Associations of cardiorespiratory fitness and body mass index with incident restrictive spirometry pattern.

OBJECTIVES: Restrictive spirometry pattern (RSP) suggests an impairment of lung function associated with a significantly increased risk of premature mortality. We evaluated the independent and joint associations of cardiorespiratory fitness (CRF) and body mass index with incident RSP. METHODS: Data from the Aerobics Centre Longitudinal Study included 12 360 participants (18-82 years). CRF was assessed by maximal treadmill test and categorised into five groups. Body mass index was categorised into normal weight (<25.0 kg/m2), overweight (25.0-29.9 kg/m2) or obesity (≥30.0 kg/m2). RSP was defined as the simultaneous occurrence of forced expiratory volume in 1 s/force vital capacity ≥lower limit of normal and forced vital capacity

Objectively Measured Physical Activity and Sedentary Time Among Adults With and Without Stroke: A National Cohort Study.

Background and Purpose: We examined differences in the volume and pattern of physical activity (PA) and sedentary behavior between adults with and without stroke. Methods: We studied cohort members with an adjudicated or self-reported stroke (n=401) and age-, sex-, race-, region of residence-, and body mass index-matched participants without a history of stroke (n=1203) from the REGARDS study (Reasons for Geographic and Racial Differences in Stroke). Sedentary behavior (total volume and bouts), light-intensity PA, and moderate-to-vigorous-intensity PA were objectively measured for 7 days via hip-worn accelerometer. Results: Sedentary time (790.5±80.4 versus 752.4±81.9 min/d) and mean sedentary bout duration (15.7±12.6 versus 11.9±8.1 min/d) were higher and PA (light-intensity PA: 160.5±74.6 versus 192.9±73.5 min/d and moderate-to-vigorous-intensity PA: 9.0±11.9 versus 14.7±17.0 min/d) lower for stroke survivors compared with controls (P<0.001). Stroke survivors also accrued fewer activity breaks (65.5±21.9 versus 73.31±18.9 breaks/d) that were shorter (2.4±0.7 versus 2.7±0.8 minutes) and lower in intensity (188.4±60.8 versus 217.9±72.2 counts per minute) than controls (P<0.001). Conclusions: Stroke survivors accrued a lower volume of PA, higher volume of sedentary time, and exhibited accrual patterns of more prolonged sedentary bouts and shorter, lower intensity activity breaks compared with persons without stroke.

Resistance exercise, alone and in combination with aerobic exercise, and obesity in Dallas, Texas, US: A prospective cohort study.

BACKGROUND: Obesity is a significant and growing public health problem in high-income countries. Little is known about the relationship between resistance exercise (RE), alone and in combination with aerobic exercise (AE), and the risk of developing obesity. The purpose of this prospective cohort study was to examine the associations between different amounts and frequencies of RE, independent of AE, and incident obesity. METHODS AND FINDINGS: Participants were 11,938 healthy adults ages 18-89 years with a BMI < 30 kg/m2 at baseline who completed at least 2 clinical examinations during 1987-2005 as part of the Aerobics Center Longitudinal Study. Self-reported RE participation in minutes/week and days/week was collected from a standardized questionnaire. Incident obesity was defined as a BMI ≥ 30 kg/m2 at follow-up. Incident obesity was also defined by waist circumference (WC) > 102/88 cm for men/women and percent body fat (PBF) ≥ 25%/30% for men/women at follow-up in participants who were not obese by WC (n = 9,490) or PBF (n = 8,733) at baseline. During the average 6-year follow-up, 874 (7%), 726 (8%), and 1,683 (19%) developed obesity defined by BMI, WC, or PBF, respectively. Compared with no RE, 60-119 min/wk of RE was associated with 30%, 41%, and 31% reduced risk of obesity defined by BMI (hazard ratio [95% CI], 0.70 [0.54-0.92], p = 0.008), WC (0.59 [0.44-0.81], p < 0.001), and PBF (0.69 [0.57-0.83], p < 0.001), respectively, after adjusting for confounders including age, sex, examination year, smoking status, heavy alcohol consumption, hypertension, hypercholesterolemia, diabetes, and AE. Compared with not meeting the RE guidelines of ≥2 d/wk, meeting the RE guidelines was associated with 18%, 30%, and 30% reduced risk of obesity defined by BMI (hazard ratio [95% CI], 0.82 [0.69-0.97], p = 0.02), WC (0.70 [0.57-0.85], p < 0.001), and PBF (0.70 [0.62-0.79], p < 0.001), respectively. Compared with meeting neither guideline, meeting both the AE and RE guidelines was associated with the smallest hazard ratios for obesity. Limitations of this study include limited generalizability as participants were predominantly white men from middle to upper socioeconomic strata, use of self-reported RE, and lack of detailed diet data for the majority of participants. CONCLUSIONS: In this study, we observed that RE was associated with a significantly reduced risk of obesity even after considering AE. However, meeting both the RE and AE guidelines was associated with the lowest risk of obesity.

