: HVRT-induced improvement in executive function of mobility-limited older adults were mediated by changes in lower-body muscle strength, power, and muscle thickness. Our findings reinforce the relevance of muscle-strengthening exercises to preserve cognition and mobility in older adults.

Effects of Sitting Callisthenic Balance and Resistance Exercise Programs on Cognitive Function in Older Participants

Article

Full-text available

Nov 2022
Int J Environ Res Publ Health

Background: Exercise training programs have the potential to improve cognitive function in older subjects. However, the majority of training programs are based on aerobic modality. In the current study, the influence of 3 months programs of sitting callisthenic balance (SCB) and resistance training (RT) on cognitive functioning and the mediating role that a change in the level of neurotrophic factors and strength in older, healthy participants plays were examined. Material and methods: Global cognitive function was examined using MoCA, short-term memory using Digit Span and Delayed Matching to Sample, set shifting using Trial Making Test Part B, speed of processing simple visual stimuli using Simple Reaction Time, decision making using Choice Reaction Time, visual attention with Visual Attention Test (VAT), tests. Strength of lower and upper limbs, neurotrophin level (irisin, brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3), neurotrophin 4/5 (NT 4/5) were examined. Results: Improved scores in RT vs. SCB were noted in MoCA (p = 0.02), reaction time in SRT (p = 0.02), TMT B (p = 0.03), errors committed in CRT (p = 0.04) and VAT (p = 0.02) were observed. No significant changes in the level of neurotrophic factors were observed. Changes in upper limb strength were related to changes in the number of errors committed in the SRT (p = 0.03). Lower limb strength changes explained the dynamics of the number of correct answers (p = 0.002) and errors committed (p = 0.006) in VAT. Conclusions: Both SCB and RT influenced multiple cognitive domains. The RT program improved global cognitive functioning, while no improvement was noticed in the SCB group. Decision making, visual attention and global cognitive function were improved after the RT program. Set-shifting, short-term visual memory processing speed of simple visual stimuli were improved after the SCB program, while a decrease in the processing speed of simple visual stimuli was noted in the RT group. Changes in irisin were related to set-shifting and short-term memory, while in BDNF to an improvement in the processing speed of simple visual stimuli. Resistance exercise training programs could be applied to prevent age related declines of cognitive function in healthy older subjects.

Clinical Medicine Dynapenia and Low Cognition: A Cross-Sectional Association in Postmenopausal Women

Article

Jan 2021

Citation: Pasco, J.A.; Stuart, A.L.; Sui, S.X.; Holloway-Kew, K.L.; Hyde, N.K.; Tembo, M.C.; Rufus-Membere, P.; Kotowicz, M.A.; Williams, L.J. Dynapenia and Low Cognition: A Cross-Sectional Association in Postmenopausal Women.

Effect of High Intensity Power Training on Cognitive Function in Older Adults with Type 2 Diabetes: Secondary Outcomes of the GREAT2DO Study

Article

Full-text available

Apr 2022
J GERONTOL A-BIOL

A c c e p t e d M a n u s c r i p t We sought to determine the effects of 12 months of power training on cognition, and whether improvements in body composition, muscle strength and/or aerobic capacity (VO 2peak) were associated with improvements in cognition in older adults with type 2 diabetes (T2D). Participants with T2D were randomized to power training or low intensity sham exercise control condition, three days per week for 12 months. Cognitive outcomes included memory, attention/speed, executive function, and global cognition. Other relevant outcomes included VO 2peak , strength, and whole body and regional body composition. One hundred and three adults with T2D (mean age 67.9 years; SD 5.9; 50.5% women) were enrolled and analyzed. Unexpectedly, there was a nearly significant improvement in global cognition (P=0.05) in the sham group relative to power training, although both groups improved over time (P<0.01). There were significant interactions between group allocation and body composition or muscle strength in the models predicting cognitive changes. Therefore, after stratifying by group allocation, improvements in immediate memory were associated with increases in relative skeletal muscle mass (r=0.38, P=0.03), reductions in relative body fat (r=-0.40, P=0.02), and increases in knee extension strength were directly related to changes in executive function (r=-0.41, P=0.02) within the power training group. None of these relationships were present in the sham group (P>0.05). Although power training did not significantly improve cognition compared to low-intensity exercise control, improvements in cognitive function in older adults were associated with hypothesized improvements in body composition and strength after power training. Abstract Keywords: power training, cognition, type 2 diabetes

Principais estratégias de treinamento para pessoas idosas portadoras de doença de Alzheimer: estudo de revisão

Article

Full-text available

Jan 2025

Igor Gomes

A doença de Alzheimer (DA) é a etiologia mais comum entre as demências, correspondendo a 60% dos quadros demenciais e tende a se intensificar com o envelhecimento populacional. A prática de exercício físico proporciona efeitos benéficos a um grande número de agravos relacionados à DA. Além disso, a prática de exercício físico tem efeitos anti-inflamatórios e antioxidantes e menos efeitos colaterais do que os medicamentos. Muitos estudos recomendam seu uso do exercício no tratamento da DA, dada a crescente evidência para apoiar seus efeitos positivos na saúde mental, doenças neurodegenerativas e demências. No entanto, profissionais do movimento precisam estar atualizados sobre as estratégias de treinamento mais efetivas e eficazes para essa população. Dessa forma, o objetivo desse estudo de revisão foi refletir, baseado em evidências científicas, os efeitos das principais estratégias de treinamento (aeróbio, resistido e multicomponente) para pessoas portadoras de DA. Entre as estratégias de treinamento apresentadas, o treinamento multicomponente foi o que apresentou maior respaldo na literatura para melhora de aspectos relacionado a DA, além de melhora na qualidade de vida e depressão, sendo institucionalizadas ou não.

A meta-analysis of the efficacy of physical exercise interventions on activities of daily living in patients with Alzheimer's disease

Article

Full-text available

Nov 2024

Objective This study aimed to systematically review published randomized controlled trials on the effects of physical exercise on activities of daily living (ADL) in Alzheimer's patients through meta-analysis, thereby synthesizing existing evidence to provide scientific intervention recommendations for exercise prescriptions in Alzheimer's patients. Methods Based on strict literature inclusion and exclusion criteria, a systematic search was conducted in databases including PubMed and Web of Science from their inception to July 1, 2024. The Cochrane risk assessment tool was used to evaluate the design of randomized controlled trials. Studies reporting on physical exercise interventions for ADL in Alzheimer's patients were systematically identified. Subgroup analyses and meta-regression were performed to explore sources of heterogeneity. Results Nineteen articles, for analysis, providing 27 randomized controlled trials (RCTs). A random-effects model was used to calculate the effect size and 95% confidence interval for each independent study, and meta-analysis was performed using Stata 16.0 and RevMan 5.4 software. The results showed that physical exercise might significantly improve ADL in Alzheimer's patients (SMD = 0.33, 95% CI: 0.12–0.54, I² = 81.7%). Sensitivity analysis confirmed the robustness of the results (p > 0.05). Egger's test did not reveal significant publication bias (p = 0.145). Samples were divided into different subgroups based on intervention content, duration, frequency, and session length. Subgroup analysis based on intervention characteristics showed that resistance training or aerobic exercise (SMD = 0.83, 95% CI: 0.60–1.05), long-term interventions (>6 months, SMD = 0.31, 95% CI: 0.13–0.49), medium-frequency interventions (4-5 times per week, SMD=0.39, 95% CI: 0.23-0.55), and short-duration training ( ≤ 30 min, SMD = 0.96, 95% CI: 0.71–1.21) might be most effective in enhancing ADL in Alzheimer's patients. These improvements were not only statistically significant but also had substantial impact in clinical practice. Conclusion Resistance training or aerobic exercise lasting more than 6 months, 4–5 times per week, and lasting no more than 30 min per session may be most effective in improving ADLs in patients with Alzheimer's disease.

Effectiveness of resistance training on resilience in Hong Kong Chinese older adults

Article

Full-text available

Nov 2024

Resilience is regarded as a psychological variable facilitating successful and positive aging. Combined with active aging, mind-body intervention and aerobic exercises have been frequently examined to determine their capacity to promote active and successful aging. In this study, three groups of older adults participated in a 16-week intervention, with resistance training and Tai Chi as the active control group. The effects on resilience, functional fitness, and quality of life were measured immediately after the intervention and 12 weeks later. Results (n = 141)indicated that resistance training participants had significant differences in upper limb muscular strength and endurance, flexibility, and fat percentage while Tai Chi participants showed improvement in lower limb muscles and aerobic ability. Both groups significantly reduced BMI and significant differences in the within-subject effect. Moreover, participants only showed a significant between-group effect on muscle strength, aerobic endurance, and dynamic balance in the pre-test versus the post-test. Results indicated a prominent level of positive and self-related successful aging among participants, thus indicating that other factors impacted less on their level of resilience and health-related quality of life. However, the research outcomes still demonstrate the better effect of Tai Chi on older adults’ psychological outcomes. It can also be expected that other self-related factors might have affected the effect of resistance training. Trial registration: The trial was registered at ClinicalTrials.gov PRS (Trial ID: NCT04690465; date first posted: 30/12/2020).

Comparison of resistance training combined with breathing retraining, or alone, on cardiovascular risk factors, pulmonary function, circulatory parameters, and aerobic capacity in overweight young women: randomized and controlled trial

Preprint

Full-text available

Aug 2024

Background: To investigate the effects of resistance training with breathing retraining on body composition, pulmonary function, circulatory parameters, and aerobic capacity in overweight young women. Methods: 24 overweight young females were randomly allocated into the resistance training group (RT) and the resistance training combined with breathing retraining group (RT+B), and performed exercise training for eight weeks, three sessions/week and 60 minutes/session. 12 age and BMI matched but not overweight young females were also recruited as the control group (C). The variables of anthropometric, body composition, pulmonary and circulatory function, aerobic capacity, blood glucose and lipid profile were measured before and after the intervention. Results: Significant decreases in BMI, total body fat, TG and LDL-c were observed in the two exercise groups (p＜0.05). In both exercise groups, significant increases in VO2max were accompanied by noticeable increases in VC, FVC, MVV, FEV1, PEF and decreases in SBP, DBP, SBP2, cSBP, rAI (p＜0.05). The Group RT+B had significantly higher increases in VO2max, AT, and oxygen pulse level than those of the control and Group RT (p＜0.05). Conclusions: The combined resistance exercise and breathing retraining appears to be more effective than resistance exercise alone in improving pulmonary function and aerobic capacity in overweight young women.

