Search

Aims/introduction: To investigate the relationship between combined aerobic and resistance training, and the incidence of type 2 diabetes mellitus., Materials and Methods: The present study included 10,680 Japanese women. Participants enrolled between 2005 and 2010, and were followed up until 2014. The frequency of combined training was counted for the first 3 months, the 6th month and the 9th month. In 2014, women reported whether or not they had diabetes, as well as the year of developing diabetes. Hazard ratios and 95% confidence intervals (CI) for the incidence of type 2 diabetes were obtained using Cox proportional hazard models., Results: The median duration of follow up was 5 years, with 166 women developing type 2 diabetes. Using the lowest frequency of training group (1st quartile) as the reference, the hazard ratios for the second through fourth quartiles was as follows: 0.95 (95% CI 0.64-1.41), 0.73 (95% CI 0.48-1.13) and 0.69 (95% CI 0.44-1.07), respectively (P for trend = 0.116). After adjustment for age, body mass index and thigh circumference, the hazard ratios were: 0.84 (95% CI 0.56-1.26), 0.69 (95% CI 0.45-1.06) and 0.61 (95% CI 0.39-0.95), respectively (P for trend = 0.040)., Conclusions: A higher frequency of combined aerobic and resistance training is associated with a lower risk of developing type 2 diabetes in Japanese women., (© 2018 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.)

Current physical activity (PA) guidelines indicate that moderate-intensity (MPA) and vigorous intensity (VPA) PA provide similar benefits when total volume is equal. The present study examined the associations of MPA and VPA with body composition and cardiorespiratory fitness in free-living young adults. A total of 197 young adults (52.8 % male) were followed over a period of 15 months. Body composition was assessed via dual X-ray absorptiometry and time spent in various PA intensities was determined with a multi-sensor device every 3 months. Cardiorespiratory fitness was assessed with a graded exercise test at baseline and 15-months follow-up. Change in VPA was positively associated with cardiorespiratory fitness while MPA had beneficial associations with percent body fat. In overweight/obese participants the association with VO2peak was similar for MVPA bouts and VPA. Even though MPA and VPA have positive associations with overall health, their associations on key health parameters differ.

We examined the association of body composition and body mass index (BMI) with submaximal systolic blood pressure (SSBP) among young adult men. The analysis included 211 men with BMI between 20 and 35 kg/m(2). Total lean mass and fat mass were measured using dual x-ray absorptiometry and lean mass percentage was calculated from the total lean mass. Fat mass index (FMI) and BMI were calculated using height and weight (total fat mass and total weight, respectively) measurements. SSBP was measured at each stage of a graded exercise test. Quintiles of lean mass percentage, FMI, and BMI were created with quintile 1 the lowest and quintile 5 the highest lean mass percentage, FMI, and BMI. Compared with men in lean mass percentage quintile 1, those in quintiles 2, 3, and 4 had significantly lower SSBP, whereas there was no significant difference in SSBP between quintile 1 and 5 at 6, 8, and 10 minutes. Compared with men in FMI quintile 5, those in quintiles 2, 3, and 4 had significantly lower SSBP, whereas there was no significant difference in SSBP between quintile 1 and 5. SSBP among men in lean mass percentage quintile 5 and FMI quintile 1 were still less than lean mass percentage quintile 1 and FMI quintile 5, respectively. There were no significant differences in SSBP across BMI quintiles 1 to 4 but a significantly higher SSBP in quintile 5 compared with quintiles 1 to 4. In conclusion, there was a J-curve pattern between SSBP and components of body composition, whereas, a linear relation between SSBP and BMI., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: In Japan, the incidence of kidney stones has increased markedly in recent decades. Major causes of kidney stones remain unclear, and limited data are available on the relationship between overweight/obesity and the incidence of kidney stones. We therefore evaluated body mass index (BMI) and the incidence of kidney stones in Japanese men., Methods: Of the workers at a gas company, 5984 males aged 20-40 years underwent a medical examination in 1985 (baseline). This study includes 4074 of the men, who were free of kidney stones at baseline and underwent a second medical examination performed between April 2004 and March 2005. BMI was calculated from measured height and weight in 1985, and men were categorized into tertiles. The development of kidney stones during follow-up was based on self-reports from questionnaires at the second medical examination., Results: The average duration of follow-up was 19 years, with 258 participants developing kidney stones during this period. Using the lowest BMI (1st tertile) group as a reference, the hazard ratios (95% confidence intervals [CIs]) for the 2nd and 3rd BMI tertiles were: 1.26 (95% CI, 0.92-1.73) and 1.44 (95% CI, 1.06-1.96), respectively (P for trend = 0.019). After additionally adjusting for potential confounders, such as age, systolic blood pressure, cardiorespiratory fitness, cigarette smoking, and alcohol consumption, the hazard ratios were 1.28 (95% CI, 0.93-1.76) and 1.41 (95% CI, 1.02-1.97), respectively (P for trend = 0.041)., Conclusions: These results suggest that increased BMI is a risk factor for kidney stones in Japanese men.

Purpose: Physical activity and body mass index (BMI) are involved in prostate cancer etiology; possible biologic mechanisms include their effects on hormonal levels. Our aim was to investigate the relationship between physical activity, obesity, and prostate cancer., Methods: We followed a cohort of 13,109 Swedish men for 13 years and investigated the association of self-reported physical activity and BMI at baseline with prostate cancer incidence. We further analyzed whether BMI could modulate effects of physical activity. Occupational, recreational, and total physical activity were analyzed in relation to overall, localized, and advanced prostate cancer., Results: During the study follow-up, we observed a total of 904 cases of prostate cancer (429 localized, 407 advanced, and 68 unclassified). High levels of occupational physical activity were associated with a nonsignificantly decreased risk of overall (HR 0.81, 95 % CI 0.61-1.07), localized (HR 0.75, 95 % CI 0.51-1.12), and advanced (HR 0.85, 95 % CI 0.55-1.31) prostate cancer. We found no association between high BMI and risk of prostate cancer incidence: We observed, however, a significant interaction between BMI and leisure physical activity., Conclusion: No association was confirmed between total physical activity and localized or advanced prostate cancer. The highest, relative to the lowest, level of occupational physical activity tended to be linked to a lower risk of prostate cancer, with a suggested dose-response relationship. We found no association between high BMI and risk of prostate cancer incidence; however, our analyses suggested an interaction between BMI and physical activity during recreational time that merits further investigation in future studies.