Sedentary Behavior, Exercise, and Cardiovascular Health.

Sedentary behavior and physical inactivity are among the leading modifiable risk factors worldwide for cardiovascular disease and all-cause mortality. The promotion of physical activity and exercise training (ET) leading to improved levels of cardiorespiratory fitness is needed in all age groups, race, and ethnicities and both sexes to prevent many chronic diseases, especially cardiovascular disease. In this state-of-the-art review, we discuss the negative impact of sedentary behavior and physical inactivity, as well as the beneficial effects of physical activity /ET and cardiorespiratory fitness for the prevention of chronic noncommunicable diseases, including cardiovascular disease. We review the prognostic utility of cardiorespiratory fitness compared with obesity and the metabolic syndrome, as well as the increase of physical activity /ET for patients with heart failure as a therapeutic strategy, and ET dosing. Greater efforts at preventing sedentary behavior and physical inactivity while promoting physical activity, ET, and cardiorespiratory fitness are needed throughout the healthcare system worldwide and particularly in the United States in which the burden of cardiometabolic diseases remains extremely high.

The association of fitness and fatness with intermediate hyperglycemia incidence in women: A cohort study.

The purpose of this study was to examine the associations of cardiorespiratory fitness, general adiposity, and central adiposity with incident intermediate hyperglycemia (IH) in women. We conducted a prospective cohort study of 1534 women aged 20-79 years old who had an annual health check-up with no history of major chronic diseases. At baseline, fitness was assessed by a Balke graded exercise test, and the estimated metabolic equivalents were used to create quartile groups. Women were also grouped based on their body mass index (<25 kg/m2, 25-29.9 kg/m2, and ≥ 30 kg/m2) and waist-to-height ratio (≥0.50 or < 0.50). Cox proportional hazards models were conducted to assess the association of fitness and fatness variables with incident IH defined as fasting glucose of 5.6-6.9 mmol/L. Overall, 18.1% (n = 277) of the women developed IH during an average follow-up of 5.06 years. Fitness, body mass index, and waist-to-height ratio at baseline were the independent predictors of the IH incidence in separate age-adjusted models; yet when all three variables were included in the same model along with confounding variables, only fitness remained significant and demonstrated a clear inverse association with incident IH (P-for-trend <0.001). Health promotion efforts should focus on improving fitness for the prevention of IH in women.

Objectively measured physical activity and all cause mortality: A systematic review and meta-analysis.

Current physical activity recommendations have been based on evidence from systematic reviews of questionnaire-based data. Questionnaire-based physical activity data are subject to both random and non-random error. If the estimated association between physical activity and health outcomes was different when a more accurate, objective measure was used, this would have important health policy implications for physical activity. We conducted a systematic review and meta-analysis of published cohort studies that investigated the association between an objective measure of physical activity and all cause mortality. We searched PubMed, Scopus, Embase, Cochrane library, and SPORTDiscus for prospective cohort studies that examined the association between objectively measured (accelerometer, pedometer, or doubly labeled water method) physical activity and mortality in adults aged≥18 years, of either sex. Summary hazard ratios and 95% confidence interval [CI]s were computed using random-effects models. Thirty-three articles from 15 cohort studies were identified that together ascertained 3903 deaths. The mean years of follow-up ranged from 2.3-14.2 years. Individuals in the highest category of light, moderate-to-vigorous, and total physical activity had 40% (95%CI 20% to 55%), 56% (95%CI 41% to 67%), and 67% (95%CI 57% to 75%), respectively, lower risk for mortality compared to individuals in the lowest category of light, moderate-to-vigorous, and total physical activity. The summary hazard ratio for objectively measured physical activity and all cause mortality is lower than previously estimated from questionnaire based studies. Current recommendations for physical activity that are based on subjective measurement may underestimate the true reduction in mortality risk associated with physical activity.

