I-Min Lee

Physical Activity and Public Health Updated Recommendation for Adults From the American College of Sports Medicine and the American Heart Association

SUMMARY In 1995 the American College of Sports Medicine and the Centers for Disease Control and Prevention published national guidelines on Physical Activity and Public Health. The Committee on Exercise and Cardiac Rehabilitation of the American Heart Association endorsed and supported these recommendations. The purpose of the present report is to update and clarify the 1995 recommendations on the types and amounts of physical activity needed by healthy adults to improve and maintain health. Development of this document was by an expert panel of scientists, including physicians, epidemiologists, exercise scientists, and public health specialists. This panel reviewed advances in pertinent physiologic, epidemiologic, and clinical scientific data, including primary research articles and reviews published since the original recommendation was issued in 1995. Issues considered by the panel included new scientific evidence relating physical activity to health, physical activity recommendations by various organizations in the interim, and communications issues. Key points related to updating the physical activity recommendation were outlined and writing groups were formed. A draft manuscript was prepared and circulated for review to the expert panel as well as to outside experts. Comments were integrated into the final recommendation. PRIMARY RECOMMENDATION To promote and maintain health, all healthy adults aged 18 to 65 yr need moderate-intensity aerobic (endurance) physical activity for a minimum of 30 min on five days each week or vigorous-intensity aerobic physical activity for a minimum of 20 min on three days each week. [I (A)] Combinations of moderate- and vigorous-intensity activity can be performed to meet this recommendation. [IIa (B)] For example, a person can meet the recommendation by walking briskly for 30 min twice during the week and then jogging for 20 min on two other days. Moderate-intensity aerobic activity, which is generally equivalent to a brisk walk and noticeably accelerates the heart rate, can be accumulated toward the 30-min minimum by performing bouts each lasting 10 or more minutes. [I (B)] Vigorous-intensity activity is exemplified by jogging, and causes rapid breathing and a substantial increase in heart rate. In addition, every adult should perform activities that maintain or increase muscular strength and endurance a minimum of two days each week. [IIa (A)] Because of the dose-response relation between physical activity and health, persons who wish to further improve their personal fitness, reduce their risk for chronic diseases and disabilities or prevent unhealthy weight gain may benefit by exceeding the minimum recommended amounts of physical activity. [I (A)]

Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory, Musculoskeletal, and Neuromotor Fitness in Apparently Healthy Adults: Guidance for Prescribing Exercise

SUMMARYThe purpose of this Position Stand is to provide guidance to professionals who counsel and prescribe individualized exercise to apparently healthy adults of all ages. These recommendations also may apply to adults with certain chronic diseases or disabilities, when appropriately evaluated and

Physical activity and public health: updated recommendation for adults from the American College of Sports Medicine and the American Heart Association.

On Line Network is a listserv that creates an international network of physical activity and public health practitioners, researchers, and interested others. To subscribe to this listserv, send an email to listserv@listserv.sc.edu. In the body of the email type: SUBSCRIBE PHYS-ACT, along with your first and last name or anonymous, if you wish to have your subscription hidden. from the Centers for Disease Control and Prevention. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention. The University of South Carolina does not discriminate in educational or employment opportunities or decisions for qualified persons on the basis of race Promoting Health Through Physical Activity partners and stakeholders in center activities, and increase participation in cancer prevention and control behaviors among high-risk and disparate populations. Physical Activity Resources We maintain an extensive website (http:// prevention.sph.sc.edu/index.htm) to provide resources and information to researchers, public health practitioners, and others who are interested in promoting physical activity in their communities. The USC Prevention Research Center Notes is a quarterly e-mail newsletter with current information about physical activity and public health. To subscribe to the newsletter, send an email to listserv@listserv.sc.edu. In the body of the email type: SUBSCRIBE PRCNEWS, along with your first and last name or anonymous, if you wish to have your subscription hidden. Please visit the USC PRC website to explore our physical activity tools, many developed by the PRC, often in partnership with local communities.SUMMARY In 1995 the American College of Sports Medicine and the Centers for Disease Control and Prevention published national guidelines on Physical Activity and Public Health. The Committee on Exercise and Cardiac Rehabilitation of the American Heart Association endorsed and supported these recommendations. The purpose of the present report is to update and clarify the 1995 recommendations on the types and amounts of physical activity needed by healthy adults to improve and maintain health. Development of this document was by an expert panel of scientists, including physicians, epidemiologists, exercise scientists, and public health specialists. This panel reviewed advances in pertinent physiologic, epidemiologic, and clinical scientific data, including primary research articles and reviews published since the original recommendation was issued in 1995. Issues considered by the panel included new scientific evidence relating physical activity to health, physical activity recommendations by various organizations in the interim, and communications issues. Key points related to updating the physical activity recommendation were outlined and writing groups were formed. A draft manuscript was prepared and circulated for review to the expert panel as well as to outside experts. Comments were integrated into the final recommendation. PRIMARY RECOMMENDATION To promote and maintain health, all healthy adults aged 18 to 65 yr need moderate-intensity aerobic (endurance) physical activity for a minimum of 30 min on five days each week or vigorous-intensity aerobic physical activity for a minimum of 20 min on three days each week. [I (A)] Combinations of moderate- and vigorous-intensity activity can be performed to meet this recommendation. [IIa (B)] For example, a person can meet the recommendation by walking briskly for 30 min twice during the week and then jogging for 20 min on two other days. Moderate-intensity aerobic activity, which is generally equivalent to a brisk walk and noticeably accelerates the heart rate, can be accumulated toward the 30-min minimum by performing bouts each lasting 10 or more minutes. [I (B)] Vigorous-intensity activity is exemplified by jogging, and causes rapid breathing and a substantial increase in heart rate. In addition, every adult should perform activities that maintain or increase muscular strength and endurance a minimum of two days each week. [IIa (A)] Because of the dose-response relation between physical activity and health, persons who wish to further improve their personal fitness, reduce their risk for chronic diseases and disabilities or prevent unhealthy weight gain may benefit by exceeding the minimum recommended amounts of physical activity. [I (A)].

