Investigating dose–response effects of multimodal exercise programs on health-related quality of life in older adults

Navin Kaushal,1,2 Francis Langlois,3 Laurence Desjardins-Crépeau,1,2,4 Martin S Hagger,5,6 Louis Bherer1,2,4 1Department of Medicine, University of Montreal, Montreal, Quebec, Canada; 2Research Center, Montreal Heart Institute, Montreal, Quebec, Canada; 3CIUSSS de l’Estrie, Centre Hospitalier Universitaire de Sherbrooke, Montreal, Quebec, Canada; 4Research Center, Geriatrics Institute, University of Montreal, Montreal, Quebec, Canada; 5School of Psychology and Speech Pathology, Faculty of Health Sciences, Curtin University, Perth, WA, Australia; 6Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland Background: Older adults are at risk of multiple chronic diseases, most of which could be prevented by engaging in regular physical activity. Frailty is a state of increased vulnerability to diseases. Worsening symptoms of frailty, such as decrease in physical functionality, can compromise health-related quality of life (HR-QOL). Previous findings suggest that frailty moderates the relationship between physical activity and HR-QOL, yet intervention findings are limited, particularly in dose–response analyses. Hence, this study was conducted to test if lower-dose physical activity (120 minutes/week) would provide the same benefits in health outcomes (physical functionality and HR-QOL) as higher-dose physical activity (180 minutes/week).Methods: Participants (n=110) were older adults comprising higher-dose, lower-dose, and control groups who were combined from recent randomized controlled trials. Experimental groups participated in a multimodal exercise program in a supervised laboratory setting for 12 weeks.Results: The higher-dose group showed a significant improvement in physical functionality (β=0.23, P=0.03) and in overall HR-QOL (β=0.44, P=0.001) including its subcategories over the control group. A group × frailty interaction revealed that frail individuals significantly improved in capacity HR-QOL when they exercised at a higher dose (F (1, 49)=4.57, P=0.038).Conclusion: This study identifies a positive, predictive relationship between exercise duration and health outcomes (HR-QOL dimensions and frailty) among older adults. Frail individuals in the higher-dose group demonstrated significant recovery of capacity HR-QOL, thus reflecting improvement in their daily activities. Keywords: physical activity, aging, multimodal exercise, frailt

Effects of combined physical and cognitive training on fitness and neuropsychological outcomes in healthy older adults

Laurence Desjardins-Crépeau,1,2 Nicolas Berryman,2,3 Sarah A Fraser,4 Thien Tuong Minh Vu,5,6 Marie-Jeanne Kergoat,2,6 Karen ZH Li,7 Laurent Bosquet,8 Louis Bherer2,7 1Department of Psychology, University of Quebec at Montreal, Montreal, QC, Canada; 2Research Center, Institut universitaire de gériatrie de Montréal, Montreal, QC, Canada; 3Department of Sports Studies, Bishop’s University, Sherbrooke, QC, Canada; 4Interdisciplinary School of Health Sciences, University of Ottawa, Ottawa, ON, Canada; 5Research Center, Centre hospitalier de l’Université de Montréal, Montreal, QC, Canada; 6Faculty of Medicine, Université de Montréal, Montreal, QC, Canada; 7Department of Psychology and PERFORM Centre, Concordia University, Montréal, QC, Canada; 8Faculté des sciences du sport, Université de Poitiers, Poitiers, France Purpose: Physical exercise and cognitive training have been shown to enhance cognition among older adults. However, few studies have looked at the potential synergetic effects of combining physical and cognitive training in a single study. Prior trials on combined training have led to interesting yet equivocal results. The aim of this study was to examine the effects of combined physical and cognitive interventions on physical fitness and neuropsychological performance in healthy older adults.Methods: Seventy-six participants were randomly assigned to one of four training combinations using a 2×2 factorial design. The physical intervention was a mixed aerobic and resistance training program, and the cognitive intervention was a dual-task (DT) training program. Stretching and toning exercises and computer lessons were used as active control conditions. Physical and cognitive measures were collected pre- and postintervention.Results: All groups showed equivalent improvements in measures of functional mobility. The aerobic–strength condition led to larger effect size in lower body strength, independently of cognitive training. All groups showed improved speed of processing and inhibition abilities, but only participants who took part in the DT training, independently of physical training, showed increased task-switching abilities. The level of functional mobility after intervention was significantly associated with task-switching abilities.Conclusion: Combined training did not yield synergetic effects. However, DT training did lead to transfer effects on executive performance in neuropsychological tests. Both aerobic-resistance training and stretching-toning exercises can improve functional mobility in older adults. Keywords: aging, combined intervention, physical performance, cognitive performance, dual task, executive function

