Physical Activity Guidelines for Health and Prosperity in the United States

Family History of Chronic Disease and Meeting Public Health Guidelines for Physical Activity: The Cooper Center Longitudinal Study

Armed Conflict in Central America and Immigrant Health in the United States.

Most older adults are living with at least one chronic health condition that can be positively modified through regular exercise, but less than 15% of this population achieve national physical activity guidelines for health. Several social, organizational, and environmental barriers contribute to the physical activity participation gap. Physical inactivity is highest among older adults with chronic disease and disability, reporting non-white race or Hispanic ethnicity, and lower socioeconomic and educational levels. Inaccessible recreational environments also limit community-based exercise and physical activity by older adults. While it is a federal mandate for all public buildings to comply with Americans with Disabilities Act (ADA) accessibility standards, there are additional recreational considerations for older adults that are rarely addressed or corrected. The purpose of this project is to evaluate the recreational accessibility of the Drexel Recreation Center, a public health club in the heart of an urban university campus that is proximate to some of the most socioeconomically disadvantaged older adult residents in the United States as defined by the Area Deprivation Index. Using the Person-Environment-Occupation-Performance (PEOP) model, the team completed a recreational needs assessment inclusive of the Accessibility Instruments Measuring Fitness and Recreation Environments (AIMFREE) tool, physical therapy and occupational therapy clinical knowledge, and community advisory board member input. A voluntary electronic survey was sent to older adults who are current or prospective members of the recreation center to determine use, barriers, and facilitators to participation. Data collection is ongoing, with a planned townhall to distribute results to all invested community members.

Toward the Healthy City by Jason Coburn offers an interesting journey through the history of planning and public health in the United States, by examining the common ground of health and social justice, as well as the forces and circumstances responsible for the disconnect between the fields during the 20th century. The book provides concrete evidence for the need to reconnect the fields to address the systemic failure and health crises in today’s cities. The author suggests a new decision-making framework and explores how public health and planning agencies along with community-based coalitions in the San Francisco Bay Area are currently redefining environmental health policies to improve the health of both people and places. The book herewith moves beyond much contemporary research that tends to document problems in cities, and in particular in poor neighborhoods and communities, without examining the political and administrative changes in municipal government and governance. Chapter 1 is introductory and explains the challenges for “healthy city planning.” The starting point is the understanding of urban places and city planning processes as critical determinants of population health. The author explains that recent efforts to reconnect the fields of public health and urban planning in the United States have focused on a very limited conception of healthy planning, and suggests a new and more comprehensive decision-making framework: “healthy city planning.” Chapter 2 critically reviews the practices of US city planning and public health from the late 19th century to the start of the 21st century. Chapter 3 then considers how city planning processes fail to address the social determinants of health and contribute to the perpetuation of health inequity in cities. Chapter 4 specifically considers alternative issue framings that include considerations of population health, a relational view of place, processes of governance, and relations of power. The author applies this conceptual framework in the analysis of three case studies (2004–2008) of healthy city planning in San Francisco and across the Bay Area: the reframing of environmental health practice, healthy urban development, and using health impact assessment for urban and regional planning. These cases, described in chapters 5–7, clearly illustrate how planning can return to its health and

Peace in Guatemala and Immigrant Health in the United States.

Background: Physical activity behavior is influenced by a complex set of interrelated variables.Objective: To describe the literature of objectively measured (accelerometer and pedometer) physical activity involving individuals with intellectual disability using the International Classification of Functioning, Disability and Health (ICF) model of Functioning and Disability as a framework.Major findings: Overall, studies were small in scale; included individuals with higher intellectual functioning; and tended to exclude individuals with co-morbid, associated, or secondary conditions. Study results indicate that less than one-third of adults are meeting health guidelines for physical activity; however, children and youth may be more active. Whether the population is less active than the general community is uncertain; but there appears to be syndrome-specific differences in participation. The breadth of factors investigated as potential correlates of physical activity is not as wide-ranging as the general population. Factors positively associated with physical activity were social connectedness and weekday; and among children and youth, physical activity was higher among boys and younger age groups.Conclusions: The inclusion and exclusion criterion applied to studies to date suggests that estimates of physical activity are upwardly biased. Accordingly, research that represents the diversity of individuals with intellectual disability is needed. It is obvious from this review that there is a great scope to examine a broad range of factors that may influence participation in physical activity. Research would benefit from incorporating disability-specific or generic models of health or physical activity participation to help select, organize, and interpret factors of importance.