Purpose: Determine if individuals with poor sleep characteristics (i.e., late sleep onset or wake times, short sleep duration, long sleep latency, low sleep efficiency, high wake after sleep onset) have greater body mass index (BMI = kg/m(2)) or body fat., Methods: Data for these cross-sectional analyses were from the Energy Balance Study (University of South Carolina). Participants were between 21 and 35 years of age and had a BMI of 20 to 35 kg/m(2). Body fat percent was measured by dual X-ray absorptiometry. Sleep and physical activity were measured by actigraphy (BodyMedia's SenseWear physical activity armband). General linear models were used to estimate mean BMI and body fat percent by sleep metric categories., Results: Greater BMI and body fat percent were associated with low sleep efficiency (BMI = 25.5 vs. 24.8 kg/m(2), P < .01; body fat = 27.7% vs. 26.5%, P = .04) and high wake after sleep onset (BMI = 25.6 vs. 25.0 kg/m(2), P = .02; body fat = 28.0% vs. 26.7%, P = .03). Elevated BMI or body fat percent also were observed for later wake times, shorter sleep duration, and longer sleep latency. Sex modified the association between wake times and body composition., Conclusions: Understanding the complex relationships between sleep and health outcomes could help reduce chronic disease burden by incorporating sleep components, measured through novel noninvasive techniques (SenseWear armband), into weight loss interventions., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objective: To investigate secular change of cardiorespiratory fitness (CRF) and body composition during 35 years in a large sample of women enrolled in the Aerobics Center Longitudinal Study., Patients and Methods: A cross-sectional analysis of baseline fitness data collected during preventive medical examination of 13,037 women aged 20 to 64 years evaluated at the Cooper Clinic in Dallas, Texas, from January 1, 1970, through December 30, 2004, who underwent a body composition assessment and a maximal treadmill exercise test. Women were stratified by examination year (5 years for each group) and age. Analysis of covariance was used to ascertain secular change of CRF and body composition., Results: Adjusted CRF levels, as indicated by maximal metabolic equivalent or relative maximum oxygen consumption, among women in the cohort increased significantly during a 35-year period for both age groups (P<.001). The greatest change occurred during the 1970s to 1980s, with a small decrease in 2000 through 2004 in both age groups. Adjusted body mass index increased 9.05% during the past 35 years (P<.001), but adjusted percentage of body fat was significantly higher in 1980 through 1984 than in the other groups (P<.001)., Conclusions: In a large cohort of women, the mean CRF has improved during the past 35 years, with a slight decrease in 2000 through 2004. From 1980 through 2004, the increase in body weight was mainly attributable to the increase in fat-free mass., (Copyright © 2015 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.)

Background: The aim of this study is to investigate the independent and joint effects of cardiorespiratory fitness (CRF) and body mass index (BMI) on cancer mortality in a low body mass index population., Methods: We evaluated CRF and BMI in relation to cancer mortality in 8760 Japanese men. The median BMI was 22.6 kg/m2 (IQR: 21.0-24.3). The mean follow-up period was more than 20 years. Hazard ratios and 95% CI were obtained using a Cox proportional hazards model while adjusting for several confounding factors., Results: Using the 2nd tertile of BMI (21.6-23.6 kg/m2) as reference, hazard ratios and 95% CI for the lowest tertile of BMI (18.5-21.5) were 1.26 (0.87-1.81), and 0.92 (0.64-1.34) for the highest tertile (23.7-37.4). Using the lowest tertile of CRF as reference, hazard ratios and 95% CIs for 2nd and highest tertiles of CRF were 0.78 (0.55-1.10) and 0.59 (0.40-0.88). We further calculated hazard ratios according to groups of men cross-tabulated by tertiles of CRF and BMI. Among men in the second tertile of BMI, those belonging to the lowest CRF tertile had a 53% lower risk of cancer mortality compared to those in the lowest CRF tertile (hazard ratio: 0.47, 95% CI: 0.23-0.97). Among those in the highest BMI tertile, the corresponding hazard ratio was 0.54 (0.25-1.17)., Conclusion: These results suggest that high CRF is associated with lower cancer mortality in a Japanese population of men with low average BMI.

The effects of overweight and obesity on chronic diseases, particularly on cardiovascular disease (CVD), and its impact on increasing CVD risk factors and total CVD are reviewed. However despite the adverse effects of obesity on CVD risk factors and CVD, obesity has a surprising association with prognosis in patients with established diseases, often showing an "obesity paradox," [corrected] where overweight (body mass index (BMI), 25 to 29.9 kg·m(-2)) and obese patients (BMI, ≥30 kg·m(-2)) with established CVD frequently have a better prognosis than that of their leaner counterparts (BMI, <25 kg·m(-2)) with the same diseases. Fitness-versus-fatness debate is summarized also, including the critical role that fitness plays to alter the relationship between adiposity and subsequent prognosis.