Impact of resistance training in patients with intellectual disabilities: a systematic review and meta-analysis

Article

Full-text available

Jan 2024

Objective: This study reviews the effects of resistance training (RT) and combined exercises on adults with intellectual disabilities (ID), focusing on muscular strength improvements. Methodology: Databases including PubMed, Cochrane Library, Scopus, and Web of Science were searched until August, selecting studies that compared RT and combined exercises against control groups. Results: A total of 24 studies with 924 participants were analyzed. RT significantly improved body weight (mean difference [MD] = -1.05, p=0.01) and leg press-RM outcomes (MD = 12.86, p<0.0001) versus controls. Combined exercises also showed notable benefits, enhancing overall training effects (MD = 21.95, p=0.0006) and sit-to-stand performance (MD = 3.10, p=0.0003). Conclusion: RT and combined exercises significantly benefit body composition, flexibility, muscular strength, and cardiorespiratory fitness in individuals with ID. Customizing exercise programs based on individual needs, considering age, ID severity, and preferences, is vital.

A Challenge of Inactivity After the COVID-19 Pandemic: What Can We Learn from Australia?

Article

Full-text available

Mar 2024

This article discusses the importance of resuming exercise and physical activity (PA) post-COVID-19 pandemic, drawing insights from Australia's experience as a reference point. In Australia, accredited exercise physiologists (AEP) collaboratively work within their health sectors, employing evidence-based guidelines to assist individuals in safely resuming PA and exercise. Based on the latest guideline from Exercise and Sports Science Australia (ESSA) for AEP, tailored for post-pandemic PA resumption, the article summarizes what exercise professionals could do during this period in the wake of COVID-19 disruptions. Using China as a focal example, the article further explores potential interventions and approaches from both public health and clinical perspectives. The discourse concludes by emphasizing the worldwide-recognized importance of establishing regulatory bodies akin to ESSA and advancing clinical exercise physiology courses, highlighting their potential in global post-pandemic recovery efforts.

Impact of Physical Activity on Physical and Cognition Function among Community-Living Older Adults

Chapter

Full-text available

Jan 2024

Milan Chang Gudjonsson

The aging population presents unique challenges to healthcare systems worldwide, particularly in terms of maintaining physical function and cognitive abilities in old age. Physical activity (PA) is emerging as a potent intervention to enhance the well-being and functional independence of older individuals. The current review chapter will focus on the effect of PA on physical and cognitive function to provide comprehensive understanding of the interplay among community-dwelling older adults. The review (1) overviews the positive impact of PA on physical functions, including muscle strength, endurance, balance, and cardiovascular health, elucidating how these benefits contribute to improved mobility and reduced risk of falls among older adults, and (2) explores also how regular PA is associated with the cognitive benefits, including its preventive or delaying effect of cognitive decline, enhancements in memory, attention, executive function, and overall cognitive vitality. It emphasizes the critical role of PA in enhancing the overall capacity on managing daily living of older adults and offers insights into effective strategies for promoting active and healthy aging. These knowledge and insights can also guide healthcare practitioners, policymakers, and researchers in developing and implementing effective strategies to promote PA and support healthy aging in older populations.

Incidence of Dementia and Alzheimer’s Disease, Genetic Susceptibility, and Grip Strength Among Older Adults

Article

Full-text available

Oct 2023

Background Grip strength has prognostic value for aging-related health outcomes. Whether the associations of grip strength with risk of dementia and Alzheimer’s Disease (AD) vary by genetic risk of AD and related dementias (ADD) is unknown. Methods This study included 148,659 older adults of white British ancestry (aged ≥60 years) participating in UK Biobank with no dementia, self-reported poor health status at baseline. Polygenic risk scores (PRS) for ADD were calculated based on 64 genetic variants. Grip strength was measured by hand dynamometers. Results The hazard ratios (HR) of dementia (n=4,963) and AD (n=2,373) for high genetic risk of ADD were 2.36 (95% confidence interval [CI]: 2.15-2.59) and 3.00 (95% CI: 2.61-3.44), respectively, compared with low genetic risk. Compared with the bottom tertile of grip strength, the top tertile of grip strength had a hazard ratio (HR) of 0.69 (95% confidence interval [CI]: 0.64-0.74) for incident dementia, and 0.74 (95% CI: 0.66-0.82) for incident AD, after adjustment for confounders and PRS for ADD. Risk of dementia and AD was lower with the top grip strength tertile within each level of genetic susceptibility to ADD. There was no evidence of multiplicative interaction between grip strength and genetic susceptibility to ADD for both dementia (p-value: 0.241) and AD (p-value: 0.314). Conclusion Older adults with higher PRS for ADD are at higher risk of developing dementia and AD. Risk of dementia and AD was lower in individuals with higher grip strength, regardless of their level of genetic susceptibility to ADD.

The effects of a single bout of high-intense strength exercise on cognitive function and postural dual-task control in older adults

Article

Full-text available

Sep 2023

Review articles (Meta-Analyses) effects of walking on cognitive function in individuals with mild cognitive impairment: a systematic review and meta-analysis

Article

Full-text available

Aug 2023
BMC Geriatr

Background Mild cognitive impairment (MCI) is the stage between the expected cognitive decline of normal aging and the more serious decline of dementia. Previous studies have shown that regular exercise can improve cognition and physical performance in older adults. Walking is a low-technology and low-cost exercise that has been proven to improve cognition and mobility in healthy elderly individuals. However, no systematic review or meta-analysis has explored whether walking can improve cognitive function in older adults with MCI. This study aimed to explore the effects of walking interventions on cognitive functions in individuals with MCI. Methods In accordance with the PRISMA guidelines, MEDLINE, PubMed, SPORTDiscus, Cochrane Central Register of Controlled Trials, CINAHL, Web of Science, Airiti Library, and the National Digital Library of Theses and Dissertations in Taiwan were searched from inception to July 2023. Independent reviewers selected randomized clinical trials (RCT) that compared the effects of walking with no intervention or other exercises in individuals with MCI. The primary outcomes were cognitive functions, and the secondary outcome was walking endurance. Three reviewers independently conducted data extraction. The risk of bias was assessed using the Revised Cochrane Risk of Bias assessment tool. Results Fourteen RCTs were included in this review. The quality of evidence in these studies was rated as good to excellent. The results of the meta-analysis showed that the individuals with MCI had no significant improvement in cognitive function but had significant improvement in the 6-min walk test (Mean Difference=23.70, p=0.008) after walking interventions compared to no intervention or other exercises. Conclusion Walking intervention has no significant improvement on cognitive functions in older adults with MCI. However, walking induces beneficial effects on aerobic capacity. Trial registration This systematic review has the registration number CRD42021283753 on PROSPERO.

Preventing Alzheimer's Sherzai 2019

Article

Full-text available

Jul 2023

Dementia is the fastest growing epidemic in the developed nations, and if not curtailed, it will single handedly collapse our health care system. The prevalence of dementia is 1 in 10 individuals older than 65 years and increases to 50% of all individuals older than 85 years. The prevalence of Alzheimer's dementia (AD), the most common form of dementia, has been increasing rapidly and is projected to reach 16 million individuals by the year 2050.

Comparison of various exercise interventions on cognitive function in Alzheimer's patients: A network meta-analysis

Article

Jun 2023
ARCH GERONTOL GERIAT

Objective: Exercise helps enhance cognitive function in Alzheimer's patients, although the most effective forms of exercise remain unknown. Methods: This network meta-analysis was registered in INPLASY (INPLASY202330066). According to predetermined criteria, this investigation comprised randomized controlled studies involving exercise therapies in people with Alzheimer's disease. The exercise intervention was ranked using surface under the cumulative ranking curve (SUCRA) and mean ranking, with the critical goal outcomes being overall cognition, executive function, and memory function. Results: Resistance exercise is the most likely strategy to be beneficial for slowing down overall cognitive function loss in Alzheimer's patients (72.4%). Additionally, multi-component exercise was the most effective way to improve executive function (30.4%). The only type of exercise that significantly affects memory function is resistance exercise. Memory is the cognitive function that is least responsive to exercise. Conclusion: Resistance exercise may be an efficient intervention for overall cognitive function decline in patients with Alzheimer's and conjointly for their memory function. Multi-component exercise is more effective in improving executive function in patients with Alzheimer's disease.

Gait and/or balance disturbances associated with Alzheimer's dementia among older adults with amnestic mild cognitive impairment: A longitudinal observational study

Article

Full-text available

Jun 2023
J ADV NURS

Aims To explore whether gait and/or balance disturbances are associated with the onset of Alzheimer's dementia (AD) among older adults with amnestic mild cognitive impairment (MCI). Design This study employed a longitudinal retrospective cohort design. Methods We obtained data from the National Alzheimer's Coordinating Center's Uniform Data Set collected from 35 National Institute on Aging Alzheimer's Disease Research Centers between September 2005 and December 2021. The mean age of participants (n = 2692) was 74.5 years with women making up 47.2% of the sample. Risk of incident AD according to baseline gait and/or balance disturbances as measured using the Postural Instability and Gait Disturbance Score, a subscale of the Unified Parkinson's Disease Rating Scale Motor Score, was examined by the Cox proportional hazards regression models adjusting for baseline demographics, medical conditions and study sites. The mean follow‐up duration was 4.0 years. Results Among all the participants, the presence or the severity of gait and/or balance disturbances was associated with an increased risk of AD. The presence or the severity of gait and/or balance disturbances was associated with a higher risk of Alzheimer's dementia among the subgroups of female and male participants. Conclusion Gait and/or balance disturbances may increase the risk of developing AD, regardless of sex. Impact Gait and/or balance disturbances among community‐dwelling older adults with amnestic MCI may need to be frequently assessed by nurses to identify potential risk factors for cognitive decline. No patient or public contribution Given the secondary analysis, patients, service users, caregivers or members of the public were not directly involved in this study.

Active Gains in brain Using Exercise During Aging (AGUEDA): protocol for a randomized controlled trial

Article

Full-text available

May 2023
FRONT HUM NEUROSCI

Alzheimer’s disease is currently the leading cause of dementia and one of the most expensive, lethal and severe diseases worldwide. Age-related decline in executive function is widespread and plays a key role in subsequent dementia risk. Physical exercise has been proposed as one of the leading non-pharmaceutical approaches to improve executive function and ameliorate cognitive decline. This single-site, two-arm, single-blinded, randomized controlled trial (RCT) will include 90 cognitively normal older adults, aged 65–80 years old. Participants will be randomized to a 24-week resistance exercise program (3 sessions/week, 60 min/session, n = 45), or a wait-list control group (n = 45) which will be asked to maintain their usual lifestyle. All study outcomes will be assessed at baseline and at 24-weeks after the exercise program, with a subset of selected outcomes assessed at 12-weeks. The primary outcome will be indicated by the change in an executive function composite score assessed with a comprehensive neuropsychological battery and the National Institutes of Health Toolbox Cognition Battery. Secondary outcomes will include changes in brain structure and function and amyloid deposition, other cognitive outcomes, and changes in molecular biomarkers assessed in blood, saliva, and fecal samples, physical function, muscular strength, body composition, mental health, and psychosocial parameters. We expect that the resistance exercise program will have positive effects on executive function and related brain structure and function, and will help to understand the molecular, structural, functional, and psychosocial mechanisms involved.