The Association of Changes in Physical-Activity Level and Other Lifestyle Characteristics with Mortality among Men

BACKGROUND Recent trends toward increasing physical exercise, stopping cigarette smoking, and avoiding obesity may increase longevity. We analyzed changes in the lifestyles of Harvard College alumni and the associations of these changes with mortality. METHODS Men who were 45 to 84 years of age in 1977 and who had reported no life-threatening disease on questionnaires completed in 1962 or 1966 and again in 1977 were classified according to changes in lifestyle characteristics between the first and second questionnaires. We analyzed changes in their level of physical activity, cigarette smoking, blood pressure, and body weight, and the relation of these factors to mortality between 1977 and 1985. RESULTS Of the 10,269 men, 476 died during this period (which totaled 90,650 man-years of observation). Beginning moderately vigorous sports activity (at an intensity of 4.5 or more metabolic equivalents) was associated with a 23 percent lower risk of death (95 percent confidence interval, 4 to 42 percent; P = 0.015) than not taking up moderately vigorous sports. Quitting cigarette smoking was associated with a 41 percent lower risk (95 percent confidence interval, 20 to 57 percent; P = 0.001) than continuing smoking, but with a 23 percent higher risk than constant nonsmoking. Men with recently diagnosed hypertension had a lower risk of death than those with long-term hypertension (relative risk, 0.75; 95 percent confidence interval, 0.55 to 1.02; P = 0.057), as did men with consistently normal blood pressure (relative risk, 0.52; 95 percent confidence interval, 0.40 to 0.68; P < 0.001). Maintenance of lean body mass was associated with a lower mortality rate than long-term, recent, or previous obesity. The associations between changes in lifestyle and mortality were independent and were largely undiminished by age. Our findings on death from coronary heart disease mirrored those on death from all causes. CONCLUSIONS Beginning moderately vigorous sports activity, quitting cigarette smoking, maintaining normal blood pressure, and avoiding obesity were separately associated with lower rates of death from all causes and from coronary heart disease among middle-aged and older men.

Physical Activity and Reduced Risk of Cardiovascular Events Potential Mediating Mechanisms