Body flexibility and incident hypertension: The Niigata wellness study.

A high level of physical fitness, especially cardiorespiratory fitness, is associated with lower incidence of hypertension. However, the relationship between flexibility, which is a component of physical fitness, and the incidence of hypertension is unknown. The purpose of this study was to investigate the relationship between flexibility and the incidence of hypertension in a cohort study. A total of 22,972 (14,805 men and 8167 women; median age 49 years) normotensive participants were included in this study. Between April 2001 and March 2002, flexibility (standing forward bending) was measured using a standing trunk flexion meter. The participants were divided into quartiles of flexibility by sex and age group. Hypertension was defined as systolic blood pressure ≥ 140 mm Hg, diastolic blood pressure ≥ 90 mm Hg, or a self-reported history of previously diagnosed hypertension or current medication for hypertension at a health examination between April 2002 and March 2008. Hazard ratios and 95% confidence intervals (95% CI) for the incidence of hypertension were estimated using Cox proportional hazards models after adjusting for age, sex, body mass index, exercise habits, smoking status, and drinking status. During 102,948 person years of follow-up (median 5.6 years), 4235 participants developed hypertension. Compared with the lowest flexibility (quartile 1), hazard ratios and 95% CI were 0.96 (0.88 - 1.04) for quartile 2, 0.94 (0.86 - 1.03) for quartile 3, and 0.83 (0.76 - 0.91) for quartile 4. A high level of flexibility was associated with lower incidence of hypertension, independent of other confounding factors.

Is adiposity associated with objectively measured physical activity and sedentary behaviors in older adults?

BACKGROUND: Many older adults in the U.S. do not achieve the recommended amount of physical activity (PA) to fully realize a myriad of health benefits. Adiposity is one of those important correlates of PA and sedentary behaviors. However, the full extent to which adiposity is associated with PA and stationary time (STA) is uncertain. Therefore, we examined the association of adiposity with objectively measured PA and STA in black and white older adults. METHODS: We conducted a cross-sectional study of older adults enrolled in the REasons for Geographic and Racial Differences in Stroke (REGARDS) Study 2003-2007 who participated in an ancillary accelerometer study 2009-2013. Assessment of body mass index (BMI) and waist circumference (WC) was completed during an in-home visit in the parent study. PA was measured by Actical™ accelerometers, which provided estimates of moderate-to-vigorous-intensity PA (MVPA), light-intensity PA (LPA), and STA for 4-7 consecutive days. Data from accelerometers were standardized to square root percentages of total wear time per day (SqrtMVPA%, SqrtLPA%, and SqrtSTA%). Interactions were tested for BMI and WC by race and sex, separately. RESULTS: Data were available for 7873 participants (69.8 ± 8.7 yr, 54.2% women, 31.5% African American). In mixed linear regression models, significant interactions existed in BMI by race and sex for the SqrtMVPA%, WC by race and sex for the SqrtMVPA% and the SqrtLPA% model(p < 0.05). No interaction was significant for the logistic model of meeting the PA guideline or not. In subgroup analyses, BMI was inversely associated with SqrtMVPA%, SqrtLPA%, and positively related to SqrtSTA% in black women, white men and white women after adjustments. Similar patterns were observed between WC and SqrtMVPA%, SqrtLPA%, and SqrtSTA% in all groups, respectively. However, BMI was not associated with SqrtMVPA% in black men. Those with higher BMI or WC were less likely to meet the PA guideline in all groups. CONCLUSIONS: Adiposity was inversely associated with higher levels of MVPA/LPA and positively associated with higher levels of STA among black and white older adults. Prevention efforts aimed at promoting weight control may be beneficial to prevent physical inactivity and sedentary lifestyle among older adults.