Higher cardiovascular fitness level is associated with lower cerebrovascular reactivity and perfusion in healthy older adults

Aging is accompanied by vascular and structural changes in the brain, which include decreased grey matter volume (GMV), cerebral blood flow (CBF), and cerebrovascular reactivity (CVR). Enhanced fitness in aging has been related to preservation of GMV and CBF, and in some cases CVR, although there are contradictory relationships reported between CVR and fitness. To gain a better understanding of the complex interplay between fitness and GMV, CBF and CVR, the present study assessed these factors concurrently. Data from 50 participants, aged 55 to 72, were used to derive GMV, CBF, CVR and VO2peak. Results revealed that lower CVR was associated with higher VO2peak throughout large areas of the cerebral cortex. Within these regions lower fitness was associated with higher CBF and a faster hemodynamic response to hypercapnia. Overall, our results indicate that the relationships between age, fitness, cerebral health and cerebral hemodynamics are complex, likely involving changes in chemosensitivity and autoregulation in addition to changes in arterial stiffness. Future studies should collect other physiological outcomes in parallel with quantitative imaging, such as measures of chemosensitivity and autoregulation, to further understand the intricate effects of fitness on the aging brain, and how this may bias quantitative measures of cerebral health

Obese but Fit: The Benefits of Fitness on Cognition in Obese Older Adults.

Obesity is associated with an accelerated cognitive decline. Aerobic fitness has a protective effect on cognition in older adults, but no study has investigated this effect in obese individuals. The present study aimed to 1) compare cognitive function in lower-fit (LoFit) and higher-fit (HiFit) obese individuals compared with nonobese individuals, and 2) examine the association between exercise variables (including hemodynamic variables) and cognitive function in obese individuals. Fifty-four obese and 16 nonobese individuals performed a maximal cardiopulmonary exercise test (with gas exchange analysis and noninvasive hemodynamic measurement) and cognitive tests assessing short-term and working memory, processing speed, executive function, and long-term verbal memory. Obese individuals were divided into 2 groups according to their median aerobic fitness divided by lean body mass to form a group of LoFit obese (n = 27) and a group of HiFit obese (n = 27) individuals. A total of 14 nonobese individuals and 49 obese individuals were included in the final analysis (HiFit: n = 26, LoFit: n = 23). Compared with LoFit obese, HiFit obese participants had greater performances in executive function (P = 0.002) and short-term memory (P = 0.02). Nonobese and HiFit obese participants showed equivalent performances in all domains of cognition. In obese individuals, aerobic fitness was the only independent predictor for short-term memory (R <sup>2</sup> = 0.24; P < 0.001), working memory (R <sup>2</sup> = 0.16; P = 0.02), processing speed (R <sup>2</sup> = 0.22; P = 0.01), and executive function (R <sup>2</sup> = 0.49; P = 0.003), but not for long-term verbal memory (R <sup>2</sup> = 0.15; P = 0.26). HiFit obese individuals showed greater short-term memory and executive function performances compared with LoFit obese individuals, suggesting that aerobic fitness could help preserve cognitive function despite the presence of obesity