Background— Higher levels of physical activity are associated with fewer cardiovascular disease (CVD) events. Although the precise mechanisms underlying this inverse association are unclear, differences in several cardiovascular risk factors may mediate this effect. Methods and Results— In a prospective study of 27 055 apparently healthy women, we measured baseline levels of hemoglobin A1c, traditional lipids (total, low-density lipoprotein, and high-density lipoprotein cholesterol), novel lipids [lipoprotein(a) and apolipoprotein A1 and B-100], creatinine, homocysteine, and inflammatory/hemostatic biomarkers (high-sensitivity C-reactive protein, fibrinogen, soluble intracellular adhesion molecule-1) and used womens self-reported physical activity, weight, height, hypertension, and diabetes. Mean follow-up was 10.9±1.6 years, and 979 incident CVD events occurred. The risk of CVD decreased linearly with higher levels of activity (P for linear trend <0.001). Using the reference group of <200 kcal/wk of activity yielded age- and treatment-adjusted relative risk reductions associated with 200 to 599, 600 to 1499, and ≥1500 kcal/wk of 27%, 32%, and 41%, respectively. Differences in known risk factors explained a large proportion (59.0%) of the observed inverse association. When sets of risk factors were examined, inflammatory/hemostatic biomarkers made the largest contribution to lower risk (32.6%), followed by blood pressure (27.1%). Novel lipids contributed less to CVD risk reduction compared with traditional lipids (15.5% and 19.1%, respectively). Smaller contributions were attributed to body mass index (10.1%) and hemoglobin A1c/diabetes (8.9%), whereas homocysteine and creatinine had negligible effects (<1%). Conclusions— The inverse association between physical activity and CVD risk is mediated in substantial part by known risk factors, particularly inflammatory/hemostatic factors and blood pressure.

Long-Term Weight Loss and Changes in Blood Pressure: Results of the Trials of Hypertension Prevention, Phase II