Background: High levels of obesity among African American women have been hypothesized to be partially resultant from a lower resting metabolic rate compared with white women. The aim of the current study was to determine if differences in cardiorespiratory fitness and moderate-to-vigorous physical activity are associated with differences in resting metabolic rate among free-living young adult African American women and white women., Methods: Participants were 179 women (white women n = 141, African American women n = 38, mean age = 27.7 years). Resting metabolic rate was measured using indirect calorimetry, body composition using dual energy x-ray absorptiometry, cardiorespiratory fitness via maximal treadmill test, and moderate-to-vigorous physical activity using an activity monitor., Results: African American women had higher body mass index, fat mass, and fat-free mass compared with white women but lower levels of cardiorespiratory fitness. No differences were observed between African American and white women in resting metabolic rate when expressed as kcal/day (1390.8 ± 197.5 vs 1375.7 ± 173.6 kcal/day, P = .64), but African American women had a lower resting metabolic rate when expressed relative to body weight (2.56 ± 0.30 vs 2.95 ± 0.33 mL/kg/min, P < .001). After statistical adjustment for differences in body composition between groups using linear regression models, African American women had a lower resting metabolic rate compared with white women (1299.4 ± 19.2 vs 1400.4 ± 9.2 kcal/day, P < .001). The addition of cardiorespiratory fitness reduced the differences among groups by 25%. The addition of moderate-to-vigorous physical activity did not improve the model., Conclusions: The present study confirms that African American women have a lower resting metabolic rate compared with their white peers, and low cardiorespiratory fitness explained 25% of this difference. Variables associated with resting metabolic rate, such as cardiorespiratory fitness, represent possible points of tailored interventions designed to address high levels of obesity seen in certain demographic groups., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objective: To examine associations among age, physical activity (PA), and birth cohort on body mass index (BMI) percentiles in men., Methods: Longitudinal analyses using quantile regression were conducted among men with ≥ two examinations between 1970 and 2006 from the Aerobics Center Longitudinal Study (n = 17,759). Height and weight were measured; men reported their PA and were categorized as inactive, moderately, or highly active at each visit. Analyses allowed for longitudinal changes in PA., Results: BMI was greater in older than younger men and in those born in 1960 than those born in 1940. Inactive men gained weight significantly more rapidly than active men. At the 10th percentile, increases in BMI among inactive, moderately active, and highly active men were 0.092, 0.078, and 0.069 kg/m(2) per year of age, respectively. The 10th percentile increased by 0.081 kg/m(2) per birth year and by 0.180 kg/m(2) at the 90th percentile, controlling for age., Conclusion: Although BMI increased with age, PA reduced the magnitude of the gradient among active compared to inactive men. Regular PA had an important, protective effect against weight gain. This study provides evidence of the utility of quantile regression to examine the specific causes of the obesity epidemic., (© 2013 The Obesity Society.)

Obesity has been increasing in epidemic proportions, with a disproportionately higher increase in morbid or class III obesity, and obesity adversely affects cardiovascular (CV) hemodynamics, structure, and function, as well as increases the prevalence of most CV diseases. Progressive declines in physical activity over 5 decades have occurred and have primarily caused the obesity epidemic. Despite the potential adverse impact of overweight and obesity, recent epidemiological data have demonstrated an association of mild obesity and, particularly, overweight on improved survival. We review in detail the obesity paradox in CV diseases where overweight and at least mildly obese patients with most CV diseases seem to have a better prognosis than do their leaner counterparts. The implications of cardiorespiratory fitness with prognosis are discussed, along with the joint impact of fitness and adiposity on the obesity paradox. Finally, in light of the obesity paradox, the potential value of purposeful weight loss and increased physical activity to affect levels of fitness is reviewed., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

The purpose of this study was to quantify the joint association of cardiorespiratory fitness (CRF) and weight status on mortality from all causes using meta-analytical methodology. Studies were included if they were (1) prospective, (2) objectively measured CRF and body mass index (BMI), and (3) jointly assessed CRF and BMI with all-cause mortality. Ten articles were included in the final analysis. Pooled hazard ratios were assessed for each comparison group (i.e. normal weight-unfit, overweight-unfit and -fit, and obese-unfit and -fit) using a random-effects model. Compared to normal weight-fit individuals, unfit individuals had twice the risk of mortality regardless of BMI. Overweight and obese-fit individuals had similar mortality risks as normal weight-fit individuals. Furthermore, the obesity paradox may not influence fit individuals. Researchers, clinicians, and public health officials should focus on physical activity and fitness-based interventions rather than weight-loss driven approaches to reduce mortality risk., (© 2013.)

Objective: To validate the PAR protocol, a novel method for calculating population-level estimated energy requirements (EERs) and average physical activity ratio (APAR), in a nationally representative sample of US adults., Methods: Estimates of EER and APAR values were calculated via a factorial equation from a nationally representative sample of 2597 adults aged 20 and 74 years (US National Health and Nutrition Examination Survey; data collected between January 1, 2005, and December 31, 2006). Validation of the PAR protocol-derived EER (EER(PAR)) values was performed via comparison with values from the Institute of Medicine EER equations (EER(IOM))., Results: The correlation between EER(PAR) and EER(IOM) was high (0.98; P<.001). The difference between EER(PAR) and EER(IOM) values ranged from 40 kcal/d (1.2% higher than EER(IOM)) in obese (body mass index [BMI] ≥30) men to 148 kcal/d (5.7% higher) in obese women. The 2005-2006 EERs for the US population were 2940 kcal/d for men and 2275 kcal/d for women and ranged from 3230 kcal/d in obese (BMI ≥30) men to 2026 kcal/d in normal weight (BMI <25) women. There were significant inverse relationships between APAR and both obesity and age. For men and women, the APAR values were 1.53 and 1.52, respectively. Obese men and women had lower APAR values than normal weight individuals (P¼.023 and P¼.015, respectively) [corrected], and younger individuals had higher APAR values than older individuals (P<.001)., Conclusion: The PAR protocol is an accurate method for deriving nationally representative estimates of EER and APAR values. These descriptive data provide novel quantitative baseline values for future investigations into associations of physical activity and health., (Copyright © 2013 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.)

Objective: To evaluate the association of body adiposity index (BAI) with all-cause and cardiovascular disease (CVD) mortality risk., Design and Methods: The current analysis comprised 19,756 adult men who enrolled in the Aerobics Centre Longitudinal Study and completed a baseline examination during 1988-2002. All-cause and CVD mortality was registered till December 31, 2003., Results: During an average follow-up of 8.3 years (163,844 man-years), 353 deaths occurred (101 CVD deaths). Age- and examination year-adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for all-cause mortality risk were higher for men with high values of BMI (HR = 1.63, 95% CI = 1.19-2.23), waist circumference (1.55, 1.22-1.96), and percentage of body fat (%BF) (1.36, 1.04-1.31), but not for men with high values of BAI (1.28, 0.98-1.66). The HRs for CVD mortality risks were higher for men with high values in all adiposity measures (HRs ranged from 1.73 to 2.06). Most of these associations, however, became nonsignificant after adjusting for multiple confounders including cardiorespiratory fitness., Conclusion: BAI is not a better predictor of all-cause and CVD mortality risk than BMI, waist circumference, or %BF., (Copyright © 2013 The Obesity Society.)