Study on the Effectiveness of Multimodal Interventions (TEKEN program) to Improve Cognitive Function of the Elderly

Article

Full-text available

Dec 2021

Multimodal and single modal showed modest effects in slowing the progression of dementia. Our aim was to assess the impact of a multimodal intervention on the cognitive function of the elderly compared to a single modality. Methods: Multistage random sampling in Surakarta, Indonesia. The multimodal intervention consisted of a combination of cognitive training and gymnastics packaged with the term TEKEN program (Telaten, Eling, Kekancan, Etung, seNeng) and a single modal covering cognitive training, gymnastics and health education. Implementation 2 times a week for 24 meetings. Measurement of cognitive function using The Mini Mental State Exam (MMSE) and The Montreal of Cognitive Assessment (MoCA) Indonesian version was carried out at the beginning and end (3 months). Analysis using effect size / ES (d), logistic regression, correlation Kendall Tau Test. Results: 188 included in the final analysis, divided into 61 groups with the TEKEN program, cognitive training: 40, gymnastics: 49 and health education: 38. The TEKEN program has a fairly large ES (d) (0.46) smaller than the cognitive training program. and smaller than the gymnastics program on the MMSE measurement, while in MoCA-Ina, the TEKEN program has a small ES (d) (0.19) but is larger than the cognitive program and more than the gymnastics program. The ES value of MoCA-Ina can be the initial standard value in the next study. Conclusion: Multimodal and single modal can improve cognitive function in the elderly but multimodal has no more significant effect overall than single modality (cognitive training, gymnastics and health education).

Strength gains after 12 weeks of resistance training correlate with neurochemical markers of brain health in older adults: a randomized control 1H-MRS study

Article

Full-text available

Jan 2023

Physical exercise is considered a potent countermeasure against various age-associated physiological deterioration processes. We therefore assessed the effect of 12 weeks of resistance training on brain metabolism in older adults (age range: 60–80 years). Participants either underwent two times weekly resistance training program which consisted of four lower body exercises performed for 3 sets of 6–10 repetitions at 70–85% of 1 repetition maximum (n = 20) or served as the passive control group (n = 21). The study used proton magnetic resonance spectroscopy to quantify the ratio of total N-acetyl aspartate, total choline, glutamate-glutamine complex, and myo-inositol relative to total creatine (tNAA/tCr, tCho/tCr, Glx/tCr, and mIns/tCr respectively) in the hippocampus (HPC), sensorimotor (SM1), and prefrontal (dlPFC) cortices. The peak torque (PT at 60°/s) of knee extension and flexion was assessed using an isokinetic dynamometer. We used repeated measures time × group ANOVA to assess time and group differences and correlation coefficient analyses to examine the pre-to-post change (∆) associations between PT and neurometabolite variables. The control group showed significant declines in tNAA/tCr and Glx/tCr of SM1, and tNAA/tCr of dlPFC after 12 weeks, which were not seen in the experimental group. A significant positive correlation was found between ∆PT knee extension and ∆SM1 Glx/tCr, ∆dlPFC Glx/tCr and between ∆PT knee flexion and ∆dlPFC mIns/tCr in the experimental group. Overall, findings suggest that resistance training seems to elicit alterations in various neurometabolites that correspond to exercise-induced “preservation” of brain health, while simultaneously having its beneficial effect on augmenting muscle functional characteristics in older adults. Supplementary Information The online version contains supplementary material available at 10.1007/s11357-023-00732-6.

Study protocol for the BRAIN Training Trial: a randomised controlled trial of Balance, Resistance, And INterval training on cognitive function in older adults with mild cognitive impairment

Article

Full-text available

Dec 2022

Introduction Epidemiological evidence suggests that both poor cardiovascular fitness and low muscle mass or strength markedly increase the rate of cognitive decline and incident dementia in older adults. Results from exercise trials for the improvement of cognition in older adults with mild cognitive impairment (MCI) have reported mixed results. This is possibly due to insufficient exercise intensities. The aim of the Balance, Resistance, And INterval (BRAIN) Training Trial is to determine the effects of two forms of exercise, high-intensity aerobic interval training (HIIT) and high-intensity power training (POWER) each compared with a sham exercise control group on cognition in older adults with MCI. Methods and analysis One hundred and sixty community-dwelling older (≥ 60 years) people with MCI have been randomised into the trial. Interventions are delivered supervised 2–3 days per week for 12 months. The primary outcome measured at baseline, 6 and 12 months is performance on a cognitive composite score measuring the executive domain calculated from a combination of computerised (NeuroTrax) and paper-and-pencil tests. Analyses will be performed via repeated measures linear mixed models and generalised linear mixed models of baseline, 6-month and 12-month time points, adjusted for baseline values and covariates selected a priori. Mixed models will be constructed to determine the interaction of GROUP × TIME. Ethics and dissemination Ethical approval was obtained from the University of Sydney (HREC Ref.2017/368), University of Queensland (HREC Ref. 2017/HE000853), University of British Columbia (H16-03309), and Vancouver Coastal Health Research Institute (V16-03309) Human Research Ethics. Dissemination will be via publications, conference presentations, newsletter articles, social media, talks to clinicians and consumers and meetings with health departments/managers. It is expected that communication of results will allow for the development of more effective evidence-based exercise prescription guidelines in this population while investigating the benefits of HIIT and POWER on subclinical markers of disease. Trial registration number ACTRN12617001440314 Australian New Zealand Clinical Trials Registry.

Influence of a 12-Month Structured Exercise Program on the Micronutrient-Cognitive Fitness-Physical Association Profiles in Mild Cognitive Impairment

Article

Full-text available

Nov 2022

Background Preventive lifestyle strategies have shown promise to slow down or prevent age-related cognitive decline. However, evidence on the reciprocal longitudinal relationships between nutrition biomarkers and cognitive and physical performance is lacking. Studying nutritional, cognitive, and physical profiles over time may help to overcome this knowledge gap. Objective To investigate the relationship of plasma levels of the robust nutritional- and antioxidant defense-related biomarkers carotenoids and tocopherols with both indicators of cognitive and physical performance in persons with mild cognitive impairment (MCI) participating in a structured exercise program. Methods Data from 40 participants with MCI of the NeuroExercise study were analyzed. Participants had undergone a blood withdrawal for the analysis of plasma concentrations of six carotenoids, two tocopherols and retinol prior to and after one-year of structured exercise. All participants had undergone a broad spectrum of cognitive and physical performance tests. Results Significant associations between lipophilic micronutrients and cognitive/physical measures were observed that were previously found to play a role in cognitive and physical frailty. In particular, lutein, zeaxanthin, and lycopene are confirmed as robust, reliable, and stable indicators of nutritional defense. Importantly, these micronutrients were associated with cognitive measures prior to the physical training program and to a more prominent extent with indicators of motoric function after the physical exercise program. Conclusion Specific profiles of lipophilic micronutrients are associated to cognitive performance measures and, especially after a structured exercise program, to indicators of physical performance.

Promoting independence in Lewy body dementia through exercise: the PRIDE study

Article

Full-text available

Aug 2022
BMC Geriatr

Abstract Background Lewy body dementia (LBD) is an aggressive type of dementia of rapid, fluctuating disease trajectory, higher incidence of adverse events, and poorer functional independence than observed in Alzheimer’s disease dementia. Non-pharmacological treatments such as progressive, high-intensity exercise are effective in other neurological cohorts but have been scarcely evaluated in LBD. Methods The Promoting Independence in Lewy Body Dementia through Exercise (PRIDE) trial was a non-randomised, non-blinded, crossover pilot trial involving older adults with LBD consisting of a baseline assessment, an 8-week wait-list, and an 8-week exercise intervention. The aims of this study were to evaluate the determinants of the primary outcome functional independence, as measured by the Movement Disorder Society Unified Parkinson’s Disease Rating Scale, and the feasibility and preliminary efficacy of an exercise intervention on this outcome. Additionally, important clinical characteristics were evaluated to explore associations and treatment targets. The exercise intervention was supervised, clinic-based, high-intensity progressive resistance training (PRT), challenging balance, and functional exercises, 3 days/week. Results Nine participants completed the baseline cross-sectional study, of which five had a diagnosis of Parkinson’s disease dementia (PDD), and four dementia with Lewy Bodies (DLB). Six completed the exercise intervention (three PDD, three DLB). The cohort was diverse, ranging from mild to severe dementia and living in various residential settings. Greater functional independence at baseline was significantly associated with better physical function, balance, cognition, quality of life, muscle mass ratio, walking endurance, faster walking speed and cadence, and lower dementia severity (p

Exploring the Associations between Functional Capacity, Cognitive Function and Well-Being in Older Adults

Article

Full-text available

Jul 2022

Background: The present study aimed to explore the associations between functional capacity and global cognition, executive function and well-being in older adults. Methods: Ninety seven older adults (age 80.6 � 8.2 years) were examined for global cognitive function (Mini-Mental State Examination), executive function (symbol cancellation test), functional capacity (sit-to-stand tests, 6 min walk test, timed up-and-go test and handgrip strength test) and well-being (quality of life, fatigue levels, sleep quality and daily sleepiness). Adjusted partial correlations were computed to examine the associations between variables. Mediation analyses were conducted to evaluate whether functional capacity would mediate the relationships between age and cognitive or executive function. Results: Greater levels of functional capacity were associated with better performance in cognitive and executive function tests (p < 0.05). Mediation analyses revealed that functional capacity partially mediated the effects of age on global cognition and executive function (indirect effect: β = -0.11, 95% CI = -0.20 to -0.03; β = 0.34, 95% CI = 0.13 to 0.57, respectively). Increased levels of functional capacity were also associated with higher quality of life (p < 0.05, r = 0.32 to 0.41), lower fatigue levels (p < 0.05, r = 0.23 to 0.37), and better sleep quality (p < 0.05, r = 0.23 to 0.24). Conclusions: Functional capacity can mediate the effects of age on global cognition and executive function in older adults and greater levels of functional capacity are associated with improved quality of life, better sleep quality, and lower fatigue levels.

