Standards-based physical education in schools: The role of state laws.

Purpose: Examine the association of state physical education (PE) laws (https://class.cancer.gov) with school policies addressing motor skill development, physical activity (PA) participation, and health-enhancing physical fitness (https://www.cdc.gov/healthyyouth/data/shpps/data.htm). Methods: National school-level data on PE standards were obtained from the 2014 School Health Policies and Practices Study (SHPPS) of US schools for analytical samples of 408-410 schools in 43 states. These data were linked to Classification of Laws Associated with School Students (CLASS) data, which reflect the strength of state-PE curriculum laws and the associated state PE curriculum standards. Logistic regressions and generalized linear models with a complementary log-log link examined associations between state law and school-level standards. Results: Compared to having no state law, weak law (OR: 5.07, 95% CI: 1.02-25.27) or strong law (OR: 2.96, 95% CI: 1.04-8.37) was associated with higher odds of school PE standards addressing motor skill development, while only strong state law was associated with higher prevalence of addressing achievement and maintenance of physical fitness (coefficient: 0.63, 95% CI: 0.12, 1.14). State laws were not associated with addressing PA participation. Conclusions: Schools were more likely to address motor skills and physical fitness development when states had strong PE laws.

Diet and Physical Activity Prevention Research Supported by the U.S. NIH From 2012-2017.

INTRODUCTION: Poor diet and inadequate physical activity are common contributors to preventable death in the U.S. This paper provides a summary of the NIH-sponsored research on disease prevention that underlies public health and clinical recommendations to improve diet and physical activity. METHODS: A representative sample (n=11,082) of research grants and cooperative agreements (research projects) representing the NIH prevention research portfolio between 2012 and 2017 were hand coded by trained analysts in 2017-2018. This manuscript describes the rationale(s), exposure(s), outcome(s), population(s), and study design(s) in prevention research focused on diet and physical activity and compares this research to identified research gaps in the field. RESULTS: A relatively stable 7.8% (95% CI=7.0%, 8.8%) and 5.0% (95% CI=4.4%, 5.7%) of the NIH prevention research projects were focused on diet and physical activity, respectively, during 2012-2017. These projects often explored diet and physical activity together in the context of obesity, included observational studies, and focused on a general adult population. Few of these projects focused on development of improved assessment methods. Approximately 50% of these studies were related to research gaps identified by the 2015 Dietary or 2018 Physical Activity Guidelines Advisory Committee Scientific Reports. CONCLUSIONS: Opportunities exist for more engagement by NIH and scientific investigators in diet- and physical activity-focused prevention research, particularly around assessment and known research gaps.

Daily Step Counts for Measuring Physical Activity Exposure and Its Relation to Health.

PURPOSE: A systematic primary literature review was conducted to evaluate the relationship of physical activity-as measured by daily step counts-with all-cause mortality, cardiovascular disease mortality, incident cardiovascular disease, and type 2 diabetes mellitus; to evaluate the shape of dose-response relationships; and to interpret findings in the context of development of the Physical Activity Guidelines for Americans, Second Edition. METHODS: A primary literature search encompassing 2011 to March 2018 for existing literature reporting on these relationships was conducted. RESULTS: Eleven pertinent articles were identified. Seven longitudinal studies examined the relationship between daily step counts and mortality, disease incidence, or risk. Two studies examined objectively measured steps per day and all-cause mortality; one was restricted to a relatively small elderly population. One study examined cardiovascular events, defined as cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. The other four longitudinal studies addressed incident type 2 diabetes. All longitudinal studies reported an inverse relationship between steps per day and outcome risk. In one study, 531 cardiovascular events occurred during more than 45,000 person-years of follow-up. Before intervention, each increment of 2000 steps per day up to 10,000 steps was associated with a 10% lower cardiovascular event rate. Also, for every increase of 2000 steps per day over baseline, there was an 8% yearly reduction in cardiovascular event rate in individuals with impaired glucose tolerance. CONCLUSIONS: Daily step count is a readily accessible means by which to monitor and set physical activity goals. Recent evidence supports previously limited evidence of an inverse dose-response relationship of daily steps with important health outcomes, including all-cause mortality, cardiovascular events, and type 2 diabetes. However, more independent studies will be required before these observations can be translated into public health guidelines.