Objective: To assess the age-associated longitudinal trends in cardiorespiratory fitness (CRF), leisure-time physical activity (PA), and body mass index (BMI) across the lifespan in a cohort of adult women., Methods: The sample included 1467 women from the Aerobics Center Longitudinal Study who were 30-79 years old at baseline and had 3-22 health examinations between 1971 and 2006. CRF was quantified by maximal Balke treadmill exercise tests. The total metabolic equivalent-minutes/week of self-reported PA and measured BMI (kg/m(2)) were calculated., Results: The overall pattern of CRF decreased over time. After age 60 years, fitness level tended to decline rapidly. Women at age 50 had the highest PA level, which decreased after age 50 and plateaued at age 60. The overall pattern of BMI increased with age. However, after age 60 years the rate of increase in BMI became much slower. Adjusting for smoking, health status, and the individual exposures of CRF, PA and BMI did not influence the observed associations. Women who did not meet current PA recommendation or those who were low fit at baseline had a higher BMI throughout adulthood than their more active or fit peers, but the trajectory of BMI was unassociated with baseline activity or fitness levels., Conclusion: We concluded that the age-related longitudinal patterns in physical activity and fitness are not linear. Baseline activity and fitness levels are associated with BMI status during adulthood, but do not affect BMI change trajectory.

Background: Prior studies suggest that weight satisfaction may preclude changes in behavior that lead to healthier weight among individuals who are overweight or obese., Objective: To gain a better understanding of complex relationships between weight satisfaction, weight-related health behaviors, and health outcomes., Design: Cross-sectional analysis of data from the Aerobics Center Longitudinal Study (ACLS)., Participants: Large mixed-gender cohort of primarily white, middle-to-upper socioeconomic status (SES) adults with baseline examination between 1987 and 2002 (n = 19,003)., Main Outcome Variables: Weight satisfaction, weight-related health behaviors, chronic health conditions, and clinical health indicators., Statistical Analyses Performed: Chi-square test, t-tests, and linear and multivariate logistic regression., Results: Compared to men, women were more likely to be dieting (32% women; 18% men) and had higher weight dissatisfaction. Men and women with greater weight dissatisfaction reported more dieting, yo-yo dieting, and snacking and consuming fewer meals, being less active, and having to eat either more or less than desired to maintain weight regardless of weight status. Those who were overweight or obese and dissatisfied with their weight had the poorest health., Conclusion: Greater satisfaction with one's weight was associated with positive health behaviors and health outcomes in both men and women and across weight status groups.

The authors examined the independent and combined associations of physical activity and obesity with incident type 2 diabetes among 675,496 Korean men from the database of the National Health Insurance Corporation. During an average follow-up of 7.5 years (1996-2005), 52,995 men developed type 2 diabetes. Men with overweight, obese I, and obese II classifications had 1.47, 2.05, and 3.69 times higher risk of type 2 diabetes, respectively, compared with normal weight men, and men with low, medium, and high activity had 5%, 10%, and 9% lower risk of type 2 diabetes, respectively, compared with inactive men after adjustment for confounders and physical activity or body mass index for each other. Overweight and obesity were detrimental within all activity categories, and meeting the activity recommendations (medium and high activity) was beneficial at all body mass index levels. Meeting the activity recommendations appeared to attenuate some negative effects of overweight or obesity, and the increased risk of type 2 diabetes due to inactivity was lower in normal weight men. Both preventing overweight or obesity and increasing physical activity are important to reduce the global epidemic of type 2 diabetes, regardless of body weight and activity levels.

Background: The combined associations of changes in cardiorespiratory fitness and body mass index (BMI) with mortality remain controversial and uncertain., Methods and Results: We examined the independent and combined associations of changes in fitness and BMI with all-cause and cardiovascular disease (CVD) mortality in 14 345 men (mean age 44 years) with at least 2 medical examinations. Fitness, in metabolic equivalents (METs), was estimated from a maximal treadmill test. BMI was calculated using measured weight and height. Changes in fitness and BMI between the baseline and last examinations over 6.3 years were classified into loss, stable, or gain groups. During 11.4 years of follow-up after the last examination, 914 all-cause and 300 CVD deaths occurred. The hazard ratios (95% confidence intervals) of all-cause and CVD mortality were 0.70 (0.59-0.83) and 0.73 (0.54-0.98) for stable fitness, and 0.61 (0.51-0.73) and 0.58 (0.42-0.80) for fitness gain, respectively, compared with fitness loss in multivariable analyses including BMI change. Every 1-MET improvement was associated with 15% and 19% lower risk of all-cause and CVD mortality, respectively. BMI change was not associated with all-cause or CVD mortality after adjusting for possible confounders and fitness change. In the combined analyses, men who lost fitness had higher all-cause and CVD mortality risks regardless of BMI change., Conclusions: Maintaining or improving fitness is associated with a lower risk of all-cause and CVD mortality in men. Preventing age-associated fitness loss is important for longevity regardless of BMI change.