Mothers and teenage daughters walking to health: using the behaviour change wheel to develop an intervention to improve adolescent girls' physical activity

Background: This cross-sectional study aimed to examine associations between motor competence, physical activity, and obesity in British children aged three to five years. Method: Motor competence (MC) was assessed using the Test of Gross Motor Development-2. Physical activity (PA) was assessed using triaxial wrist-worn accelerometers. Children were assessed on compliance to current PA recommendations of ≥180 min of total PA (TPA) and ≥60 min of moderate-to-vigorous PA (MVPA) for health benefits. Associations were explored with Pearson’s product moments and weight-status, and sex-differences were explored with independent t-tests and chi-squared analysis. Results: A total of 166 children (55% males; 4.28 ± 0.74 years) completed MC and PA assessments. Associations were found between PA and MC (TPA and overall MC, TPA and object-control MC (OC), MVPA and overall MC, and MVPA and OC). This study suggests that good motor competence is an important correlate of children meeting physical activity guidelines for health.

Physical activity guidelines for health recommend any type of unstructured physical activity for health promotion. Adults should perform at least 150-300 min per week of moderate intensity or 75-150 min per week of vigorous intensity activities, or an equivalent combination of the two intensities. However, the relationship between physical activity intensity and longevity remains a debated topic, with conflicting perspectives offered by epidemiologists, clinical exercise physiologists or anthropologists. This paper addresses the current known role of physical activity intensity (in particular vigorous versus moderate intensity) on mortality and the existing problems of measurement. Given the diversity of existing proposals to categorize physical activity intensity, we call for a common methodology. Device-based physical activity measurements (e.g., wrist accelerometers) have been proposed as a valid method to measure physical activity intensity. An appraisal of the results reported in the literature, however, highlights that wrist accelerometers have not yet demonstrated sufficient criterion validity when they are compared to indirect calorimetry. Novel biosensors and wrist accelerometers will help us understand how different metrics of physical activity relates to human health, however, all these technologies are not enough mature to provide personalized applications for healthcare or sports performance.

