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Miyachi M.,National Institute of Health and Nutrition
British Journal of Sports Medicine | Year: 2013

Background Regular aerobic exercise prevents and reverses arterial stiffening, but the association between resistance training and arterial stiffness is unclear. Aim This study was performed to conduct a systematic review and meta-analysis of randomised controlled clinical trials (RCTs) assessing the associations between resistance training and changes in arterial stiffness. Methods MEDLINE and SPORTDiscus databases were searched from January 1980 through to April 2011. RCTs evaluating the ability of resistance training to increase arterial stiffness in comparison with a control group were included in the meta-analysis. Two independent reviewers extracted data and assessed the quality of the included studies. Data from 185 reports of eight RCTs (193 participants) were included. Pooled mean differences in arterial stiffness indices (carotid arterial â stiffness and pulse wave velocity (PWV)) between intervention and control groups were calculated using a random-effects model. Results The overall association of resistance training versus control with relative changes in carotid â index or PWV (eight studies; 193 participants) was 10.7% (95% CI 3.4% to 18.0%; I2, 89%; heterogeneity, p<0.001). Five studies indicated that resistance training in young subjects (n=115) was significantly associated with an increase in stiffness index of 14.3% (95% CI 8.5% to 20.1%; I2, 71%; heterogeneity, p<0.001) compared with controls. However, three studies showed that resistance training in middle-aged subjects (n=78) was not associated with changes in arterial stiffness. In addition, although high-intensity resistance training (n=87) was significantly associated with an increase in stiffness of 11.6%, moderate-intensity resistance training (n=106) showed no such association. Conclusion High-intensity resistance training is associated with increased arterial stiffness in young subjects with low baseline levels of arterial stiffness. Source

Park W.,University of Texas at Austin | Miyachi M.,National Institute of Health and Nutrition | Tanaka H.,University of Texas at Austin
Journal of Clinical Hypertension | Year: 2014

The largest percentage of mortality from tobacco smoking is cardiovascular-related. It is not known whether regular participation in exercise mitigates the adverse influence of smoking on vasculature. Accordingly, the authors determined whether regular aerobic exercise is associated with reduced arterial stiffness in men who smoke cigarettes. Using a cross-sectional study design, 78 young men were studied, including sedentary nonsmokers (n=20), sedentary smokers (n=12), physically active nonsmokers (n=21), and physically active smokers (n=25). Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV). There were no group differences in height, body fat, and systolic and diastolic blood pressure. As expected, both physically active groups demonstrated greater maximal oxygen consumption and lower heart rate at rest than their sedentary peers. The sedentary smokers demonstrated greater baPWV than the sedentary nonsmokers (11.8±1 m/s vs 10.6±1 m/s, P=.036). baPWV values were not different between the physically active nonsmokers and the physically active smokers (10.8±1 m/s vs 10.7±1 m/s). Chronic smoking is associated with arterial stiffening in sedentary men but a significant smoking-induced increase in arterial stiffness was not observed in physically active adults. These results are consistent with the idea that regular participation in physical activity may mitigate the adverse effects of smoking on the vasculature. ©2014 Wiley Periodicals, Inc. Source

Tanaka N.I.,National Institute of Health and Nutrition | Kanehisa H.,National Institute of Fitness and Sports in Kanoya
International Journal of Sports Medicine | Year: 2014

The present study aimed to evaluate the applicability of using a single slice cross-sectional area (CSA) of the skeletal muscle for estimating segmental skeletal muscle volume (SMV). By using MRI, the SMV of each of the upper arm, lower arm, upper leg, lower leg, and trunk was determined in 29 males. First, step-wise multiple regression analysis was applied to develop the equation for each segmental SMV in which the CSAs at intervals of 10% of segment length (SL) were used as independent variables. Second, simple linear regression analysis with every CSA selected in the first step was applied to predict SMV in each body segment. In each segment, the standard error of estimate (SEE) in the simple linear regression equation was greater than that in the multiple regression one. The most appropriate slice level for measuring a single CSA to estimate SMV was 30% of the upper arm SL (R2=0.800, SEE=7.4%), 60% of the lower arm SL (0.788, 10.3%), 50% of the upper leg SL (0.795, 7.0%), and 20% of the trunk SL (0.813, 6.1%). For the lower leg, muscle CSAs at multiple slice levels are required to estimate SMV without the systematic error. © 2014 Georg Thieme Verlag KG Stuttgart New York. Source

Murakami H.,National Institute of Health and Nutrition
[Nihon kōshū eisei zasshi] Japanese journal of public health | Year: 2013

This study was performed to assess the validity and reproducibility of a questionnaire on physical activity status used for health surveying among victims of the Great East Japan Earthquake. Seventy-four residents (21 men and 53 women) living in temporary housing in Kamaishi City, Iwate Prefecture, participated in this study. The physical activity status questionnaire was composed of 4 questions regarding the frequency of performing domestic and occupational physical activities, the frequency of leaving their residence, walking duration per day, and sedentary time. The physical activity level for 2 weeks was measured using a tri-accelerometer to validate the responses to the questionnaire. Test-retest reproducibility was examined at 2-week intervals. The physical activity levels were 4,521 +/- 2,266 steps/day for men and 4,533 +/- 2,070 steps/day for women. There was a significant difference in step count between those responding differently to the 3 options in the questionnaire regarding average walking duration per day: those who reported walking for > or = 60 min, 30-60 min, or < or = 30 min had step counts of 5,343 +/- 1,757, 4,760 +/- 1,752, and 3,063 +/- 1,772 steps/day, respectively (P < 0.05). When the response options for 3 questions (excluding those for sedentary time) were given scores (a higher score for a higher physical activity level), there were significant correlations between question score and step count (r = 0.486, P < 0.05) and the amount of moderate to vigorous physical activity (r = 0.342, P < 0.05). The test-retest trial showed a moderate degree of reproducibility, with weighted K coefficients of 0.41-0.65. Three questions on physical activity levels may allow assessment of an individual's physical activity level, with a moderate degree of reproducibility. Source

Murakami H.,National Institute of Health and Nutrition
[Nihon kōshū eisei zasshi] Japanese journal of public health | Year: 2014

This study investigated the longitudinal changes in the physical activity of the Great East Japan Earthquake victims living in temporary housing. Thirty-nine residents (10 men and 29 women) living in temporary housing in Kamaishi City, Iwate Prefecture, participated in a health survey in 2012. Among these residents, 31 who also participated in a health survey in 2011 were included in a longitudinal study of physical activity. The physical activity for two weeks after the health survey was measured using a tri-accelerometer. During the one-year period from 2011 to 2012, the median daily step counts changed from 4,959 (interquartile range: 2,910-6,029) steps/day to 4,618 (interquartile range: 3,007-7,123) steps/day. The step counts increased for 18 people (56%). The amount of moderate to vigorous physical activity changed from 13.3 (interquartile range: 7.7-22.4) METs h/week to 16.1 (interquartile range: 6.3-25.2) METs h/week. An increase in daily step counts occurred for 14 out of 21 subjects who were <65 years old (67%) and only 3 out of 10 subjects who were ≥65 years old (30%). It was suggested that physical activity levels increased because the interquartile range of step counts moved in the direction of an increase and the median amount of moderate to vigorous physical activity increased. However, increasing support for physical activity in the future is required because the physical activity levels of the Great East Japan Earthquake victims who were living in temporary housing were still low compared to the national and regional averages. Source

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