Many studies have found cross-sectional associations between characteristics of the neighborhood built environment and physical activity (PA) behavior. However, most are based on self-reported PA, which is known to result in overestimation of PA and differential misclassification by demographic and biological characteristics. Cardiorespiratory fitness (CRF) is an objective marker of PA because it is primarily determined by PA. Furthermore, it is causally related to long-term health outcomes. Therefore, analyses of the association between CRF and built environment could strengthen arguments for the importance of built environment influences on health. We examined the association between neighborhood walkability and CRF and body-mass index (BMI). This cross-sectional analysis included 16,543 adults (5017 women, 11,526 men) aged 18-90 years with home addresses in Texas who had a comprehensive clinical examination between 1987 and 2005. Outcomes included CRF from total duration on a maximal exercise treadmill test and measured BMI. Three neighborhood walkability factors emerged from principal components analyses of block-group measures derived from the U.S. Census. In multilevel adjusted analyses, the neighborhood walkability factors were significantly associated with CRF and BMI among men and women in the expected direction. An interaction between one of the neighborhood factors and age was also observed. The interaction suggested that living in neighborhoods with older homes and with residents traveling shorter distances to work was more strongly positively associated with CRF among younger adults and more strongly negatively associated with BMI among older adults. In conclusion, neighborhood characteristics hypothesized to support more PA and less driving were associated with higher levels of CRF and lower BMI. Demonstration of an association between built environment characteristics and CRF is a significant advance over past studies based on self-reported PA. Nevertheless, stronger causal evidence depends on more robust study designs and sophisticated measures of the environment, behavior, and their physiological consequences., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Background: This study examined the associations of body mass index (BMI), waist circumference (WC), and cardiorespiratory fitness (CRF) with incident functional limitation (IFL) in adults., Methods: Patients (n = 2400), 30+ years [mean age, 45.2 (SD, 8.3); 12% women], completed a baseline health examination during 1979 to 1995. CRF was quantified by age-and sex-specific thirds for maximal treadmill exercise test duration. Adiposity was assessed by BMI and WC (grouped for analysis according to clinical guidelines). Incident IFL was identified from mail-back surveys during 1995, 1999, and 2004., Results: After adjusting for potential confounders and either BMI or WC, CRF was inversely related to IFL (P trend < .001). The association between BMI and IFL was significant after adjusting for all confounders (P trend = .002), but not after additional adjustment for CRF (P trend = .23). After controlling for all confounders and CRF, high WC was associated with greater odds of IFL in those aged 30 to 49; normal WC was associated with greater odds of IFL in those aged 50+., Conclusions: CRF was a significant predictor of IFL in middle aged and older adults, independent of overall or abdominal adiposity. Clinicians should consider the importance of preserving functional capacity by recommending regular physical activity for normal-weight and overweight individuals., (©2011 Human Kinetics, Inc.)

The purpose of the study was to determine the relation between quintiles of muscular strength after adjustment for age and body weight, and excessive body fat (EBF) and excessive abdominal fat (EAF) when controlling for cardiorespiratory fitness (CRF) and other potential confounders. A two-phased cross-sectional and longitudinal study was conducted assessing the prevalence and incidence of EBF and EAF across quintiles of muscular strength. The sample included 3,258 men (mean age = 42.2 ± 8.9; weight (kg) = 81.2 ± 11.0; BMI = 25.3 ± 2.9; %fat = 19.4 ± 5.8; waist girth (cm) = 91.2 ± 9.0) who completed at least two clinical examinations as part of the Aerobics Center Longitudinal Study (ACLS). Muscular strength was assessed with tests of upper and lower body muscular strength using rack-mounted weights with participants placed into strength quintiles. CRF was measured by a modified Balke treadmill test, %fat via underwater weighing or seven-site skinfold measurements, and waist girth measured at the level of the umbilicus. EBF was defined as ≥25% and EAF was defined as >102 cm. There was a strong inverse gradient across quintiles of muscular strength for prevalence and incidence of EBF and EAF (P trend <0.01, each). With the lowest quintile serving as the referent, reductions in risk of EBF and EAF exceeded 70% for the highest strength quintile. Evidence suggests muscular strength may provide protection from EBF and EAF and their related comorbidities.

Background: Cardiorespiratory fitness (CRF) in adults decreases with age and is influenced by lifestyle. Low CRF is associated with risk of diseases and the ability of older persons to function independently. We defined the longitudinal rate of CRF decline with aging and the association of aging and lifestyle with CRF., Methods: We studied a cohort of 3429 women and 16 889 men, aged 20 to 96 years, from the Aerobics Center Longitudinal Study who completed 2 to 33 health examinations from 1974 to 2006. The lifestyle variables were body mass index, self-reported aerobic exercise, and smoking behavior. Cardiorespiratory fitness was measured by a maximal Balke treadmill exercise test., Results: Linear mixed models regression analysis stratified by sex showed that the decline in CRF with age was not linear. After 45 years of age, CRF declined at an accelerated rate. For each unit of increase in body mass index, the CRF of women declined 0.20 metabolic equivalents (METs) (95% confidence interval, -0.21 to -0.19); that of men, 0.32 METs (-0.33 to -0.20). Current smokers of both sexes also had lower CRF (-0.29 METs [95% confidence interval, -0.40 to -0.19] for women and -0.41 METS [-0.44 to -0.38] for men). Cardiorespiratory fitness was positively associated with self-reported physical activity., Conclusions: Cardiorespiratory fitness in men and women declines at a nonlinear rate that accelerates after 45 years of age. Maintaining a low BMI, being physically active, and not smoking are associated with higher CRF across the adult life span.

Substantial observational epidemiological evidence exists that physical activity and weight control are associated with decreased risk of postmenopausal breast cancer. Uncertainty remains regarding several aspects of these associations, including the effect of possible confounding factors on these associations. We present the rationale and design for two randomized controlled trials that can help resolve this uncertainty. In a 5-year prevention trial conducted among women at high risk of breast cancer, the primary endpoint would be breast cancer incidence. For a comparable survivorship trial, the primary endpoint would be the disease-free interval and secondary endpoints would be breast cancer recurrence-free interval, second primary breast cancer, and total invasive plus in situ breast cancer. A set of inclusion and exclusion criteria is proposed for both trials. Intervention goals are the same for both trials. Goals for the weight control intervention would be, for women whose body mass index (BMI) is greater than 25 kg/m(2), to lose 10% of body weight and, for women whose BMI is less than or equal to 25 kg/m(2), to avoid weight gain. The goal for the physical activity intervention would be to achieve and maintain regular participation in a moderate-intensity physical activity program for a total of 150-225 minutes over at least 5 days per week. Sample size calculations are based on alternative assumptions about hazard ratio, adherence, follow-up duration, and power and are presented for the primary prevention and survivorship trials. Although both studies could enhance our understanding of breast cancer etiology and benefit public health, practical considerations, including smaller sample size, ease of recruitment, and reduced likelihood of early termination, favor the survivorship trial at this time.