Approximately one fourth of the U.S. adult populationnearly 50 million peoplehas hypertension (1, 2). Taking a broader perspective, more than half of the adult population has higher than optimal blood pressure (1), defined as systolic blood pressure greater than 120 mm Hg and diastolic blood pressure greater than 80 mm Hg (2). These persons are at significantly increased risk for cardiovascular disease and stroke (3). Although pharmacologic treatment for hypertension significantly reduces morbidity and mortality from cardiovascular diseases (4, 5), long-term pharmacologic therapy can have undesirable side effects and requires the expense of continuing medical supervision. Furthermore, pharmacologic therapy is not usually initiated when blood pressure is higher than optimal yet below diagnostic thresholds for hypertension. Thus, lifestyle interventions for primary prevention and initial treatment of high blood pressure remain a vital strategy for controlling this highly prevalent condition (2). Weight loss has been shown to reduce blood pressure in overweight hypertensive patients (6-9) and in overweight persons with high-normal blood pressure (10-12). Two reviews of randomized trials of weight reduction to reduce blood pressure examined the results of nine studies (13, 14). Most of these trials were small, only one had more than 500 participants (11), and most had short-term follow-up (1 year or less). Only three studies had follow-up of 3 to 5 years (8, 10, 11). Compared with controls, weight loss averaged nearly 7 kg in the short-term trials and approximately 3 kg in the three longer-term trials. In almost all trials, systolic blood pressure and diastolic blood pressure were reduced in the intervention groups. Since these reviews were published, the Trials of Hypertension Prevention (TOHP) Phase I reported mean weight reduction of 3.9 kg at 18 months in 564 overweight participants with high-normal blood pressure, resulting in significant decreases in systolic blood pressure and diastolic blood pressure compared with a usual care control group (12, 15). To investigate whether nonpharmacologic interventions can prevent hypertension over the long term, TOHP II was initiated. This was a randomized, controlled trial examining the effects of weight loss and dietary sodium reduction, alone and in combination, in reducing blood pressure in overweight adults with high-normal diastolic blood pressure (16). This target population is at high risk for hypertension as they age. The primary outcome paper from this trial (17) provided only a brief overview of the effects of weight loss on blood pressure. Here, we provide more detailed analysis of weight loss and blood pressure in TOHP II. Of special interest are the long-term effects of weight loss on blood pressure, the magnitude of the doseresponse relationship at 36 months, the effect of patterns of weight loss on blood pressure, and the predictors of weight loss and blood pressure response. Methods Participants Participants in TOHP II were overweight adults with nonmedicated diastolic blood pressure of 83 to 89 mm Hg and systolic blood pressure less than 140 mm Hg. Other eligibility criteria included age 30 to 54 years and a body mass index of 26.1 to 37.4 kg/m2 for men and 24.4 to 37.4 kg/m2 for women, approximately 110% to 165% of ideal weight (18). Principal exclusion criteria were current treatment with medications that might affect blood pressure, clinical or laboratory evidence of cardiovascular disease, diabetes mellitus, renal insufficiency (serum creatinine concentration 150 mol/L [ 1.7 mg/dL] for men and 132 mol/L [ 1.5 mg/dL] for women), and current or planned pregnancy. Detailed descriptions of recruitment and participant characteristics have been published elsewhere (19, 20). The study was reviewed and approved by the institutional review boards at all nine TOHP centers and the coordinating center, and all participants signed informed consent forms. Design Eligible participants were randomly assigned with equal probability to one of four groups: weight loss only, sodium reduction only, combined weight loss and sodium reduction, or usual care (controls). Measurements Age, sex, ethnicity, and years of education were obtained by questionnaire. Baseline blood pressure measurements were taken at three screening visits, each separated by 7 to 45 days. At each visit, three readings of systolic blood pressure and diastolic blood pressure were obtained and averaged. Certified staff obtained measurements in seated participants by using a Hawksley random-zero sphygmomanometer (21). Body weight was measured to the nearest 0.2 kg (0.5 lb) by using a calibrated balance-beam scale; participants wore indoor clothing (without shoes). Blood pressure and weight were measured every 6 months after randomization to the end of follow-up at 36, 42, or 48 months, depending on randomization date. Clinic staff who were blinded to study group assignment made these assessments. Blood pressure measurements were obtained during a single visit at all follow-up points except for 18 and 36 months, when measurements were taken at a series of three visits approximately 1 week apart. Multiple measurements were taken at 18 and 36 months to provide a more precise assessment of average blood pressures at these primary outcome points. Dietary intake was assessed by 24-hour recall, and physical activity was assessed by questionnaire. Intervention Participants assigned to the weight loss intervention group sought to lose at least 4.5 kg (10 lb) during the first 6 months of the intervention and to maintain their weight loss for the remainder of the trial. A brief description of the intervention methods is presented here; a more detailed description has been published elsewhere (22). The intervention started with an individual counseling session, followed by 14 weekly group meetings led by dietitians or health educators. After this 14-week intensive phase, participants attended six biweekly group meetings and then monthly group meetings. Beginning in the 18th month, participants were offered a variety of options to keep them involved in the intervention, including individual counseling sessions and special group sessions focused on selected weight loss topics. The intervention focused on self-directed behavior change (behavioral self-management), nutrition education, information on physical activity, and social support for making and maintaining behavior changes. Specific behavior change techniques included self-monitoring (food diaries and graphs of minutes of physical activity per day), setting explicit short-term goals and developing specific action plans to achieve those objectives, and developing alternative strategies for situations that trigger problem eating. The dietary intervention focused on reducing caloric intake by decreasing consumption of excess fat, sugar, and alcohol. Keeping daily food diaries was emphasized for monitoring intake and assessing progress. With experience, the participants determined the caloric intake that produced moderate weight loss for them. It was suggested that men not consume less than 1500 kcal/d and women not less than 1200 kcal/d. Weight loss of more than 0.9 kg (2 lb) per week was discouraged. The physical activity goal was to gradually increase activity to 30 to 45 minutes per day, four to five days per week. Exercise intensity was moderate, approximately 40% to 55% of heart rate reserve, and consisted primarily of brisk walking. Statistical Analysis Baseline characteristics of the weight loss and usual care groups were compared overall and by sex by using t-tests for means and chi-square tests for proportions. Although weight and blood pressure data were collected every 6 months, special efforts were made to achieve high follow-up rates at 18 and 36 months; at each of these two time points, nine blood pressure readings were collected over three visits and were averaged. For participants prescribed antihypertensive medication, follow-up blood pressure for all subsequent visits was taken to be the last study blood pressure before therapy was started. Participants receiving medications that affect blood pressure for reasons other than hypertension or who became pregnant were treated as missing at that visit. We used two-sample t-tests to compare changes in weight and blood pressure from baseline in the weight loss intervention and usual care groups overall, by sex, by ethnicity, and by sex and ethnicity. The effects of the intervention in terms of changes in weight and blood pressure were examined overall and in subgroups defined by sex, ethnicity, and sex and ethnicity. Subgroup differences were tested by using terms for the interaction of treatment group with sex and with ethnicity in multiple linear regression models. Regression analyses were also used to analyze the doseresponse relationship between change in weight and change in blood pressure, overall and within sex and ethnicity subgroups. Differences in dose response were tested by using interaction terms in linear regression models. All regressions were adjusted for age and baseline weight. We also adjusted for baseline blood pressure in the blood pressure regression models. Change in blood pressure was also examined in relation to quintile of weight loss. Quintiles were computed by using the distribution of weight change in the weight loss intervention group. Additional multiple regression analyses were performed in which weight loss participants were categorized according to patterns of weight loss at 6 and 36 months. The PROC MIXED function of SAS software (SAS Institute, Inc., Cary, North Carolina) was used to perform repeated-measures analyses that tested differences over time by pattern of weight loss. Cox proportional-hazards models were used for survival analyses, with onset of hypertension as the outcome. Results Baseline Findings The baseline characteristics of participants assigned to th

Physical Activity and Coronary Heart Disease in Men The Harvard Alumni Health Study

