Sungchul Lee

Relationship between Physical Activity and Brain Atrophy Progression.

INTRODUCTION Brain atrophy is associated with impairment in cognitive function and learning function. The aim of this study was to determine whether daily physical activity prevents age-related brain atrophy progression. METHODS The participants were 381 men and 393 women who had participated in both the baseline and the follow-up surveys (mean duration = 8.2 yr). Magnetic resonance imaging of the frontal and temporal lobes was performed at the time of the baseline and follow-up surveys. The daily physical activities and total energy expenditures of the participants were recorded at baseline with uniaxial accelerometry sensors. Multiple logistic regression models were fit to determine the association between activity energy expenditure, number of steps, and total energy expenditure variables and frontal and temporal lobe atrophy progression while controlling for possible confounders. RESULTS In male participants, the odds ratio of frontal lobe atrophy progression for the fifth quintile compared with the first quintile in activity energy expenditure was 3.408 (95% confidence interval = 1.205-9.643) and for the number of steps was 3.651 (95% confidence interval = 1.304-10.219). Men and women with low total energy expenditure were at risk for frontal lobe atrophy progression. There were no significant differences between temporal lobe atrophy progression and physical activity or total energy expenditure. CONCLUSION The results indicate that physical activity and total energy expenditure are significant predictors of frontal lobe atrophy progression during an 8-yr period. Promoting participation in activities may be beneficial for attenuating age-related frontal lobe atrophy and for preventing dementia.

Research Relationship Between Light‐Intensity Physical Activity and Cognitive Function in a Community‐Dwelling Elderly Population—An 8‐Year Longitudinal Study

To the Editor: There is considerable evidence suggesting the beneficial effects of moderate to vigorous physical activity (MVPA) and the negative effects of sedentary behavior on health outcomes. A meta-analysis of 15 prospective studies showed a significant inverse relationship between high levels of physical activity and risk of cognitive decline in cognitively normal older adults, but the contribution of light-intensity physical activity and sedentary time to cognitive function is less well known. Light-intensity physical activity, which includes activities such as washing dishes, ironing, and other routine domestic or occupational tasks, is the predominant determinant of variability in total daily energy expenditure. Light-intensity physical activity is particularly important for older adults because they tend to spend a greater portion of their day performing light-intensity physical activity than any other age group. The purpose of the present study was to examine the relationship between light-intensity physical activity and sedentary time and cognitive decline independent of MVPA in a community-dwelling population aged 60 and older. Participants were 550 (289 men, 261 women) adults aged 60 and older who completed the second (April 2000 to May 2002) and sixth (April 2008 to May 2010) wave of examinations of the National Institute for Longevity Sciences —Longitudinal Study of Aging (NILS-LSA) in Aichi, Japan. Trained interviewers asked subjects about time spent in physical activity for the past 12 months using a questionnaire developed by the Japanese Lifestyle Monitoring Study Group. The questionnaire captured the duration of lightintensity physical activity, MVPA, and sedentary time determined by metabolic equivalent (MET) scores (a multiple of the resting metabolic rate) reported in the literature. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). A decline of at least three points in MMSE score from baseline to follow-up was considered meaningful from a clinical point of view. Education level (>9, 9 yr), smoking status (current, former, never), occupation (working or not), depressive symptoms (Center for Epidemiologic Studies Depression

Effects of Hydraulic-resistance Exercise on Strength and Power in Untrained Healthy Older Adults

Lee, S, Islam, MM, Rogers, ME, Kusunoki, M, Okada, A, and Takeshima, N. Effects of hydraulic-resistance exercise on strength and power in untrained healthy older adults. J Strength Cond Res 25(4): 1089-1097, 2011-The purpose of this study was to determine the efficacy of hydraulic-resistance exercise (HDRE) in improving strength and power in healthy older adults. Thirty-nine older adults (68.6 ± 4.9 years; 15 men, 24 women) were divided into a training group or control group (CON). Hydraulic-resistance exercise consisted of a 12-week supervised program, 50 min·d−1, 3 d·wk−1. Hydraulic-resistance exercise was used for 10 exercises: Chest press and pull, shoulder press and pull, low back flexion and extension squat, leg adduction/abduction, leg press, and elbow extension/flexion. The number of the sets and the hydraulic-resistance dial setting (D) were gradually increased in 3 stages during the 12-week program. Strength, rating of perceived exertion, and relative intensity during exercise increased significantly from stage to stage whereas repetition velocity decreased. Total work was higher in the second stage compared with the first but lower in the final stage because of reduced repetitions. Peak torque at D2 and D11 increased (p < 0.05) for knee extension (58 and 9%) and flexion (94 and 21%), chest press (35 and 12%) and pull (29 and 14%), shoulder press (14 and 18%) and pull (75 and 18%), and low back flexion (59 and 46%) and extension (84 and 34%). Peak power at D2 and D11 also increased (p < 0.05) for knee extension (140 and 26%) and flexion (96 and 36%), chest press (54 and 28%) and pull (62 and 23%), shoulder press (55 and 31%) and pull (159 and 30%), and low back flexion (177 and 127%) and extension (104 and 66%). There were no significant changes in the CON. Hydraulic-resistance exercise elicits significant improvements in strength and power in older adults. Therefore, HDRE is an effective form of resistance training that provides benefits using low and moderate intensity of training for older adults.