Background: Few prospective studies have evaluated the risk for incident hypertension (HTN) across the normal range of body mass index (BMI). Even fewer studies included body composition and fat distribution measurements in their analyses. In the Aerobics Center Longitudinal Study, we examined HTN risk in women across a wide spectrum of baseline BMI (kg/m(2)) values and also studied waist circumference (WC, cm), percent body fat, fat mass (FM, kg), and fat-free mass (FFM, kg) on incident HTN in subgroup analyses., Methods: A total of 5,296 healthy normotensive women between 20 and 77 years of age completed a baseline examination during 1971-2004, and were followed for HTN incidence. Incident HTN was identified using mail-back surveys., Results: A total of 592 women reported HTN during a mean 16.7 years of follow-up. Higher BMI, even within the "normal" range, was associated with greater risk of HTN. Compared with women in the lowest fifth of BMI (18.5-20.0 kg/m(2)), the hazard ratios (HRs) (95% confidence interval (CI)) of developing HTN for women with a BMI of 20.1-21.2, 21.3-22.5, 22.6-24.7, and >24.7 were 1.19 (0.89-1.60), 1.33 (0.99-1.78), 1.36 (1.03-1.81), and 2.01 (1.52-2.66), respectively (P(trend) < 0.001). In a subgroup (n = 3,189) with complete data on all the five adiposity measures, significant positive associations with HTN were seen across incremental fifths of BMI, percent body fat, and FM (P(trend) < 0.05 each), but not WC and FFM., Conclusions: Clinicians should emphasize the importance of weight management for the primary prevention of HTN in women.

Introduction: Cardiorespiratory fitness and regular physical activity are inversely associated with the risk of hypertension, and exercise training has been shown to lower elevated blood pressure (BP). Genetic factors contribute significantly to the interindividual differences in endurance training-induced changes in BP. However, similar data on the genotype-by-fitness interactions on the risk of hypertension are scarce., Methods: In 2000, we started a systematic collection of blood samples from all consenting subjects of the Aerobics Center Longitudinal Study (ACLS) with a goal to generate a resource for studies addressing genotype-by-fitness interaction effects on various health-related end points. Here, we introduce the rationale and design of the first study based on the ACLS genetics resource focusing on hypertension as the health outcome (HYPGENE study), and we report the associations of cardiorespiratory fitness and body mass index (BMI) with the risk of hypertension. All HYPGENE subjects (N = 1234) were healthy and normotensive at their first clinic visit. Cases (N = 629) developed hypertension during the follow-up period (mean 8.7 yr), whereas controls (N = 605) remained normotensive (mean follow-up 10.1 yr)., Results: Cardiorespiratory fitness was the strongest predictor of the hypertension risk, with each maximal metabolic equivalent unit being associated with a 19% lower risk (95% confidence interval [95% CI], 12-24%). Each baseline BMI unit was associated with a 9% higher hypertension risk (95% CI, 4-13%). However, the association of BMI was greatly attenuated (odds ratio 1.04 [95% CI, 0.99-1.09]) when fitness also was included in the model., Conclusions: The HYPGENE study will provide an excellent resource to address hypotheses regarding the genetic basis of hypertension while taking cardiorespiratory fitness level into account.

Objective: The purpose of this study was to examine differences in cardiovascular disease (CVD) risk factors across four cross-tabulated groups of cardiorespiratory fitness and body mass index in 8- to 18-year-old children and adolescents., Methods: The sample included 296 boys and 188 girls (mean age=15.7 years) participating in the Aerobics Center Longitudinal Study. Participants were cross tabulated into four groups using a median split of age-adjusted treadmill time to exhaustion (TM) and body mass index (BMI). Group differences in CVD risk factors (blood pressure [BP], fasting total cholesterol [TC], low density lipoprotein-cholesterol [LDL-C], high density lipoprotein-cholesterol [HDL-C], TC:HDL-C, triglycerides [TG], glucose, and a metabolic syndrome score) were examined by ANCOVA, controlling for age., Results: In males, significant differences across groups were observed for systolic BP, mean arterial pressure (MAP), TC, LDL-C, TC:HDL-C and the metabolic syndrome score (p<0.05). In females, only TG was significantly different across groups (p<0.05). A trend for significance was also observed for DBP and TG in males (p=0.09 to 0.11) and diastolic BP, MAP, HDL-C, and the metabolic syndrome score in females (p=0.14 to 0.16). In general, males and females in the low BMI group, either fit or unfit, had lower BP and blood lipid values than those in the high BMI group. In both sexes, the high BMI/low fit group had the highest (most adverse) metabolic syndrome score., Conclusion: This study utilized a unique approach to examine the possible interaction of fitness and fatness on CVD risk factors in children and adolescents. The results provide some evidence for the consideration of both variables when interpreting CVD risk factors in young people.

Background: Questions remain as to whether higher levels of cardiorespiratory fitness, a measure of regular physical activity, are associated with lower risk of cardiovascular disease (CVD) mortality in overweight and obese individuals with diabetes. Our objective was to quantify the independent and joint relations of cardiorespiratory fitness (hereafter, fitness) and body mass index (BMI; calculated as weight in kilograms divided by the square of height in meters) with CVD mortality in men with diabetes., Methods: This study was conducted using prospective observational data from the Aerobics Center Longitudinal Study. Study participants comprised 2316 men with no history of stroke or myocardial infarction and who were diagnosed as having diabetes (mean [SD] age, 50 [10] years); had a medical examination, including a maximal exercise test during 1970 to 1997 with mortality surveillance to December 31, 1998; and had a BMI of 18.5 or greater and less than 35.0. The main outcome measure was CVD mortality across levels of fitness with stratification by BMI., Results: We identified 179 CVD deaths during a mean (SD) follow-up of 15.9 (7.9) years and 36,710 man-years of exposure. In a model containing age, examination year, fasting glucose level, systolic blood pressure, parental history of premature CVD, total cholesterol level, cigarette smoking, abnormal resting, and exercise electrocardiograms, a significantly higher adjusted risk of mortality was observed in men with a low fitness level who were normal weight (hazard ratio, 2.7 [95% confidence interval, 1.3-5.7]), overweight (hazard ratio, 2.7 [95% confidence interval, 1.4-5.1]), and class 1 obese (hazard ratio, 2.8 [95% confidence interval, 1.4-5.1]) compared with normal weight men with a high fitness level., Conclusion: In this cohort of men with diabetes, low fitness level was associated with increased risk of CVD mortality within normal weight, overweight, and class 1 obese weight categories.