CURRENT STATUS OF PHYSICAL ACTIVITY AND PUBLIC HEALTH GUIDELINESIn November 2018, the U.S. Department of Health and Human Services (DHHS) issued the second edition of Physical Activity Guidelines for Americans (1). These guidelines are considered to be the "official" guidelines for physical activity and public health in the United States. The guidelines are official in that all messaging and programs dealing with physical activity and health published or supported by the U.S. Federal Government should use, or at least be consistent with, these guidelines. The first edition of the guidelines was issued in 2008 by DHHS and provided recommendations for youth, adults, and older adults (2). The guidelines were developed from research published over the past 70 years, along with previous guidelines or recommendations issued by professional organizations and government agencies in the United States over the last half-century. A Physical Activity Guidelines for Americans Midcourse Report that focuses on interventions to increase physical activity in youth was published in 2012 (3). The scientific basis for the 2008 DHHS guidelines was prepared by a Physical Activity Guidelines Advisory Committee (PAGAC) composed of experts in the sciences of physical activity and health who conducted an extensive literature review (4). In 2018, a new PAGAC accepted most of the recommendations, but not all, made by the 2008 PAGAC and the DHHS guidelines writing committee. The 2018 report noted important benefits of physical activity that are supported by strong scientific evidence (see Box 1). These new indications are in addition to the many benefits included in the 2008 DHHS guidelines, such as cardiovascular and metabolic-related health benefits, increased bone and muscle health, and significant lowering of all-cause, cardiovascular, and cancer mortality. Core recommendations in the 2018 guidelines, including to sit less and move more, a weekly target of 150 minutes per week of moderate-intensity or 75 minutes per week of vigorous-intensity aerobic activity, and frequent muscle strengthening activities, remained much the same. The major change in the activity recommendation in 2018 was to no longer require bouts of aerobic activity be of at least 10 minutes in duration—activity bouts of any duration now contribute toward the weekly goal. Although there still is limited published research testing for health benefits of exercise accumulated throughout the day in bouts lasting less than 5 minutes each, data are beginning to emerge that show the potential efficacy (see Figure 1) (5,6). However, understanding the specific health benefits of very short bouts remains in need of more research.Figure 1: Association of hazard ratio for all-cause mortality with daily activity amount in quartiles when accumulated in 10-minute bouts or total moderate- to vigorous-intensity physical activity (not using bouts).The major change in the activity recommendation in 2018 was to no longer require bouts of aerobic activity be of at least 10 minutes in duration — activity bouts of any duration now contribute toward the weekly goal. Although there still is limited published research testing for health benefits of exercise accumulated throughout the day in bouts lasting less than 5 minutes each, data are beginning to emerge that show the potential efficacy (see Figure 1) (5,6). To include a specific recommendation in the DHHS guidelines, the combined evidence from studies needs to be considered strong. For this reason, some currently popular activities, such as high-intensity interval training, were not included in the primary recommendations because of the lack of sufficient data. Also, the increased health risks caused by too much sitting were addressed with general recommendations to decrease sitting time using almost any type of activity. However, data were inadequate to support specific targets for daily sitting time. Regardless, sitting less is associated with better health, especially in low-fit and high-risk persons.Box 1 The 2018 Physical Activity Guidelines report noted important benefits of physical activity that included strong scientific evidence for reduced risk of dementia; improved cognitive function; reduced cancer of the bladder, endometrium, esophagus, kidney, lung, and stomach; health benefits for children ages 3 to 5 years; and reduced risk for adults developing a new chronic condition or risk of progression of a condition they already have (secondary prevention).BRIEF HISTORY OF THE EVOLUTION OF PHYSICAL ACTIVITY AND HEALTH GUIDELINES In 1953, the first studies were published that hypothesized moderate/vigorous-intensity physical activity performed on multiple days of the week provided some protection against coronary heart disease clinical events (7). Morris and colleagues reported that more active conductors on double-deck buses in London who walked up and down stairs during much of each shift had lower rates of coronary heart disease events compared with drivers of the same buses. Also, they reported that London postmen who walked routes carrying their mail bags had significantly fewer coronary heart disease events compared with switchboard operators who sat at work all day. Over the next two decades, other investigators who had access to data collected on large employee populations generally reported similar outcomes. Also, several early studies that included brief physical activity questionnaires found that more active men had lower rates of heart disease than their less active counterparts during longitudinal follow-up (8). During this time, several exercise physiology laboratories began reporting the results of exercise training studies on health-related biological markers such as plasma cholesterol and triglycerides, blood glucose, blood pressure (BP), adiposity, and cardiorespiratory fitness. The results of these and an increasing number of similar studies became the early scientific basis for physical activity and health recommendations or guidelines starting in the early 1970s by the American Heart Association (AHA) and the American College of Sports Medicine (ACSM). Between 1972 and 1996, ACSM, AHA, various units within the DHHS, and other organizations published a large number of recommendation or guideline documents for exercise/health professionals or the general public. A list of these recommendations between 1965 and 1996 is available in Physical Activity and Health, A Report to the Surgeon General (9). Most of the data supporting physical activity recommendations have been derived from two study designs: (a) prospective observational studies with all-cause and cause-specific mortality being the most common outcome and (b) exercise intervention (training) studies where changes in disease biomarkers are key outcomes. It is the combination of different types of results from the observational and interventional studies that lend strength to many of the current physical activity guidelines. Increases in activity produce improvement of some biomarkers in the causal pathways of various chronic diseases supporting the concept of "causality," whereas observational studies provide clinical outcomes such as mortality generally not obtainable in intervention studies because of the need for a large sample size, a long-term follow-up, and a large number of outcomes. The earliest guidelines had a major focus on exercise programs to improve cardiovascular and muscular fitness and help decrease the risk of exercise-induced cardiovascular or musculoskeletal injury in adults. For example, in the first AHA recommendations published in 1972 (10), the following precautionary statement was made: "Exercise is a therapeutic agent designed to promote a beneficial clinical effect and, as such, has specific indications and contraindications and possible toxic or adverse reactions" (page 24). Public health guidelines since the 1990s have focused more or the extensive health and performance benefits provided by being appropriately active than on the risks associated with recommended exercise. Especially important were the guidelines by the CDC and ACSM published in 1995 because of their strong public health orientation (11). Also, the ">10-minute bout requirement" was introduced in these guidelines. The ACSM guidelines provided in their position stands experienced relatively minor changes in the 33 years between 1978 and 2011. In 1978, the key recommendations focused on endurance activity of 15 to 60 minutes per session, 3 to 5 sessions per week of moderate/vigorous intensity (60% to 90% of HRmax reserve or 50% to 80% •VO2max). Activities that help maintain muscle and bone strength, flexibility, and balance were recommended (12). In 2011, key recommendations from ACSM stated that most adults should engage in moderate-intensity cardiorespiratory exercise training for ≥30 minutes per day on ≥5 days per week for a total of ≥150 minutes per week or vigorous-intensity cardiorespiratory exercise training for ≥20 minutes per day on ≥3 days per week (≥75 minutes per week), or a combination of moderate- and vigorous-intensity exercise to achieve a total EE of ≥500–1000 MET-minutes per week. On 2 to 3 days per week, adults were advised to perform resistance exercises for each of the major muscle groups, neuromotor exercise involving balance and agility, and various flexibility and coordination activities (12).Sidebar 1: METS METS are used as an indicator of energy expenditure. One MET is the rate of energy expended by a person sitting quietly, and it is considered to be 3.5 ml of oxygen per kilogram of body weight. Four METS means a person is exercising at an intensity that requires four times the energy they expend while sitting at rest. If a person exercises for 30 minutes at 4 METS, they have expended 120 MET-minutes (30 × 4) or 2 MET-hours. If this exercise is performed for 5 days, the total weekly expenditure will be 10 MET-hours or 600 MET-minutes.The 1990 ACSM Position Stand noted that in the 1978 Position Stand, an important distinction was made between physical activity as it relates to health versus fitness. It indicated that the quantity and quality of exercise needed by physically inactive individuals to attain some health-related benefits may differ from activities recommended for fitness benefits. It is now clear that lower levels of physical activity than those recommended by the ACSM Position Stands may reduce the risk of certain chronic degenerative diseases in low-fit and inactive persons and yet may not be of sufficient quantity or quality (primarily intensity) to significantly improve •VO2max. Data from large prospective observational studies or meta-analysis of such studies have shown that lower mortality rates are associated with small differences in reported moderate- and vigorous-intensity activity, especially in the least active participants — the least active benefit the most from an increase in activity (Figure 2).Figure 2: Leisure-time physical activity (MET-hours per week) and hazard ratio for all-cause mortality.FUTURE DIRECTIONS As physical activity and health research moves forward, it needs to focus on a number of unanswered questions that will inform the development of new guidelines, including the effect of light-intensity exercise on health risks or benefits, the best pattern of activity over the 24-hour day (how best to balance time spent during sleep, sedentary behavior, and activities of different types, intensities, durations, and frequency), and the efficacy and safety of short-duration HIIT in those with various chronic conditions. This research should greatly benefit from the continued development and innovative application of wearable measurement devices and related software.