Is High-intensity Interval Training a Feasible Therapy Option in Geriatric Rehabilitation? A Randomized Controlled Pilot Study

Article

Jul 2022

Background With an increasing number of inpatients in geriatric rehabilitation, there is continuing interest in efficient training measures regarding physical performance.Objectives To examine the feasibility and outcomes of high-intensity interval training (HIIT) in geriatric patients. Methods Single-centre randomized controlled study of HIIT vs. moderate continuous training (MCT) for patients ≥65 years old referred to inpatient rehabilitation. Cardiopulmonary exercise testing (CPET) was performed before the first and last training in order to measure participant’s cardiorespiratory fitness. At the same time-points patients completed a series of questionnaires regarding subjective improvements and acceptance of the training methods. Results Regarding feasibility, HIIT showed a completion rate of 82.4% and an adherence rate of completed sessions of 83.3%. HIIT significantly improved cardiorespiratory fitness (+13% for VO2peak, p=0.01), respiratory quotient (+9%, p=0.01) and power output (+12% for Watt peak, p=0.01) compared with MCT. Significant improvements were also seen over time for physical and mental scores of PROMIS-10 and quality of life. Conclusion A HIIT intervention has proven feasible for elderly patients in a geriatric rehabilitative setting. Further research should specify the HIIT intervention in order to offer this training to more patients. Long-term observations are also needed.

Effects of a multicomponent resistance-based exercise program with protein, vitamin D and calcium supplementation on cognition in men with prostate cancer treated with ADT: secondary analysis of a 12-month randomised controlled trial

Article

Full-text available

Jun 2022

Objectives The aim of this preplanned secondary analysis of a 12-month randomised controlled trial was to investigate the effects of a multicomponent exercise programme combined with daily whey protein, calcium and vitamin D supplementation on cognition in men with prostate cancer treated with androgen deprivation therapy (ADT). Design 12-month, two-arm, randomised controlled trial. Setting University clinical exercise centre. Participants 70 ADT-treated men were randomised to exercise-training plus supplementation (Ex+ Suppl, n=34) or usual care (control, n=36). Intervention Men allocated to Ex + Suppl undertook thrice weekly resistance training with weight-bearing exercise training plus daily whey protein (25 g), calcium (1200 mg) and vitamin D (2000 IU) supplementation. Primary and secondary outcome measures Cognition was assessed at baseline, 6 and 12 months via a computerised battery (CogState), Trail-making test, Rey auditory-verbal learning test and Digit span. Data were analysed with linear mixed models and an intention-to-treat and prespecified per-protocol approach (exercise-training: ≥66%, nutritional supplement: ≥80%). Results Sixty (86%) men completed the trial (Ex + Suppl, n=31; control, n=29). Five (7.1%) men were classified as having mild cognitive impairment at baseline. Median (IQR) adherence to the exercise and supplement was 56% (37%–82%) and 91% (66%–97%), respectively. Ex + Suppl had no effect on cognition at any time. Conclusions A 12-month multicomponent exercise training and supplementation intervention had no significant effect on cognition in men treated with ADT for prostate cancer compared with usual care. Exercise training adherence below recommended guidelines does not support cognitive health in men treated with ADT for prostate cancer. Trial registration number Australian and New Zealand Clinical Trial Registry (ACTRN12614000317695, registered 25/03/2014) and acknowledged under the Therapeutic Goods Administration Clinical Trial Notification Scheme (CT-2015-CTN-03372-1 v1).

The Effects of Resistance Training on Physical Fitness and Neuromotor-Cognitive Functions in Adults With Down Syndrome

Article

Full-text available

Jun 2022

Adults with Down syndrome are an underserved population at high risk for a host of different pathologies from aging and lack of activity. Purpose To examine the effects of a 10-week resistance training program on measures of motor behavior, cognitive function, mood, and physical fitness. Methods Participants ( n = 11) were men and women clinically diagnosed with Down syndrome (age: 25.8 ± 6.4 years; height: 151.5 ± 8.3 cm; weight: 67.5 ± 13.0 kg; IQ: 58.3 ± 19.7 units). After familiarization of testing procedures, subjects performed The Arizona Cognitive Test Battery for Down Syndrome, TGMD-2, lower and upper body strength assessments, and body composition via DXA testing, while parental guardians completed cognitive and mood survey assessments (Cognitive Scale for Down Syndrome, Behavioral Rating Inventory of Executive Function, NiSonger Child Behavior Rating Form, Scales of Independent Behavior-Revised, Child Eating Behavior Questionnaire, Social Communication Questionnaire, and Mood and Feelings Questionnaire) at pre and post 10 weeks of periodized resistance training. Results Significant ( P ≤ 0.05) improvements in locomotor skills and object control skills were observed post-training. Both locomotor skills (e.g., sprint, gallop, leaping, broad jump) and object control skills (e.g., baseball catch, underhand roll, basketball dribble) were all significantly improved. Facets of cognitive performance significantly improved, specifically executive function and visuospatial working memory capacity, and frontal lobe activity. Mood disturbances significantly decrease. All aspects of physical strength and endurance were improved, i.e., leg press, bench press, sit-ups, push-ups, and chair sit-to-stand post-training. Lean tissue mass was significantly increased post-training. Conclusion This study dramatically demonstrates that life enhancements for individuals with Down syndrome are achievable with a properly designed resistance training program.

Strength-Cognitive Training: A Systemic Review in Adults and Older Adults, and Guidelines to Promote “Strength Exergaming” Innovations

Article

Full-text available

May 2022

Background Despite functional and cognitive benefits, few adults and older adults do strength training twice per week with sufficient intensity. Exercise-based active video games (exergaming) may amplify the cognitive benefits of exercise and increase adherence and motivation toward training. However, the benefits of a well-defined and monitored dose of strength training, executed simultaneously or sequentially with a cognitive element, has received little attention. In this study we have two aims: First, to systematically gather the available evidence; second, to suggest possible ways to promote strength exergaming innovations. Methods We systematically reviewed randomized controlled trials using simultaneous or sequent combined strength and cognitive training or strength exergaming to improve cognitive or functional outcomes in adults and older adults. Results After screening 1,785 studies (Google Scholar, ACM Digital Library, IEEE Xplore Library, PsycARTICLES, Scopus, Cochrane Library and PubMed) we found three eligible studies. Of the two studies using sequent strength and cognitive training, one showed improved functionality, but the other showed negative effects on cognition. The third study using simultaneous intervention, reported a positive influence on both cognition and function, when compared with either strength training alone or a control group. Moderate level of evidence was showed on GRADE analysis. Conclusion The existing little evidence suggests that strength and cognitive training improves cognition and function in adults and older adults. The following suggestions may help to promote further innovation: (1) ensure minimal dosage of strength training (30–60 min, 2 × /week), (2) use machine-based strength training devices to control volume and intensity (to prevent cognitive components from interfering with strength training), (3) include power training by using cognitive tasks requiring rapid reactions, and (4) add cognitive memory tasks (to extend the cognitive benefits of strength training per se), and (5) include motivational exergame elements to increase adherence.

The Effects of High-Intensity Functional Training on Cognition in Older Adults with Cognitive Impairment: A Systematic Review

Article

Full-text available

Apr 2022

(1) Background: High-Intensity Functional Training (HIFT) is a new exercise modality that emphasizes multi-joint functional movements adaptable to any fitness level and promotes greater muscle recruitment. Previous studies have evaluated the positive effects of HIFT on mental and cognitive health but have not evaluated it in older people. This study aims to conduct a systematic review of randomized controlled trials assessing the effects of HIFT on general cognition in older adults with cognitive impairment. (2) Methods: Following the PRISMA 2020 guideline, articles that did a high-intensity functional physical exercise intervention on cognitive performance in older adults with mild to moderate cognitive impairment (MMSE > 10) or dementia, aged 55 years or older, published between 2011 and 2021 in five different electronic databases: PubMed, Web of Science, Scopus, CINAHL, and Cochrane plus were included. (3) Results: 7 articles were included, all having general cognition as their primary outcome. All assessed general cognition using the Mini-Mental State Examination, the ADAS-Cog, or both. All studies had at least one HIFT experimental group with a frequency of 2 sessions per week and a variable duration between protocols of 12, 13, 16, and 26 weeks. Two articles showed that a progressive HIFT program improves general cognition, four articles showed no significant changes within or between groups and one article concluded that a HIFT intervention does not slow cognitive decline. (4) Conclusions: Evidence exists of the benefits of HIFT on general cognition in older adults with cognitive impairment, assessed using the MMSE, the ADAS-cog, or both. Two articles that showed improvement in cognitive function used progressive HIFT with 80% RM at 6, 12, and 1 weeks; however, in the other articles, due to the heterogeneity of intervention protocols, measurement time points, and control group activities, mixed results were evidenced

Effects of resistance training on cognitive and physical function in older adults with mild cognitive impairment: A Systematic Review

Article

Dec 2024

Jung-Hyun Kim

Risk of dementia in patients with age-related medical conditions: a retrospective cohort study

Article

Nov 2024
PSYCHOGERIATRICS

Hee-Cheol Kim

Objective This retrospective cohort study aimed to investigate the impact of age‐related medical conditions on the incidence of dementia, considering factors such as hypertension, diabetes mellitus, cerebrovascular disease, cardiovascular disease, chronic kidney disease, osteoarthritis, osteoporosis, chronic obstructive pulmonary disease, and hearing difficulties. Methods Data from 513 640 patients at Keimyung University Dongsan Hospital were analyzed using the Observational Medical Outcomes Partnership Common Data Model. Patients with and without age‐related medical conditions were assigned to experimental and control groups, respectively, with propensity score matching. Cox proportional hazards models assessed the association between each condition and dementia incidence. Results Hypertension, diabetes mellitus, cerebrovascular disease, cardiovascular disease, chronic kidney disease, osteoarthritis, osteoporosis, and hearing difficulties were associated with increased dementia risk. Chronic obstructive pulmonary disease showed no significant association with increased risk of dementia. Incidence rates ranged from 4.52 to 8.05 per 1000 person‐years in the control group and 7.46 to 14.99 per 1000 person‐years in the experimental group. Hazard ratios ranged from 1.38 to 2.36. Conclusions The study highlights the importance of managing age‐related medical conditions to mitigate dementia risk. Understanding these risk factors can inform preventive strategies and improve cognitive health outcomes. Problems with deidentification data analysis and the need for further multicentred studies are among the limitations of this study.

A review of the application of exercise intervention on improving cognition in patients with Alzheimer's disease: mechanisms and clinical studies

Article

Jul 2024
REV NEUROSCI

Alzheimer’s disease (AD) is the most common form of dementia, leading to sustained cognitive decline. An increasing number of studies suggest that exercise is an effective strategy to promote the improvement of cognition in AD. Mechanisms of the benefits of exercise intervention on cognitive function may include modulation of vascular factors by affecting cardiovascular risk factors, regulating cardiorespiratory health, and enhancing cerebral blood flow. Exercise also promotes neurogenesis by stimulating neurotrophic factors, affecting neuroplasticity in the brain. Additionally, regular exercise improves the neuropathological characteristics of AD by improving mitochondrial function, and the brain redox status. More and more attention has been paid to the effect of Aβ and tau pathology as well as sleep disorders on cognitive function in persons diagnosed with AD. Besides, there are various forms of exercise intervention in cognitive improvement in patients with AD, including aerobic exercise, resistance exercise, and multi-component exercise. Consequently, the purpose of this review is to summarize the findings of the mechanisms of exercise intervention on cognitive function in patients with AD, and also discuss the application of different exercise interventions in cognitive impairment in AD to provide a theoretical basis and reference for the selection of exercise intervention in cognitive rehabilitation in AD.