Comparison of the Cardiovascular Benefits of Resistance, Aerobic, and Combined Exercise (CardioRACE): Rationale, design, and methods.

BACKGROUND: The benefits of aerobic exercise (AE) for cardiovascular disease (CVD) have been well documented. Resistance exercise (RE) has been traditionally examined for its effects on bone density, physical function, or metabolic health, yet few data exist regarding the benefits of RE, independent of and combined with AE, for CVD prevention. This randomized controlled trial, "Comparison of the Cardiovascular Benefits of Resistance, Aerobic, and Combined Exercise (CardioRACE)," is designed to determine the relative benefits of RE, AE, or combined RE plus AE training on CVD risk factors. METHODS: Participants are 406 inactive men and women (35-70 years) with a body mass index of 25-40 kg/m2 and blood pressure (BP) of 120-139/80-89 mm Hg without taking antihypertensive medications. Participants are randomly assigned to RE only, AE only, combined RE and AE (CE), or a no exercise control group. Participants perform supervised exercise at 50%-80% of their relative maximum intensity for both AE and RE, 3 times a week for 60 minutes per session, for 1 year (all 3 groups are time matched). RESULTS: The primary outcome is a composite z score including resting BP, low-density lipoprotein cholesterol (LDL-C), fasting glucose, and percent body fat, which is assessed at baseline, 6 months, and 12 months. Diet and outside physical activity are measured throughout the intervention for 1 year. CONCLUSION: CardioRACE (ClinicalTrials.govNCT03069092) will fill an important knowledge gap regarding the effects of RE, alone or in addition to the well-documented effects of AE. CardioRACE will help generate more comprehensive and synergistic clinical and public health strategies to prevent CVD.

Sedentary behaviour is associated with diabetes mellitus in adults: findings of a cross-sectional analysis from the Brazilian National Health System.

BACKGROUND: Sedentary behaviour (SB) may contribute to the development of several chronic diseases, such as hypertension, diabetes mellitus (DM) and all-cause mortality. The aim of this study is to investigate the association between different domains of SB with diabetes among adult users of the Brazilian National Health System (NHS). METHODS: Cross-sectional study from the primary care system of the Brazilian NHS in the city of Bauru, Brazil. SB, physical activity (PA), DM and other chronic diseases were assessed by face-to-face interviews and medical records. As potential confounders in the adjusted model, we used gender, age, economic status, smoking status, hypertension, hypercholesterolaemia and PA. RESULTS: The study was composed of 147 men and 410 women. The fully adjusted model showed that Brazilian adults spending ≥3 h per day in television viewing (OR = 1.61 [95% CI: 1.11-2.33]) and overall SB (OR = 1.60 [95% CI: 1.09-2.36]) had increased prevalence of DM compared to those spending <3 h per day. CONCLUSIONS: TV viewing and overall SB was associated with higher prevalence of DM in Brazilian adults from the NHS, even after controlling for potential confounders including PA.

Association of TV Viewing and All-Cause Mortality in Older Adults With Hypertension: A 6-Year Longitudinal Study.

The purpose of this study was to examine the longitudinal association between television (TV) viewing and all-cause mortality in older adults with hypertension. Sedentary behavior, physical activity, hypertension, and other chronic diseases were assessed by face-to-face interviews and confirmed by medical history. Mortality was reported by relatives and confirmed in medical records of the National Health System. The fully adjusted model showed a direct association between high TV viewing time and all-cause mortality; hazard ratio: 1.65 (95% confidence interval [1.02-2.68]). Women with high TV viewing were more likely to die than men. Higher TV viewing time was associated with all-cause mortality among those with diabetes and hypertension; hazard ratio: 3.54 (95% confidence interval [1.64-7.66]). The findings from this longitudinal study show that higher TV viewing time is associated with higher risk for all-cause mortality among older adults with hypertension, independently of physical activity, and other potential confounders.

Energy Intake Derived from an Energy Balance Equation, Validated Activity Monitors, and Dual X-Ray Absorptiometry Can Provide Acceptable Caloric Intake Data among Young Adults.