BackgroundThe quantity and intensity of physical activity required for the primary prevention of coronary heart disease (CHD) remain unclear. Therefore, we examined the association of the quantity and intensity of physical activity with CHD risk and the impact of other coronary risk factors. Methods and ResultsWe followed 12 516 middle-aged and older men (mean age 57.7 years, range 39 to 88 years) from 1977 through 1993. Physical activity was assessed at baseline in kilojoules per week (4.2 kJ=1 kcal) from blocks walked, flights climbed, and participation in sports or recreational activities. During follow-up, 2135 cases of incident CHD, including myocardial infarction, angina pectoris, revascularization, and coronary death, occurred. Compared with men expending <2100 kJ/wk, men expending 2100 to 4199, 4200 to 8399, 8400 to 12 599, and ≥12 600 kJ/wk had multivariate relative risks of 0.90, 0.81, 0.80, and 0.81, respectively (P for trend=0.003). When we considered the independent effects of specific physical activity components, only total sports or recreational activities (P for trend=0.042) and vigorous activities (P for trend=0.02) were inversely associated with the risk of CHD. These associations did not differ within subgroups of men defined by coronary risk factors. Finally, among men with multiple coronary risk factors, those expending ≥4200 kJ/wk had reduced CHD risk compared with men expending <4200 kJ/wk. ConclusionsTotal physical activity and vigorous activities showed the strongest reductions in CHD risk. Moderate and light activities, which may be less precisely measured, showed nonsignificant inverse associations. The association between physical activity and a reduced risk of CHD also extends to men with multiple coronary risk factors.

Physical activity and all-cause mortality: what is the dose-response relation?

PURPOSE The purpose of this review is to assess the dose-response relation between physical activity and all-cause mortality. We examined these parameters of physical activity dose: volume, intensity, duration, and frequency. METHODS We used a computer-assisted literature search to identify papers on this topic. After excluding papers examining only two levels of physical activity or fitness, papers investigating specific causes of mortality, reviews, and those not written in English, 44 papers satisfying all criteria were included in this review. RESULTS There is clear evidence of an inverse linear dose-response relation between volume of physical activity and all-cause mortality rates in men and women, and in younger and older (> or = 60 yr) persons. Minimal adherence to current physical activity guidelines, which yield an energy expenditure of about 1000 kcal x wk(-1) (4200 kJ x wk(-1)), is associated with a significant 20--30% reduction in risk of all-cause mortality. Further reductions in risk are observed at higher volumes of energy expenditure. It is unclear whether a volume of <1000 kcal x wk(-1) also may be associated with lower risk; there are some data supporting this. Due to limited data, it is also unclear whether vigorous-intensity activity confers additional benefit beyond its contribution to volume of physical activity when compared with moderate-intensity activity. No data are available on duration and frequency of physical activity in relation to all-cause mortality rates after controlling for volume of physical activity. CONCLUSIONS All studies in this review are observational studies, so conclusions are based on Evidence Category C. There is an inverse linear dose-response relation between volume of physical activity and all-cause mortality. Further research is needed to clarify the contributions of its components--intensity, duration, and frequency--to decreased all-cause mortality rates.

A multistage genome-wide association study in breast cancer identifies two new risk alleles at 1p11.2 and 14q24.1 (RAD51L1).

We conducted a three-stage genome-wide association study (GWAS) of breast cancer in 9,770 cases and 10,799 controls in the Cancer Genetic Markers of Susceptibility (CGEMS) initiative. In stage 1, we genotyped 528,173 SNPs in 1,145 cases of invasive breast cancer and 1,142 controls. In stage 2, we analyzed 24,909 top SNPs in 4,547 cases and 4,434 controls. In stage 3, we investigated 21 loci in 4,078 cases and 5,223 controls. Two new loci achieved genome-wide significance. A pericentromeric SNP on chromosome 1p11.2 (rs11249433; P = 6.74 × 10−10 adjusted genotype test, 2 degrees of freedom) resides in a large linkage disequilibrium block neighboring NOTCH2 and FCGR1B; this signal was stronger for estrogen-receptor–positive tumors. A second SNP on chromosome 14q24.1 (rs999737; P = 1.74 × 10−7) localizes to RAD51L1, a gene in the homologous recombination DNA repair pathway. We also confirmed associations with loci on chromosomes 2q35, 5p12, 5q11.2, 8q24, 10q26 and 16q12.1.

Practice Guideline2013 AHA/ACC Guideline on Lifestyle Management to Reduce Cardiovascular Risk: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines☆

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