The Effects of Different Types of Exercises on Cognition in Older Persons with Mild Cognitive Impairment: A Systematic Review and Meta-Analysis

Article

Jul 2024
ARCH GERONTOL GERIAT

This systematic review with meta-analysis aims to analyze the effects of different types of exercise on cognition, neuroprotective and neuroinflammatory blood markers in older adults with mild cognitive impairment (MCI). Relevant studies were identified using PubMED, SPORTDiscuss, Web of Science, Scopus, and PsycInfo databases. Methodological quality assessment of the studies was done with modified Downs and Black checklist. Data obtained from the included studies was analyzed using Comprehensive Meta-Analysis 4.0 software and results were reported using the random effects method. A total of twenty-three studies were identified. The findings were summarized as change in cognitive function after the exercise interventions in general and after each type of exercise. On average, the exercise intervention revealed an effect size (ES): 1.165; 0.741 to 1.589 (95% Confidence Interval (CI); p < 0.001); aerobic exercise ES: 1.442; 0.624 to 2.260 (95 %CI); p = 0.001; Multimodal ES: 0,856; 0.366 to 1.346 (95 % CI); p = 0.001 and resistance exercise ES: 1.229; 0.339 to 2.120 (95 % CI); p = 0.007. In addition, we observed significant small ES: -0.475; -0.817 to -0.134 (95 %CI); p = 0.006, I2= 0 %; τ2 = 0 of exercise effects on Tumor Necrosis Factor-α (TNF-α) and non-significant large ES:0.952; -0.238 to 2.142 (95 %CI); p = 0.117 on Brain Derived Neurotrophic Factor (BDNF) in persons with MCI. The present study revealed the existence of a large positive effect of overall exercise intervention on cognitive function and a small effect on TNF-α in old people with MCI. Additionally, this study demonstrates that aerobic and resistance exercises had similar larger positive effects and were better than multimodal exercise on increasing cognition in older persons with MCI.

Exercise promotes healthy cardiovascular aging

Article

Dec 2023
Acta Physiol Sin

Cardiovascular disease (CVD) is an important factor threatening the health of the elderly. Aging leads to changes in the structure and function of the cardiovascular system, which increases the risk of CVD in the elderly. Cardiac aging is characterized by increased left ventricular wall thickness, increased degree of myocardial fibrosis, increased cardiac hardness, and decreased cardiac function, while vascular aging is characterized by enlarged lumen, thickened wall, and endothelial dysfunction. Promoting healthy cardiovascular aging means reducing the age-related cardiovascular dysfunction and the risks of CVD. Exercise is a crucial means for the treatment and rehabilitation of CVD. Exercise reduces the risk factors of CVD, remodels the cardiovascular structure, and increases the resistance of heart to detrimental stimulus, which promotes healthy cardiovascular aging. The improved mitochondrial function via exercise plays a key role in the health effects of exercise. In addition, exercise promotes the secretion of exerkines in various tissues and organs, which plays a role in reducing inflammation, improving metabolism, inhibiting apoptosis, etc., thus benefiting cardiovascular health. This review discusses the mechanism and potential application of exercise in promoting healthy cardiovascular aging. Exploring the specific mechanisms underlying exercise-induced cardiovascular health and formulating accurate exercise prescriptions for different populations is an important direction to promote healthy cardiovascular aging and prevent CVD.

THE EFFECTS OF RESISTANCE PHYSICAL EXERCISE ON MEMORY AND COGNITIVE FUNCTION OF APP/PS1 MOUSE MODEL OF ALZHEIMER’S DISEASE

Article

Oct 2023

Prevalence and impact of cognitive impairment assessed by Mini-Cog in hospitalized cardiac rehabilitation referrals

Article

Jul 2023

Effects of a physical exercise or motor activity protocol on cognitive function, lipid profile, and BDNF levels in older adults with mild cognitive impairment

Article

Full-text available

Apr 2023
MOL CELL BIOCHEM

This study analyzed the effects of a physical exercise program compared to the complexity of the motor task on the cognitive function, brain-derived neurotrophic factor (BDNF) levels, and lipid profile of older adults with mild cognitive impairment (MCI). Twenty-seven participants were randomized into three intervention groups: Physical Exercise (PE), Motor Task (MT), and Physical Exercise associated with Motor Task (PE + MT). Six months of intervention twice a week resulted in improvements in cognitive function, total cholesterol (TC), and LDL cholesterol (LDL-C) in the PE (p < 0.05). In the PE + MT, in addition to improved cognitive capacity, there was also a reduction in non-HDL cholesterol (NHDL-C) and LDL cholesterol (LDL-C) levels (p < 0.05), while in the MT, the values of TC, NHDL-C, and LDL-C decreased as a result of the intervention. BDNF levels were not affected by the interventions. In conclusion, PE alone or combined with MT is effective in promoting improvements in overall cognitive function and lipid profile in older adults with MCI; and BDNF seems not to be a sensitive marker for people with mild cognitive impairment.

The effects of resistance exercise on cognitive function, amyloidogenesis, and neuroinflammation in Alzheimer’s disease

Article

Full-text available

Mar 2023

With the increasing prevalence of Alzheimer’s disease (AD) and difficulties in finding effective treatments, it is essential to discover alternative therapies through new approaches. In this regard, non-pharmacological therapies, such as physical exercise, have been proposed and explored for the treatment of AD. Recent studies have suggested that resistance exercise (RE) is an effective strategy for promoting benefits in memory and cognitive function, producing neuroprotective and anti-inflammatory effects, and reducing amyloid load and plaques, thereby reducing the risk, and alleviating the neurodegeneration process of AD and other types of dementia in the elderly. In addition, RE is the exercise recommended by the World Health Organization for the elderly due to its benefits in improving muscle strength and balance, and increasing autonomy and functional capacity, favoring improvements in the quality of life of the elderly population, who is more likely to develop AD and other types of dementia. In this mini-review, we discuss the impact of RE on humans affected by MCI and AD, and animal models of AD, and summarize the main findings regarding the effects of RE program on memory and cognitive functions, neurotrophic factors, Aβ deposition and plaque formation, as well as on neuroinflammation. Overall, the present review provides clinical and preclinical evidence that RE plays a role in alleviating AD symptoms and may help to understand the therapeutic potential of RE, thereby continuing the advances in AD therapies.

Which Specific Exercise Models Are Most Effective on Global Cognition in Patients with Cognitive Impairment? A Network Meta-Analysis

Article

Full-text available

Feb 2023
Int J Environ Res Publ Health

(1) Introduction: Physical exercise interventions can impart significant cognitive benefits to older adults suffering from cognitive impairment (CI). However, the efficacy of these interventions can vary widely, depending on the type, intensity, duration and frequency of exercise. (2) Aim: To systematically review the efficacy of exercise therapy on global cognition in patients with CI using a network meta-analysis (NMA). (3) Methods: The PubMed, Embase, Sport Discus (EBSCO) and Cochrane Library databases were electronically searched to collect randomized controlled trials (RCTs) on exercise for patients with CI from inception to 7 August 2022. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias of the included studies. The NMA was performed using the consistency model. (4) Results: A total of 29 RCTs comprising 2458 CI patients were included. The effects of different types of exercise on patients with CI were ranked as follows: multicomponent exercise (SMD = 0.84, 95% CI 0.31 to 1.36, p = 0.002), short duration (≤45 min) (SMD = 0.83, 95% CI 0.18 to 1.19, p = 0.001), vigorous intensity (SMD = 0.77, 95% CI 0.18 to 1.36, p = 0.011) and high frequency (5–7 times/week) (SMD = 1.28, 95% CI 0.41 to 2.14, p = 0.004). (5) Conclusion: These results suggested that multicomponent, short-duration, high-intensity, and high-frequency exercise may be the most effective type of exercise in improving global cognition in CI patients. However, more RCTs based on direct comparison of the effects of different exercise interventions are needed. (6) NMA registration identifier: CRD42022354978.

In-Hospital, 24-Hour Exercise Spaces for Resident and Staff Wellness

Article

Oct 2022

Association of Adherence to high-intensity physical activity and the Mediterranean-dietary approaches to stop hypertension intervention for neurodegenerative delay diet with cognition: A cross-sectional study

Article

Apr 2022
INT J NURS STUD

Background Prevention is a priority in the absence of a cure for dementia. Physical activity and a neuroprotective diet such as the Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) diet are healthy lifestyle behaviors that may slow the onset of dementia. However, research on the relationship between the combination of physical activity and the MIND diet and cognition is rare. Objectives The purpose of this study was to investigate whether the combination of high-intensity physical activity and the MIND diet is associated with better cognition compared with either behavior alone or neither behavior. Design A population-based, cross-sectional study was conducted using data from the Health and Retirement Study. Methods Using information from a total of 3463 participants (age 68.0 ± 10.0 years), multivariate linear regression models and binary logistic regression models with interaction terms between high-intensity physical activity (PA) and the MIND diet (MIND) were used to assess associations of PA and MIND with global cognition and odds of cognitive decline. Group comparisons were conducted among four groups: PA −/MIND −, PA +/MIND −, PA −/MIND +, and PA +/MIND +. Results PA +/MIND − did not predict cognitive outcomes (versus PA −/MIND −). PA −/MIND + was associated with better global cognition (mean difference [d] = 0.81; 95% confidence interval [CI] = 0.50–1.11; p < 0.001) and lower odds of cognitive decline (odds ratio [OR] = 0.68; 95% CI = 0.54–0.86; p = 0.001) (versus PA −/MIND −). PA +/MIND + predicted better global cognition (d = 0.98; 95% CI = 0.59–1.36; p < 0.001) and lower odds of cognitive decline (OR = 0.69; 95% CI = 0.50–0.94; p = 0.004) (versus PA −/MIND −). PA +/MIND + was associated with better global cognition (d = 0.60; 95% CI = 0.08–1.12; p < 0.001), but did not predict lower odds of cognitive decline (versus PA +/MIND −). PA +/MIND + did not predict cognitive outcomes (versus PA −/MIND +). Conclusions Combining high-intensity physical activity and the MIND diet was associated with better cognitive health than high-intensity physical activity alone or non-adherence to both behaviors. To potentially exert additive effects, it will be important to encourage these two healthy habits. More research on the role of combined physical activity and dietary change is necessary to further inform policy and clinical guidance. What is already known •Because there is no cure for dementia, prevention is a major issue. •A healthy lifestyle is a non-pharmacological way to potentially prevent dementia. •Physical activity or the Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) diet may improve cognitive function. What this paper adds •The influence of the combination of high-intensity physical activity and the MIND diet on cognitive health was investigated among a nationally representative sample of community-dwelling individuals without dementia. •The combination of high-intensity physical activity and the MIND diet was associated with better global cognition and a lower risk of cognitive decline compared with neither behavior. •Adding the MIND diet to high-intensity physical activity was associated with higher global cognition when compared with high-intensity physical activity only, which may imply an additive effect.