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.

Obesity and Cardiovascular Disease.

The prevalence of obesity has increased worldwide over the past few decades. In 2013, the prevalence of obesity exceeded the 50% of the adult population in some countries from Oceania, North Africa, and Middle East. Lower but still alarmingly high prevalence was observed in North America (≈30%) and in Western Europe (≈20%). These figures are of serious concern because of the strong link between obesity and disease. In the present review, we summarize the current evidence on the relationship of obesity with cardiovascular disease (CVD), discussing how both the degree and the duration of obesity affect CVD. Although in the general population, obesity and, especially, severe obesity are consistently and strongly related with higher risk of CVD incidence and mortality, the one-size-fits-all approach should not be used with obesity. There are relevant factors largely affecting the CVD prognosis of obese individuals. In this context, we thoroughly discuss important concepts such as the fat-but-fit paradigm, the metabolically healthy but obese (MHO) phenotype and the obesity paradox in patients with CVD. About the MHO phenotype and its CVD prognosis, available data have provided mixed findings, what could be partially because of the adjustment or not for key confounders such as cardiorespiratory fitness, and to the lack of consensus on the MHO definition. In the present review, we propose a scientifically based harmonized definition of MHO, which will hopefully contribute to more comparable data in the future and a better understanding on the MHO subgroup and its CVD prognosis.

Importance of Achieving a "Fit" Cardiorespiratory Fitness Level for Several Years on the Incidence of Type 2 Diabetes Mellitus: A Japanese Cohort Study.

BACKGROUND: The "Physical Activity Reference for Health Promotion 2013" provides "fit" reference values for cardiorespiratory fitness (CRF) for good health. The importance of achieving a fit CRF level for several years on the subsequent prevention of type 2 diabetes mellitus (T2DM) remains to be clarified. METHODS: This cohort study was conducted in 2,235 nondiabetic males aged 21 to 59 years, enrolled in April 1986 through March 1987. We calculated the ratio of the area under the curve (AUCratio) for actual measured values and the AUC for the reference values of CRF in each individual during an 8-year measurement period before the baseline. According to whether they met a fit CRF level or not, participants were categorized into groups based on the AUCratio (FitAUC or UnfitAUC) and initial CRF (Fitinitial or Unfitinitial), respectively. T2DM was evaluated on health checkups until March 2010. RESULTS: During the follow-up period, 400 men developed T2DM. After adjustment for confounders, as compared with those in the FitAUC group, the hazard ratio (HR) for those in the UnfitAUC group was 1.33 (95% confidence interval [CI], 1.06-1.65). A combined analysis with the categories of initial value and AUCratio showed that, compared with the Fitinitial and FitAUC group, the HRs of Fitinitial and UnfitAUC, Unfitinitial and FitAUC, and Unfitinitial and UnfitAUC groups were 1.41 (95% CI, 0.99-2.00), 1.18 (95% CI, 0.81-1.70), and 1.40 (95% CI, 1.08-1.83), respectively. CONCLUSION: Achievement of a fit CRF level established in the Japan physical activity guideline for several years was associated with lower subsequent risk of T2DM.

Long-term Impact of Cardiorespiratory Fitness on Type 2 Diabetes Incidence: A Cohort Study of Japanese Men.

BACKGROUND: We sought to examine the association between cardiorespiratory fitness (CRF) and incidence of type 2 diabetes considering the follow-up period in a cohort of Japanese men with a maximum follow-up period of 23 years. METHODS: This study enrolled 7,804 male workers free of diabetes in 1986. CRF was measured using a cycle ergometer, and maximal oxygen uptake was estimated. During 1986-2009, participants were followed for development of type 2 diabetes, which was diagnosed using fasting blood tests, self-administered questionnaires, or oral glucose tolerance tests after urinary tests from annual health checkups. Hazard ratios for the incidence of type 2 diabetes were estimated using Cox proportional hazards models. RESULTS: During the follow-up period, 1,047 men developed type 2 diabetes. In analyses by follow-up periods (1986-1993, 1994-2001, and 2002-2009), there was an inverse dose-response relationship between CRF and the development of type 2 diabetes for all three follow-up periods (P for trend 0.019, <0.001, and 0.001, respectively), and the association between CRF at baseline and the incidence of type 2 diabetes did not weaken with longer follow-up period. Compared with the lowest CRF group, hazard ratios of developing type 2 diabetes were 0.69 (95% confidence interval [CI], 0.49-0.97) for the highest CRF group in 1986-1993, 0.57 (95% CI, 0.42-0.79) for the highest CRF in 1994-2001, and 0.47 (95% CI, 0.30-0.74) for the highest CRF in 2002-2009. CONCLUSION: High CRF is associated with a lower risk of the incidence of type 2 diabetes over an extended period of >20 years among men.