Commentary The enormous burden of ill health caused by overweight and obesity is well understood, particularly in developed countries like the United States, which have seen massive increases in prevalence over the last few decades [1]. Most recently the Global Burden of Diseases, Injuries, and Risk Factors Study 2010 reported that high body mass index (BMI) is now the third-leading cause of ill health in the United States, responsible for more than one-third of ischemic heart disease, half of osteoarthritis, and three-quarters of diabetes [2]. The consequences for the health, economics, and well-being of individuals and the community are enormous [3]. At its most basic level, obesity is easily understood as a problem of energy balance–if energy intake from food exceeds energy expenditure from physical activity, weight gain ensues. Likewise, it follows that if energy intake can be reduced or physical activity increased, weight loss should follow. Less clear has been the importance of each to the causation of the obesity epidemic and the potential for interventions targeting diet versus physical activity to reverse it. The paper by Dwyer-Lindgren et al. in Population Health Metrics [4] provides important new insight into where the United States should focus its efforts over the next few years. The key observation in the report by Dwyer-Lindgren is the apparently paradoxical association between changes in physical activity and obesity–average levels of physical activity in the United States appear to have risen, but so too have obesity rates. The most likely explanation for this finding is that the rise in average physical activity levels has been outstripped by the excess of energy provided by the food supply. The message is plain – the primary driver of the obesity epidemic in the United States is now the food supply, and interventions targeting physical activity are not going to resolve it. So, while physical activity will benefit the health of the population even if it is not accompanied by weight loss [5],

Building a Basis for Action: Enhancing Public Health Surveillance of Vision Impairment and Eye Health in the United States

Potential competing interests: The author(s) declared that no potential competing

A new model for translational research and drug repositioning has recently been established based on three-way partnerships between public funders, the pharmaceutical industry and academic investigators. Through two pioneering initiatives - one involving the Medical Research Council in the United Kingdom and one involving the National Center for Advancing Translational Sciences of the National Institutes of Health in the United States - new investigations of highly characterized investigational compounds have been funded and are leading to the exploration of known mechanisms in new disease areas. This model has been extended beyond these first two initiatives. Here, we discuss the progress to date and the unique requirements and challenges for this model.

Disease prevention as social change: The state, society, and public health in the United States, France, Great Britain, and Canada, by Constance A. Nathanson, New York, Russell Sage Foundation, 200...