State of Knowledge on Molecular Adaptations to Exercise in Humans: Historical Perspectives and Future Directions

Chapter

Full-text available

Mar 2022

For centuries, regular exercise has been acknowledged as a potent stimulus to promote, maintain, and restore healthy functioning of nearly every physiological system of the human body. With advancing understanding of the complexity of human physiology, continually evolving methodological possibilities, and an increasingly dire public health situation, the study of exercise as a preventative or therapeutic treatment has never been more interdisciplinary, or more impactful. During the early stages of the NIH Common Fund Molecular Transducers of Physical Activity Consortium (MoTrPAC) Initiative, the field is well-positioned to build substantially upon the existing understanding of the mechanisms underlying benefits associated with exercise. Thus, we present a comprehensive body of the knowledge detailing the current literature basis surrounding the molecular adaptations to exercise in humans to provide a view of the state of the field at this critical juncture, as well as a resource for scientists bringing external expertise to the field of exercise physiology. In reviewing current literature related to molecular and cellular processes underlying exercise-induced benefits and adaptations, we also draw attention to existing knowledge gaps warranting continued research effort. © 2021 American Physiological Society. Compr Physiol 12:3193-3279, 2022.

IGF-1 deficiency impairs neurovascular coupling in mice: Implications for cerebromicrovascular aging

Article

Full-text available

Jul 2015
AGING CELL

Aging is associated with marked deficiency in circulating IGF-1, which has been shown to contribute to age-related cognitive decline. Impairment of moment-to-moment adjustment of cerebral blood flow (CBF) via neurovascular coupling is thought to play a critical role in the genesis of age-related cognitive impairment. To establish the link between IGF-1 deficiency and cerebromicrovascular impairment, neurovascular coupling mechanisms were studied in a novel mouse model of IGF-1 deficiency (Igf1(f/f) -TBG-Cre-AAV8) and accelerated vascular aging. We found that IGF-1-deficient mice exhibit neurovascular uncoupling and show a deficit in hippocampal-dependent spatial memory test, mimicking the aging phenotype. IGF-1 deficiency significantly impaired cerebromicrovascular endothelial function decreasing NO mediation of neurovascular coupling. IGF-1 deficiency also impaired glutamate-mediated CBF responses, likely due to dysregulation of astrocytic expression of metabotropic glutamate receptors and impairing mediation of CBF responses by eicosanoid gliotransmitters. Collectively, we demonstrate that IGF-1 deficiency promotes cerebromicrovascular dysfunction and neurovascular uncoupling mimicking the aging phenotype, which are likely to contribute to cognitive impairment. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

BDNF mediates improvements in executive function following a 1-year exercise intervention

Article

Full-text available

Dec 2014
FRONT HUM NEUROSCI

Executive function declines with age, but engaging in aerobic exercise may attenuate decline. One mechanism by which aerobic exercise may preserve executive function is through the up-regulation of brain-derived neurotropic factor (BDNF), which also declines with age. The present study examined BDNF as a mediator of the effects of a 1-year walking intervention on executive function in 90 older adults (mean age = 66.82). Participants were randomized to a stretching and toning control group or a moderate intensity walking intervention group. BDNF serum levels and performance on a task-switching paradigm were collected at baseline and follow-up. We found that age moderated the effect of intervention group on changes in BDNF levels, with those in the highest age quartile showing the greatest increase in BDNF after 1-year of moderate intensity walking exercise (p = 0.036). The mediation analyses revealed that BDNF mediated the effect of the intervention on task-switch accuracy, but did so as a function of age, such that exercise-induced changes in BDNF mediated the effect of exercise on task-switch performance only for individuals over the age of 71. These results demonstrate that both age and BDNF serum levels are important factors to consider when investigating the mechanisms by which exercise interventions influence cognitive outcomes, particularly in elderly populations.

The Study of Mental and Resistance Training (SMART) Study—Resistance Training and/or Cognitive Training in Mild Cognitive Impairment: A Randomized, Double-Blind, Double-Sham Controlled Trial

Article

Full-text available

Oct 2014

Background Mild cognitive impairment (MCI) increases dementia risk with no pharmacologic treatment available. Methods The Study of Mental and Resistance Training was a randomized, double-blind, double-sham controlled trial of adults with MCI. Participants were randomized to 2 supervised interventions: active or sham physical training (high intensity progressive resistance training vs seated calisthenics) plus active or sham cognitive training (computerized, multidomain cognitive training vs watching videos/quizzes), 2–3 days/week for 6 months with 18-month follow-up. Primary outcomes were global cognitive function (Alzheimer's Disease Assessment Scale-cognitive subscale; ADAS-Cog) and functional independence (Bayer Activities of Daily Living). Secondary outcomes included executive function, memory, and speed/attention tests, and cognitive domain scores. Results One hundred adults with MCI [70.1 (6.7) years; 68% women] were enrolled and analyzed. Resistance training significantly improved the primary outcome ADAS-Cog; [relative effect size (95% confidence interval) −0.33 (−0.73, 0.06); P < .05] at 6 months and executive function (Wechsler Adult Intelligence Scale Matrices; P = .016) across 18 months. Normal ADAS-Cog scores occurred in 48% (24/49) after resistance training vs 27% (14/51) without resistance training [P < .03; odds ratio (95% confidence interval) 3.50 (1.18, 10.48)]. Cognitive training only attenuated decline in Memory Domain at 6 months (P < .02). Resistance training 18-month benefit was 74% higher (P = .02) for Executive Domain compared with combined training [z-score change = 0.42 (0.22, 0.63) resistance training vs 0.11 (−0.60, 0.28) combined] and 48% higher (P < .04) for Global Domain [z-score change = .0.45 (0.29, 0.61) resistance training vs 0.23 (0.10, 0.36) combined]. Conclusions Resistance training significantly improved global cognitive function, with maintenance of executive and global benefits over 18 months.

Epidemiologic studies of modifiable factors associated with cognition and dementia: Systematic review and meta-analysis

Article

Full-text available

Jun 2014
BMC PUBLIC HEALTH

Background Cognitive impairment, including dementia, is a major health concern with the increasing aging population. Preventive measures to delay cognitive decline are of utmost importance. Alzheimer’s disease (AD) is the most frequent cause of dementia, increasing in prevalence from <1% below the age of 60 years to >40% above 85 years of age. Methods We systematically reviewed selected modifiable factors such as education, smoking, alcohol, physical activity, caffeine, antioxidants, homocysteine (Hcy), n-3 fatty acids that were studied in relation to various cognitive health outcomes, including incident AD. We searched MEDLINE for published literature (January 1990 through October 2012), including cross-sectional and cohort studies (sample sizes > 300). Analyses compared study finding consistency across factors, study designs and study-level characteristics. Selecting studies of incident AD, our meta-analysis estimated pooled risk ratios (RR), population attributable risk percent (PAR%) and assessed publication bias. Results In total, 247 studies were retrieved for systematic review. Consistency analysis for each risk factor suggested positive findings ranging from ~38.9% for caffeine to ~89% for physical activity. Education also had a significantly higher propensity for “a positive finding” compared to caffeine, smoking and antioxidant-related studies. Meta-analysis of 31 studies with incident AD yielded pooled RR for low education (RR = 1.99; 95% CI: 1.30-3.04), high Hcy (RR = 1.93; 95% CI: 1.50-2.49), and current/ever smoking status (RR = 1.37; 95% CI: 1.23-1.52) while indicating protective effects of higher physical activity and n-3 fatty acids. Estimated PAR% were particularly high for physical activity (PAR% = 31.9; 95% CI: 22.7-41.2) and smoking (PAR%=31.09%; 95% CI: 17.9-44.3). Overall, no significant publication bias was found. Conclusions Higher Hcy levels, lower educational attainment, and decreased physical activity were particularly strong predictors of incident AD. Further studies are needed to support other potential modifiable protective factors, such as caffeine.

Insulin-like growth factor-1 and risk of Alzheimer dementia and brain atrophy

Article

Full-text available

Apr 2014
NEUROLOGY

To relate serum insulin-like growth factor-1 (IGF-1) to risk of Alzheimer disease (AD) dementia and to brain volumes in a dementia-free community sample spanning middle and older ages. Dementia-free Framingham participants from generation 1 (n = 789, age 79 ± 4 years, 64% women) and generation 2 (n = 2,793, age 61 ± 9 years, 55% women; total = 3,582, age 65 ± 11 years, 57% women) had serum IGF-1 measured in 1990-1994 and 1998-2001, respectively, and were followed prospectively for incident dementia and AD dementia. Brain MRI was obtained in stroke- and dementia-free survivors of both generations 1 (n = 186) and 2 (n = 1,867) during 1999-2005. Baseline IGF-1 was related to risk of incident dementia using Cox models and to total brain and hippocampal volumes using linear regression in multivariable models adjusted for age, sex, APOE ε4, plasma homocysteine, waist-hip ratio, and physical activity. Mean IGF-1 levels were 144 ± 60 μg/L in generation 1 and 114 ± 37 μg/L in generation 2. We observed 279 cases of incident dementia (230 AD dementia) over a mean follow-up of 7.4 ± 3.1 years. Persons with IGF-1 in the lowest quartile had a 51% greater risk of AD dementia (hazard ratio = 1.51, 95% confidence interval: 1.14-2.00; p = 0.004). Among persons without dementia, higher IGF-1 levels were associated with greater total brain volumes (β/SD increment in IGF-1 was 0.55 ± 0.24, p = 0.025; and 0.26 ± 0.06, p < 0.001, for generations 1 and 2, respectively). Lower serum levels of IGF-1 are associated with an increased risk of developing AD dementia and higher levels with greater brain volumes even among middle-aged community-dwelling participants free of stroke and dementia. Higher levels of IGF-1 may protect against subclinical and clinical neurodegeneration.