Daily step count and all-cause mortality in a sample of Japanese elderly people: a cohort study.

BACKGROUND: This study aimed to examine the relationship between pedometer-assessed daily step count and all-cause mortality in a sample of elderly Japanese people. METHODS: Participants included 419 (228 males and 191 females) physically independent, community-dwelling 71-year-old Japanese people. The number of steps per day was measured by a waist-mounted pedometer for seven consecutive days at baseline. Participants were divided into quartiles based on their average number of steps/day (first quartile, < 4503 steps/day; second quartile, 4503-6110 steps/day; third quartile, 6111-7971 steps/day; fourth quartile, > 7972 steps/day) and were followed up over a mean period of 9.8 years (1999-2010) for mortality. RESULTS: Seventy-six participants (18.1%) died during the follow-up period. The hazard ratios (adjusted for sex, body mass index, cigarette smoking, alcohol intake, and medication use) for mortality across the quartiles of daily step count (lowest to highest) were 1.00 (reference), 0.81 (95%CI, 0.43-1.54), 1.26 (95%CI, 0.70-2.26), and 0.46 (95%CI, 0.22-0.96) (P for trend = 0.149). Participants in the highest quartile had a significantly lower risk of death compared with participants in the lowest quartile. CONCLUSION: This study suggested that a high daily step count is associated with a lower risk of all-cause mortality in physically independent Japanese elderly people.

Patterns of Sedentary Behavior and Mortality in U.S. Middle-Aged and Older Adults: A National Cohort Study.

BACKGROUND: Excessive sedentary time is ubiquitous in Western societies. Previous studies have relied on self-reporting to evaluate the total volume of sedentary time as a prognostic risk factor for mortality and have not examined whether the manner in which sedentary time is accrued (in short or long bouts) carries prognostic relevance. OBJECTIVE: To examine the association between objectively measured sedentary behavior (its total volume and accrual in prolonged, uninterrupted bouts) and all-cause mortality. DESIGN: Prospective cohort study. SETTING: Contiguous United States. PARTICIPANTS: 7985 black and white adults aged 45 years or older. MEASUREMENTS: Sedentary time was measured using a hip-mounted accelerometer. Prolonged, uninterrupted sedentariness was expressed as mean sedentary bout length. Hazard ratios (HRs) were calculated comparing quartiles 2 through 4 to quartile 1 for each exposure (quartile cut points: 689.7, 746.5, and 799.4 min/d for total sedentary time; 7.7, 9.6, and 12.4 min/bout for sedentary bout duration) in models that included moderate to vigorous physical activity. RESULTS: Over a median follow-up of 4.0 years, 340 participants died. In multivariable-adjusted models, greater total sedentary time (HR, 1.22 [95% CI, 0.74 to 2.02]; HR, 1.61 [CI, 0.99 to 2.63]; and HR, 2.63 [CI, 1.60 to 4.30]; P for trend < 0.001) and longer sedentary bout duration (HR, 1.03 [CI, 0.67 to 1.60]; HR, 1.22 [CI, 0.80 to 1.85]; and HR, 1.96 [CI, 1.31 to 2.93]; P for trend < 0.001) were both associated with a higher risk for all-cause mortality. Evaluation of their joint association showed that participants classified as high for both sedentary characteristics (high sedentary time [≥12.5 h/d] and high bout duration [≥10 min/bout]) had the greatest risk for death. LIMITATION: Participants may not be representative of the general U.S. population. CONCLUSION: Both the total volume of sedentary time and its accrual in prolonged, uninterrupted bouts are associated with all-cause mortality, suggesting that physical activity guidelines should target reducing and interrupting sedentary time to reduce risk for death. PRIMARY FUNDING SOURCE: National Institutes of Health.