Purpose: To examine the relationship between cardiorespiratory fitness and body fatness during adolescence and cardiovascular disease (CVD) risk factors in adulthood., Methods: The sample was 48 participants from the Aerobics Center Longitudinal Study (ACLS) who had one clinical visit during adolescence (mean age = 15.8 years) and a follow-up visit during adulthood (mean age = 26.6 years). Values for treadmill time (TM), body fatness (body mass index [BMI], percent body fat [%BF], and waist circumference [WC]), traditional CVD risk factors (blood pressure [BP], fasting total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C], triglycerides [TG], and glucose), and a composite metabolic syndrome risk factor score were adjusted for age and sex. The relationships between adolescent TM and body fatness variables and adult CVD risk factors were examined by partial correlations, controlling for length of follow-up (mean = 11 years). The correlation between changes in TM and body fatness (DeltaTM and Deltabody fatness, respectively) and changes in CVD risk factors between adolescence and adulthood (DeltaCVD risk factors) were also examined. Adolescent cardiorespiratory fitness and body fatness variables also were separated into 2 categories based on the median split: low (below median) and high (above median)., Results: TM and body fatness variables showed moderate stability between adolescence and adulthood ( r = 0.44-0.78). Adolescent TM and DeltaTM showed moderate correlations with adult body fatness indicators (BMI, WC, and %BF, r = -0.34 to -0.47) and Deltabody fatness ( r = -0.24 to -0.46), respectively. Adolescent TM was not significantly related to traditional CVD risk factors in adulthood. Adolescent WC was significantly related to adult BP ( r = 0.33 to 0.45), and body fatness variables during adolescence were significantly related to adult TM ( r = -0.32 to -0.44). The DeltaWC was significantly related to DeltaTM ( r = -0.46) and DeltaHDL-C ( r = -0.51), and DeltaBMI was significantly related to DeltaBP ( r = 0.45) and DeltaHDL-C ( r = -0.34). Subjects with a high TM during adolescence showed lower levels of body fatness as adults, and those with high levels of WC during adolescence showed higher BP during adulthood., Conclusions: The results indicate a significant relationship between adolescent cardiorespiratory fitness and adult body fatness and a lack of an association between adolescent cardiorespiratory fitness and adult cholesterol, BP, and glucose levels. Adolescent body fatness is moderately related to selected adult CVD risk factors.

Purpose: To determine whether, for a given body mass index (BMI), men with high cardiorespiratory fitness (CRF) have lower waist circumference (WC) and less total abdominal, abdominal subcutaneous, and visceral adipose tissue (AT) compared with men with low CRF., Methods: Subjects were categorized into HIGH CRF (N = 169) and LOW CRF (N = 124) groups based on age and CRF measured using a maximal treadmill test. Total abdominal, abdominal subcutaneous and visceral AT were measured by computerized tomography., Results: For a given BMI, men in the HIGH CRF group had significantly lower WC (P < 0.001), total abdominal (P < 0.001), visceral AT (P < 0.001), and abdominal subcutaneous AT (P < 0.001) compared with men in the LOW CRF group., Conclusion: These findings suggest that the ability of CRF to attenuate the health risks associated with BMI may be partially mediated through a reduction in abdominal AT. Accordingly, our observations reinforce the importance of regular physical activity in the prevention and reduction of obesity-related health risk independent of a corresponding reduction in body weight.

Objective: To examine the relation of body mass index (BMI), cardiorespiratory fitness (CRF), and all-cause mortality in women., Research Methods and Procedures: A cohort of women (42.9 +/- 10.4 years) was assessed for CRF, height, and weight. Participants were divided into three BMI categories (normal, overweight, and obese) and three CRF categories (low, moderate, and high). After adjustment for age, smoking, and baseline health status, the relative risk (RR) of all-cause mortality was determined for each group. Further multivariate analyses were performed to examine the contribution of each predictor (e.g., age, BMI, CRF, smoking status, and baseline health status) on all-cause mortality while controlling for all other predictors., Results: During follow-up (113,145 woman-years), 195 deaths from all causes occurred. Compared with normal weight (RR = 1.0), overweight (RR = 0.92) and obesity (RR = 1.58) did not significantly increase all-cause mortality risk. Compared with low CRF (RR = 1.0), moderate (RR = 0.48) and high (RR = 0.57) CRF were associated significantly with lower mortality risk (p = 0.002). In multivariate analyses, moderate (RR = 0.49) and high (RR = 0.57) CRF were strongly associated with decreased mortality relative to low CRF (p = 0.003). Compared with normal weight (RR = 1.0), overweight (RR = 0.84) and obesity (RR = 1.21) were not significantly associated with all-cause mortality., Discussion: Low CRF in women was an important predictor of all-cause mortality. BMI, as a predictor of all-cause mortality risk in women, may be misleading unless CRF is also considered.

Swimming, water jogging, and aqua aerobics are lifetime physical activities that provide many health benefits comparable to those of walking and running. Research on the association between swimming and mortality is scarce, however. To evaluate the association between different types of physical activity and all cause mortality, we studied 40,547 men age 20-90 years who completed a health examination during 1971-2003. Cox proportional-hazards regression was used to estimate the relative risks according to physical activity exposure categories. A total of 3,386 deaths occurred during 543,330 man-years of observation. After adjustment for age, body-mass index, smoking status, alcohol intake, and family history of cardiovascular disease, swimmers had 53%, 50%, and 49% lower all-cause mortality risk than did men who were sedentary, walkers, or runners, respectively (p < .05 for each). Additional adjustment for baseline prevalent diseases did not change the inverse association between different activities and all-cause mortality. In conclusion, swimmers had lower mortality rates than those who were sedentary, walkers, and runners. [ABSTRACT FROM AUTHOR]