Enhancing cognitive functioning in the elderly: Multicomponent vs resistance training

Article

Full-text available

Jan 2013
Clin Interv Aging

PURPOSE: The primary purpose of this study was to compare the effects of two different exercise training programs on executive cognitive functions and functional mobility in older adults. A secondary purpose was to explore the potential mediators of training effects on executive function and functional mobility with particular reference to physical fitness gains. METHODS: A sample of 42 healthy community dwelling adults aged 65 to 75 years participated twice weekly for 3 months in either: (1) multicomponent training, prioritizing neuromuscular coordination, balance, agility, and cognitive executive control; or (2) progressive resistance training for strength conditioning. Participants were tested at baseline (T(1)), following a 4-week control period (T(2)), and finally at postintervention (T(3)) for executive function (inhibition and cognitive flexibility) and functional mobility (maximal walking speed with and without additional task requirements). Cardiorespiratory and muscular fitness were also assessed as potential mediators. RESULTS: Indices of inhibition, the functions involved in the deliberate withholding of prepotent or automatic responses, and measures of functional mobility improved after the intervention, independent of training type. Mediation analysis suggested that different mechanisms underlie the effects of multicomponent and progressive resistance training. While multicomponent training seemed to directly affect inhibitory capacity, resistance training seemed to affect it indirectly through gains in muscular strength. Physical fitness and executive function variables did not mediate functional mobility changes. CONCLUSION: These results confirm that physical training benefits executive function and suggest that different training types might lead to such benefits through different pathways. Both types of training also promoted functional mobility in older adulthood; however, neither inhibitory capacity, nor muscular strength gains seemed to explain functional mobility outcomes.

Resistance Training Promotes Cognitive and Functional Brain Plasticity in Seniors With Probable Mild Cognitive Impairment

Article

Full-text available

Apr 2012

Correspondence: Dr Liu-Ambrose, Department of Physical Therapy, University of British Columbia, 212-2177 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada (tlambrose@exchange.ubc.ca). Author Contributions: All authors had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Voss and Liu-Ambrose. Acquisition of data: Nagamatsu, Hsu, and Liu-Ambrose. Analysis and interpretation of data: Nagamatsu, Handy, Voss, and Liu-Ambrose. Drafting of the manuscript: Nagamatsu, Handy, and Liu-Ambrose. Critical revision of the manuscript for important intellectual content: Nagamatsu, Handy, Hsu, Voss, and Liu-Ambrose. Statistical analysis: Nagamatsu, Voss, and Liu-Ambrose. Obtained funding: Liu-Ambrose. Administrative, technical, and material support: Nagamatsu, Hsu, Voss, and Liu-Ambrose. Study supervision: Handy and Liu-Ambrose. Financial Disclosure: None reported. Funding/Support: The Pacific Alzheimer's Research Foundation provided funding for this study (Dr Liu-Ambrose). Previous Presentation: Data from this manuscript were presented as a podium presentation at the International Society for Neuroimaging in Psychiatry; September 9, 2011; Heidelberg, Germany. Additional Information: Ms Nagamatsu is a Michael Smith Foundation for Health Research Senior Graduate trainee and a Natural Sciences and Engineering Research Council of Canada Doctoral trainee. Dr Liu-Ambrose is a Michael Smith Foundation for Health Research Scholar, a Canadian Institutes of Health Research New Investigator, and a Heart and Stroke Foundation of Canada's Henry J. M. Barnett's Scholarship recipient. Additional Contributions: Alison Chan, BSc, Jennifer C. Davis, PhD, B. Lynn Beattie, MD, and Peter Graf, PhD, made significant contributions to this study. We thank the instructors for their commitment to the participants' health and safety. This article was corrected for errors on July 10, 2013.

The Metabolic Syndrome, Inflammation, and Risk of Cognitive Decline

Article

Full-text available

Nov 2004
J Am Med Assoc

Several studies have reported an association between the metabolic syndrome and cardiovascular disease. Despite an increasing awareness that cardiovascular risk factors increase risk of cognitive decline and dementia, there are few data on the metabolic syndrome and cognition. To determine if the metabolic syndrome is a risk factor for cognitive decline and if this association is modified by inflammation. A 5-year prospective observational study conducted from 1997 to 2002 at community clinics at 2 sites. A total of 2632 black and white elders (mean age, 74 years). Association of the metabolic syndrome (measured using National Cholesterol Education Program guidelines) and high inflammation (defined as above median serum level of interleukin 6 and C-reactive protein) with change in cognition (Modified Mini-Mental State Examination [3MS]) at 3 and 5 years. Cognitive impairment was defined as at least a 5-point decline. Compared with those without the metabolic syndrome (n = 1616), elders with the metabolic syndrome (n = 1016) were more likely to have cognitive impairment (26% vs 21%, multivariate adjusted relative risk [RR], 1.20; 95% confidence interval [CI], 1.02-1.41). There was a statistically significant interaction with inflammation and the metabolic syndrome (P = .03) on cognitive impairment. After stratifying for inflammation, those with the metabolic syndrome and high inflammation (n = 348) had an increased likelihood of cognitive impairment compared with those without the metabolic syndrome (multivariate adjusted RR, 1.66; 95% CI, 1.19-2.32). Those with the metabolic syndrome and low inflammation (n = 668) did not exhibit an increased likelihood of impairment (multivariate adjusted RR, 1.08; 95% CI, 0.89-1.30). Stratified multivariate random-effects models demonstrated that participants with the metabolic syndrome and high inflammation had greater 4-year decline on 3MS (P = .04) compared with those without the metabolic syndrome, whereas those with the metabolic syndrome and low inflammation did not (P = .44). These findings support the hypothesis that the metabolic syndrome contributes to cognitive impairment in elders, but primarily in those with high level of inflammation.

Study of Mental Activity and Regular Training (SMART) in at risk individuals: A randomised double blind, sham controlled, longitudinal trial

Article

Full-text available

Apr 2011
BMC Geriatr

The extent to which mental and physical exercise may slow cognitive decline in adults with early signs of cognitive impairment is unknown. This article provides the rationale and methodology of the first trial to investigate the isolated and combined effects of cognitive training (CT) and progressive resistance training (PRT) on general cognitive function and functional independence in older adults with early cognitive impairment: Study of Mental and Regular Training (SMART). Our secondary aim is to quantify the differential adaptations to these interventions in terms of brain morphology and function, cardiovascular and metabolic function, exercise capacity, psychological state and body composition, to identify the potential mechanisms of benefit and broader health status effects. SMART is a double-blind randomized, double sham-controlled trial. One hundred and thirty-two community-dwelling volunteers will be recruited. Primary inclusion criteria are: at risk for cognitive decline as defined by neuropsychology assessment, low physical activity levels, stable disease, and age over 55 years. The two active interventions are computerized CT and whole body, high intensity PRT. The two sham interventions are educational videos and seated calisthenics. Participants are randomized into 1 of 4 supervised training groups (2 d/wk×6 mo) in a fully factorial design. Primary outcomes measured at baseline, 6, and 18 months are the Alzheimer's Disease Assessment Scale (ADAS-Cog), neuropsychological test scores, and Bayer Informant Instrumental Activities of Daily Living (B-IADLs). Secondary outcomes are psychological well-being, quality of life, cardiovascular and musculoskeletal function, body composition, insulin resistance, systemic inflammation and anabolic/neurotrophic hormones, and brain morphology and function via Magnetic Resonance Imaging (MRI) and Spectroscopy (fMRS). SMART will provide a novel evaluation of the immediate and long term benefits of CT, PRT, and combined CT and PRT on global cognitive function and brain morphology, as well as potential underlying mechanisms of adaptation in older adults at risk of further cognitive decline. Australia and New Zealand Clinical Trials Register (ANZCTR): ANZCTRN12608000489392.

Exercise Training Increases Size of Hippocampus and Improves Memory

Article

Full-text available

Feb 2011
P NATL ACAD SCI USA

The hippocampus shrinks in late adulthood, leading to impaired memory and increased risk for dementia. Hippocampal and medial temporal lobe volumes are larger in higher-fit adults, and physical activity training increases hippocampal perfusion, but the extent to which aerobic exercise training can modify hippocampal volume in late adulthood remains unknown. Here we show, in a randomized controlled trial with 120 older adults, that aerobic exercise training increases the size of the anterior hippocampus, leading to improvements in spatial memory. Exercise training increased hippocampal volume by 2%, effectively reversing age-related loss in volume by 1 to 2 y. We also demonstrate that increased hippocampal volume is associated with greater serum levels of BDNF, a mediator of neurogenesis in the dentate gyrus. Hippocampal volume declined in the control group, but higher preintervention fitness partially attenuated the decline, suggesting that fitness protects against volume loss. Caudate nucleus and thalamus volumes were unaffected by the intervention. These theoretically important findings indicate that aerobic exercise training is effective at reversing hippocampal volume loss in late adulthood, which is accompanied by improved memory function.

Resistance Training and Executive FunctionsA 12-Month Randomized Controlled TrialResistance Training and Executive Functions

Article

Full-text available

Jan 2010

Cognitive decline among seniors is a pressing health care issue. Specific exercise training may combat cognitive decline. We compared the effect of once-weekly and twice-weekly resistance training with that of twice-weekly balance and tone exercise training on the performance of executive cognitive functions in senior women. In this single-blinded randomized trial, 155 community-dwelling women aged 65 to 75 years living in Vancouver were randomly allocated to once-weekly (n = 54) or twice-weekly (n = 52) resistance training or twice-weekly balance and tone training (control group) (n = 49). The primary outcome measure was performance on the Stroop test, an executive cognitive test of selective attention and conflict resolution. Secondary outcomes of executive cognitive functions included set shifting as measured by the Trail Making Tests (parts A and B) and working memory as assessed by verbal digit span forward and backward tests. Gait speed, muscular function, and whole-brain volume were also secondary outcome measures. Both resistance training groups significantly improved their performance on the Stroop test compared with those in the balance and tone group (P < or = .03). Task performance improved by 12.6% and 10.9% in the once-weekly and twice-weekly resistance training groups, respectively; it deteriorated by 0.5% in the balance and tone group. Enhanced selective attention and conflict resolution was significantly associated with increased gait speed. Both resistance training groups demonstrated reductions in whole-brain volume compared with the balance and tone group at the end of the study (P < or = .03). Twelve months of once-weekly or twice-weekly resistance training benefited the executive cognitive function of selective attention and conflict resolution among senior women. clinicaltrials.gov Identifier: NCT00426881.

Effects of Aerobic Exercise on Mild Cognitive Impairment: A Controlled Trial

Article

Full-text available

Jan 2010

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.

Association of Muscle Strength With the Risk of Alzheimer Disease and the Rate of Cognitive Decline in Community-Dwelling Older Persons

Article

Full-text available

Nov 2009

Loss of muscle strength is common and is associated with various adverse health outcomes in old age, but few studies have examined the association of muscle strength with the risk of Alzheimer disease (AD) or mild cognitive impairment (MCI). To test the hypothesis that muscle strength is associated with incident AD and MCI. Prospective observational cohort study. Retirement communities across the Chicago, Illinois, metropolitan area. More than 900 community-based older persons without dementia at the baseline evaluation and in whom strength was measured in 9 muscle groups in arms and legs, and in the axial muscles and summarized into a composite measure of muscle strength. Incident AD and MCI and the rate of change in global cognitive function. During a mean follow-up of 3.6 years, 138 persons developed AD. In a proportional hazards model adjusted for age, sex, and education status, each 1-U increase in muscle strength at baseline was associated with about a 43% decrease in the risk of AD (hazard ratio, 0.57; 95% confidence interval, 0.41-0.79). The association of muscle strength with AD persisted after adjustment for several covariates, including body mass index, physical activity, pulmonary function, vascular risk factors, vascular diseases, and apolipoprotein E4 status. In a mixed-effects model adjusted for age, sex, education status, and baseline level of global cognition, increased muscle strength was associated with a slower rate of decline in global cognitive function (P < .001). Muscle strength was associated with a decreased risk of MCI, the precursor to AD (hazard ratio, 0.67; 95% confidence interval, 0.54-0.84). These findings suggest a link between muscle strength, AD, and cognitive decline in older persons.