Importance of Assessing Cardiorespiratory Fitness in Clinical Practice: A Case for Fitness as a Clinical Vital Sign: A Scientific Statement From the American Heart Association.

Mounting evidence has firmly established that low levels of cardiorespiratory fitness (CRF) are associated with a high risk of cardiovascular disease, all-cause mortality, and mortality rates attributable to various cancers. A growing body of epidemiological and clinical evidence demonstrates not only that CRF is a potentially stronger predictor of mortality than established risk factors such as smoking, hypertension, high cholesterol, and type 2 diabetes mellitus, but that the addition of CRF to traditional risk factors significantly improves the reclassification of risk for adverse outcomes. The purpose of this statement is to review current knowledge related to the association between CRF and health outcomes, increase awareness of the added value of CRF to improve risk prediction, and suggest future directions in research. Although the statement is not intended to be a comprehensive review, critical references that address important advances in the field are highlighted. The underlying premise of this statement is that the addition of CRF for risk classification presents health professionals with unique opportunities to improve patient management and to encourage lifestyle-based strategies designed to reduce cardiovascular risk. These opportunities must be realized to optimize the prevention and treatment of cardiovascular disease and hence meet the American Heart Association's 2020 goals.

Exercise and the cardiovascular system: clinical science and cardiovascular outcomes.

Substantial evidence has established the value of high levels of physical activity, exercise training (ET), and overall cardiorespiratory fitness in the prevention and treatment of cardiovascular diseases. This article reviews some basics of exercise physiology and the acute and chronic responses of ET, as well as the effect of physical activity and cardiorespiratory fitness on cardiovascular diseases. This review also surveys data from epidemiological and ET studies in the primary and secondary prevention of cardiovascular diseases, particularly coronary heart disease and heart failure. These data strongly support the routine prescription of ET to all patients and referrals for patients with cardiovascular diseases, especially coronary heart disease and heart failure, to specific cardiac rehabilitation and ET programs.

Is There a Dose-Response Relationship between Tea Consumption and All-Cause, CVD, and Cancer Mortality?

BACKGROUND: A small change in tea consumption at population level could have large impact on public health. However, the health benefits of tea intake among Americans are inconclusive. OBJECTIVE: To evaluate the association between tea consumption and all-causes, cardiovascular disease (CVD) and cancer mortality in the Aerobics Center Longitudinal study (ACLS). METHODS: 11808 participants (20-82 years) initially free of CVD and cancers enrolled in the ACLS and were followed for mortality. Participants provided baseline self-report of tea consumption (cups/day). During a median follow-up of 16 years, 842 participants died. Of others, 250 died from CVD, and 345 died from cancer, respectively. A Cox proportional hazard model was used to produce hazard ratio (HR) and 95% confidence interval (CI). RESULTS: Compared with participants consuming no tea, tea drinkers had a survival advantage ( Log-2 = 10.2, df = 3, P = 0.017); however, the multivariate hazard ratios (HRs) of all-cause mortality for those drinking 1-7, 8-14, and >14 cups/week were 0.95 (95% CI, 0.81-1.12), 1.00 (95% CI, 0.82-1.22), and 0.98 (95% CI, 0.76-1.25), respectively (P for linear trend = 0.83). The multivariate HR were 1.16 (95% CI, 0.86-1.56), 1.22 (95% CI, 0.85-1.76), and 0.94 (95% CI, 0.56-1.54) for CVD mortality (P for linear trend = 0.47), and 0.97 (95% CI, 0.75-1.25), 0.85 (95% CI, 0.60-1.16), and 0.94 (95% CI, 0.64-1.38) for cancer mortality (P for trend = 0.62). CONCLUSIONS: There were week or null relationships between tea consumption and mortality due to all-cause, CVD disease or cancer were observed in ACLS.