Sleep disturbances, chronotype and social jetlag (SJL) have been associated with increased risks for major chronic diseases that take decades to develop, such as obesity, metabolic syndrome and cardiovascular disease. Potential relationships between poor sleep, chronotype and SJL as they relate to metabolic risk factors for chronic disease have not been extensively investigated. This prospective study examined chronotype, SJL and poor sleep in relation to both obesity and elevated blood pressure among healthy young adults. SJL and objective sleep measures (total sleep time, sleep onset latency, wake after sleep onset and sleep efficiency) were derived from personal rest/activity monitoring (armband actigraphy) among 390 healthy adults 21-35 years old. Participants wore the device for 6-10 days at 6-month intervals over a 2-year period (n = 1431 repeated observations). Chronotypes were categorized into morning, intermediate and evening groups using repeated measures latent class analysis. Means of SJL and sleep measures among latent chronotype groups were compared using partial F-tests in generalized linear mixed models. Generalized linear mixed models also were used to generate odds ratios (ORs) with 95% confidence intervals (CIs) examining the relationship between repeated measures of chronotype, SJL, sleep and concurrent anthropometric outcome measures (body mass index, percentage of body fat, waist-to-hip ratio, waist-to-height ratio), systolic blood pressure and diastolic blood pressure. Sleep latency ≥12 min was associated with increased odds of a high waist-to-height ratio (OR = 1.37; CI: 1.03-1.84). Neither chronotype nor SJL was independently associated with anthropometric outcomes or with blood pressure. Relationships between poor sleep and anthropometric outcomes or blood pressure varied by chronotype. Morning types with total sleep time <6 h, sleep efficiency <85% or wake after sleep onset ≥60 min were more likely to have an increased percentage of body fat, waist-to-hip ratio and waist-to-height ratio relative to those with an intermediate chronotype. Similarly, sleep latency ≥12 min was associated with increased odds of elevated systolic blood pressure (OR = 1.90; CI: 1.15-3.16, pinteraction = 0.02) among morning versus intermediate chronotypes. No relationships between poor sleep and obesity or elevated blood pressure were observed among evening chronotypes. The results from this study among healthy young adults suggest that poor sleep among morning types may be more strongly associated with obesity and elevated blood pressure relative to those with an intermediate (neutral) chronotype. Sleep-related metabolic alterations among different chronotypes warrant further investigation. [ABSTRACT FROM AUTHOR]

The article focuses on obesity being a rising danger for public health which can later lead to weight-related health problems. It talks about mortality risk being connected to a high level of body mass index (BMI) and the need to improve cardiometabolic health that are caused through obesity. It tells about the importance of fitness in obese people.

Background: Assessments of energy intake (EI) are frequently affected by measurement error. Recently, a simple equation was developed and validated to estimate EI on the basis of the energy balance equation [EI = changed body energy stores + energy expenditure (EE)].Objective: The purpose of this study was to compare multiple estimates of EI, including 2 calculated from the energy balance equation by using doubly labeled water (DLW) or activity monitors, in free-living adults.Methods: The body composition of participants (n = 195; mean age: 27.9 y; 46% women) was measured at the beginning and end of a 2-wk assessment period with the use of dual-energy X-ray absorptiometry. Resting metabolic rate (RMR) was calculated through indirect calorimetry. EE was assessed with the use of the DLW technique and an arm-based activity monitor [Sensewear Mini Armband (SWA); BodyMedia, Inc.]. Self-reported EI was calculated by using dietitian-administered 24-h dietary recalls. Two estimates of EI were calculated with the use of a validated equation: quantity of energy stores estimated from the changes in fat mass and fat-free mass occurring over the assessment period plus EE from either DLW or the SWA. To compare estimates of EI, reporting bias (estimated EI/EE from DLW × 100) and Goldberg ratios (estimated EI/RMR) were calculated.Results: Mean ± SD EEs from DLW and SWA were 2731 ± 494 and 2729 ± 559 kcal/d, respectively. Self-reported EI was 2113 ± 638 kcal/d, EI derived from DLW was 2723 ± 469 kcal/d, and EI derived from the SWA was 2720 ± 730 kcal/d. Reporting biases for self-reported EI, DLW-derived EI, and SWA-derived EI are as follows: -21.5% ± 22.2%, -0.7% ± 18.5%, and 0.2% ± 20.8%, respectively. Goldberg cutoffs for self-reported EI, DLW EI, and SWA EI are as follows: 1.39 ± 0.39, 1.77 ± 0.38, and 1.77 ± 0.38 kcal/d, respectively.Conclusions: These results indicate that estimates of EI based on the energy balance equation can provide reasonable estimates of group mean EI in young adults. The findings suggest that, when EE derived from DLW is not feasible, an activity monitor that provides a valid estimate of EE can be substituted for EE from DLW. [ABSTRACT FROM AUTHOR]

Objectives: We examined the independent and combined associations of cardiorespiratory fitness (CRF), body fat (BF) percentage (BF%), and body mass index (BMI) with submaximal systolic blood pressure (SSBP) among young adult women. Materials and Methods: Analyses included a sample of 211 normotensive women with a BMI between 20 and 35 kg/m2; BF% was calculated using total BF measured from dual X-ray absorptiometry, CRF was assessed using a graded exercise test, and SSBP was measured at each stage. Results: There was a significant direct association of SSBP with BF% and BMI, whereas an inverse association between SSBP and CRF when adjusted for the covariates. There was no significant association between SSBP and BF% across the stages 1-3 with a borderline significant association at stage 4 when further adjusted for CRF, whereas no association at any of the stages when adjusted for BMI. A borderline significant association between SSBP and BMI was found at stage 1 and significant association at stages 2-4 when additionally adjusted for CRF, whereas the association disappeared at stages 1-2 when adjusted for BF%. The inverse association between SSBP and CRF was eliminated at stages 3-4 when further adjusted for BF% with borderline significant association at stages 1-2. The associations remained significant at the stages 1-2 but not at stages 3-4 after adjusting for BMI. Conclusion: CRF, BF%, and BMI seem to have critical roles in determining SSBP with CRF and BF% being more potent at lower intensity exercise, whereas BMI was more strongly associated at higher intensity exercise. [ABSTRACT FROM AUTHOR]