Mild Cognitive Impairment: Clinical Characterization and Outcome

Article

Full-text available

Apr 1999
ARCH NEUROL-CHICAGO

Subjects with a mild cognitive impairment (MCI) have a memory impairment beyond that expected for age and education yet are not demented. These subjects are becoming the focus of many prediction studies and early intervention trials. To characterize clinically subjects with MCI cross-sectionally and longitudinally. A prospective, longitudinal inception cohort. General community clinic. A sample of 76 consecutively evaluated subjects with MCI were compared with 234 healthy control subjects and 106 patients with mild Alzheimer disease (AD), all from a community setting as part of the Mayo Clinic Alzheimer's Disease Center/Alzheimer's Disease Patient Registry, Rochester, Minn. The 3 groups of individuals were compared on demographic factors and measures of cognitive function including the Mini-Mental State Examination, Wechsler Adult Intelligence Scale-Revised, Wechsler Memory Scale-Revised, Dementia Rating Scale, Free and Cued Selective Reminding Test, and Auditory Verbal Learning Test. Clinical classifications of dementia and AD were determined according to the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition and the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria, respectively. The primary distinction between control subjects and subjects with MCI was in the area of memory, while other cognitive functions were comparable. However, when the subjects with MCI were compared with the patients with very mild AD, memory performance was similar, but patients with AD were more impaired in other cognitive domains as well. Longitudinal performance demonstrated that the subjects with MCI declined at a rate greater than that of the controls but less rapidly than the patients with mild AD. Patients who meet the criteria for MCI can be differentiated from healthy control subjects and those with very mild AD. They appear to constitute a clinical entity that can be characterized for treatment interventions.

Cortisol levels during human aging predict hippocampal atrophy and memory deficits

Article

Full-text available

Jun 1998

Elevated glucocorticoid levels produce hippocampal dysfunction and correlate with individual deficits in spatial learning in aged rats. Previously we related persistent cortisol increases to memory impairments in elderly humans studied over five years. Here we demonstrate that aged humans with significant prolonged cortisol elevations showed reduced hippocampal volume and deficits in hippocampus-dependent memory tasks compared to normal-cortisol controls. Moreover, the degree of hippocampal atrophy correlated strongly with both the degree of cortisol elevation over time and current basal cortisol levels. Therefore, basal cortisol elevation may cause hippocampal damage and impair hippocampus-dependent learning and memory in humans.

Physical Activity and Risk of Cognitive Impairment and Dementia in Elderly Persons

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Apr 2001
ARCH NEUROL-CHICAGO

Dementia is common, costly, and highly age related. Little attention has been paid to the identification of modifiable lifestyle habits for its prevention. To explore the association between physical activity and the risk of cognitive impairment and dementia. Data come from a community sample of 9008 randomly selected men and women 65 years or older, who were evaluated in the 1991-1992 Canadian Study of Health and Aging, a prospective cohort study of dementia. Of the 6434 eligible subjects who were cognitively normal at baseline, 4615 completed a 5-year follow-up. Screening and clinical evaluations were done at both waves of the study. In 1996-1997, 3894 remained without cognitive impairment, 436 were diagnosed as having cognitive impairment-no dementia, and 285 were diagnosed as having dementia. Incident cognitive impairment and dementia by levels of physical activity at baseline. Compared with no exercise, physical activity was associated with lower risks of cognitive impairment, Alzheimer disease, and dementia of any type. Significant trends for increased protection with greater physical activity were observed. High levels of physical activity were associated with reduced risks of cognitive impairment (age-, sex-, and education-adjusted odds ratio, 0.58; 95% confidence interval, 0.41-0.83), Alzheimer disease (odds ratio, 0.50; 95% confidence interval, 0.28-0.90), and dementia of any type (odds ratio, 0.63; 95% confidence interval, 0.40-0.98). Regular physical activity could represent an important and potent protective factor for cognitive decline and dementia in elderly persons.

Plasma Homocysteine as a Risk Factor for Dementia and Alzheimer's Disease

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Mar 2002
NEW ENGL J MED

In cross-sectional studies, elevated plasma homocysteine levels have been associated with poor cognition and dementia. Studies of newly diagnosed dementia are required in order to establish whether the elevated homocysteine levels precede the onset of dementia or result from dementia-related nutritional and vitamin deficiencies. A total of 1092 subjects without dementia (667 women and 425 men; mean age, 76 years) from the Framingham Study constituted our study sample. We examined the relation of the plasma total homocysteine level measured at base line and that measured eight years earlier to the risk of newly diagnosed dementia on follow-up. We used multivariable proportional-hazards regression to adjust for age, sex, apolipoprotein E genotype, vascular risk factors other than homocysteine, and plasma levels of folate and vitamins B12 and B6. Over a median follow-up period of eight years, dementia developed in 111 subjects, including 83 given a diagnosis of Alzheimer's disease. The multivariable-adjusted relative risk of dementia was 1.4 (95 percent confidence interval, 1.1 to 1.9) for each increase of 1 SD in the log-transformed homocysteine value either at base line or eight years earlier. The relative risk of Alzheimer's disease was 1.8 (95 percent confidence interval, 1.3 to 2.5) per increase of 1 SD at base line and 1.6 (95 percent confidence interval, 1.2 to 2.1) per increase of 1 SD eight years before base line. With a plasma homocysteine level greater than 14 micromol per liter, the risk of Alzheimer's disease nearly doubled. An increased plasma homocysteine level is a strong, independent risk factor for the development of dementia and Alzheimer's disease.

Homocysteine and Lipoprotein Levels Following Resistance Training in Older Adults

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Oct 2003

This investigation examined the effect of 6 months of high- or low-intensity resistance exercise on serum homocysteine and lipoprotein (a) levels in adults aged 60-80 years. Forty-three men and women completed the study protocol. Subjects were randomly assigned to a control (n=10), low-intensity (LEX, n=18), or high-intensity (HEX, n=15) group. Subjects performed 6 months of resistance training at either 50% of their one-repetition maximum for 13 repetitions (LEX) or 80% of one-repetition maximum for eight repetitions (HEX) 3 times per week for 24 weeks. The load was increased by 5% when their rating of perceived exertion dropped below 18. One-repetition maximum; serum homocysteine; lipoprotein (a); total and high-density lipoprotein cholesterol; and dietary intake of vitamins B12, B6, and folic acid were measured pre- and poststudy. Upper and lower body strength significantly (p<0.05) increased for the LEX and HEX groups. Serum homocysteine decreased 5.30% and 5.34% for the LEX and HEX groups, respectively (p<0.05), but increased 6.1% for the control group. A significant increase in lipoprotein (a) levels was noted in the control and LEX groups from pre- to poststudy. No significant differences were noted either pre- or poststudy for total and high-density lipoprotein cholesterol or any dietary variables. These data indicate that significant reductions in serum levels of homocysteine in the elderly can be derived from resistance exercise training.

Walking and Dementia in Physically Capable Elderly Men

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Oct 2004
J Am Med Assoc

Evidence suggests that physical activity may be related to the clinical expression of dementia. Whether the association includes low-intensity activity such as walking is not known. To examine the association between walking and future risk of dementia in older men. Prospective cohort study. Distance walked per day was assessed from 1991 to 1993 in 2257 physically capable men aged 71 to 93 years in the Honolulu-Asia Aging Study. Follow-up for incident dementia was based on neurological assessment at 2 repeat examinations (1994-1996 and 1997-1999). Overall dementia, Alzheimer disease, and vascular dementia. During the course of follow-up, 158 cases of dementia were identified (15.6/1000 person-years). After adjusting for age, men who walked the least (<0.25 mile/d) experienced a 1.8-fold excess risk of dementia compared with those who walked more than 2 mile/d (17.8 vs 10.3/1000 person-years; relative hazard [RH], 1.77; 95% confidence interval [CI], 1.04-3.01). Compared with men who walked the most (>2 mile/d), an excess risk of dementia was also observed in those who walked 0.25 to 1 mile/d (17.6 vs 10.3/1000 person-years; RH, 1.71; 95% CI, 1.02-2.86). These associations persisted after accounting for other factors, including the possibility that limited amounts of walking could be the result of a decline in physical function due to preclinical dementia. Findings suggest that walking is associated with a reduced risk of dementia. Promoting active lifestyles in physically capable men could help late-life cognitive function.

Hormonal Responses and Adaptations to Resistance Exercise and Training

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Feb 2005

Resistance exercise has been shown to elicit a significant acute hormonal response. It appears that this acute response is more critical to tissue growth and remodelling than chronic changes in resting hormonal concentrations, as many studies have not shown a significant change during resistance training despite increases in muscle strength and hypertrophy. Anabolic hormones such as testosterone and the superfamily of growth hormones (GH) have been shown to be elevated during 15-30 minutes of post-resistance exercise providing an adequate stimulus is present. Protocols high in volume, moderate to high in intensity, using short rest intervals and stressing a large muscle mass, tend to produce the greatest acute hormonal elevations (e.g. testosterone, GH and the catabolic hormone cortisol) compared with low-volume, high-intensity protocols using long rest intervals. Other anabolic hormones such as insulin and insulin-like growth factor-1 (IGF-1) are critical to skeletal muscle growth. Insulin is regulated by blood glucose and amino acid levels. However, circulating IGF-1 elevations have been reported following resistance exercise presumably in response to GH-stimulated hepatic secretion. Recent evidence indicates that muscle isoforms of IGF-1 may play a substantial role in tissue remodelling via up-regulation by mechanical signalling (i.e. increased gene expression resulting from stretch and tension to the muscle cytoskeleton leading to greater protein synthesis rates). Acute elevations in catecholamines are critical to optimal force production and energy liberation during resistance exercise. More recent research has shown the importance of acute hormonal elevations and mechanical stimuli for subsequent up- and down-regulation of cytoplasmic steroid receptors needed to mediate the hormonal effects. Other factors such as nutrition, overtraining, detraining and circadian patterns of hormone secretion are critical to examining the hormonal responses and adaptations to resistance training.

Mediation of Cognitive Function Improvements by Strength Gains After Resistance Training in Older Adults with Mild Cognitive Impairment: Outcomes of the Study of Mental and Resistance Training

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