Association between Bout Duration of Physical Activity and Health: Systematic Review.

PURPOSE: This study aimed to conduct a systematic literature review to determine whether physical activity episodes of <10 min in duration have health-related benefits or, alternatively, if the benefits are only realized when the duration of physical activity episodes is ≥10 min. METHODS: The primary literature search was conducted for the 2018 Physical Activity Guidelines Advisory Committee Report and encompassed literature through June 2017, with an additional literature search conducted to include literature published through March 2018 for inclusion in this systematic review. RESULTS: The literature review identified 29 articles that were pertinent to the research question that used either cross-sectional, prospective cohort, or randomized designs. One prospective cohort study (N = 4840) reported similar associations between moderate to vigorous physical activity (MVPA) and all-cause mortality when examined as total MVPA, MVPA in bouts ≥5 min in duration, or MVPA in bouts ≥10 min in duration. Additional evidence was identified from cross-sectional and prospective studies to support that bouts of physical activity <10 min in duration are associated with a variety of health outcomes. Randomized studies only examined bouts of physical activity ≥10 min in duration. CONCLUSIONS: The current evidence, from cross-sectional and prospective cohort studies, supports that physical activity of any bout duration is associated with improved health outcomes, which includes all-cause mortality. This may suggest the need for a contemporary paradigm shift in public health recommendations for physical activity, which supports total MVPA as an important lifestyle behavior regardless of the bout duration.

High-Intensity Interval Training for Cardiometabolic Disease Prevention.

PURPOSE: The 2018 Physical Activity Guidelines Advisory Committee systematically searched existing literature reviews to assess the relationship between high-intensity interval training (HIIT) and reduction in cardiometabolic disease risk. METHODS: Duplicate independent screenings of 260 articles identified from PubMed®, Cochrane Library, and CINAHL databases yielded suitable data from one systematic review and two meta-analyses. Search terms included a combination of "high intensity" "physical activity/exercise" and "interval training" and outcome-specific terms. The quality of the included reviews was assessed using a tailored version of the AMSTARExBP report on quality. Exposure Subcommittee members graded scientific evidence strength based on a five-criteria rubric and assigned one of four grades: strong, moderate, limited, or not assignable. RESULTS: Moderate evidence indicates that HIIT can improve insulin sensitivity, blood pressure, and body composition in adults with group mean ages ranging from ~20 to ~77 yr. These HIIT-induced improvements in cardiometabolic disease risk factors are comparable with those resulting from moderate-intensity continuous training, and they are more likely to occur in adults at higher risk of cardiovascular disease and diabetes than in healthy adults. Moderate evidence also indicates that adults with overweight or obesity classification are more responsive than adults with normal weight to HIIT-related improvements in insulin sensitivity, blood pressure, and body composition. Insufficient evidence was available to determine whether a dose-response relationship exists between the quantity of HIIT performed and several risk factors for cardiovascular disease and diabetes, or whether the effects of HIIT on cardiometabolic disease risk factors are influenced by age, sex, race/ethnicity, or socioeconomic status. CONCLUSIONS: HIIT by adults, especially those with overweight and obesity classification, can improve insulin sensitivity, blood pressure, and body composition, comparable with those resulting from moderate-intensity continuous training.

Physical Activity, All-Cause and Cardiovascular Mortality, and Cardiovascular Disease.

PURPOSE: Conduct a systematic umbrella review to evaluate the relationship of physical activity (PA) with all-cause mortality, cardiovascular mortality, and incident cardiovascular disease (CVD); to evaluate the shape of the dose-response relationships; and to evaluate these relationships relative to the 2008 Physical Activity Guidelines Advisory Committee Report. METHODS: Primary search encompassing 2006 to March, 2018 for existing systematic reviews, meta-analyses, and pooled analyses reporting on these relationships. Graded the strength of evidence using a matrix developed for the Physical Activity Guidelines Advisory Committee. RESULTS: The association of self-reported moderate-to-vigorous physical activity (MVPA) on all-cause mortality, CVD mortality, and atherosclerotic CVD-including incident coronary heart disease, ischemic stroke and heart failure-are very similar. Increasing MVPA to guidelines amounts in the inactive US population has the potential to have an important and substantial positive impact on these outcomes in the adult population. The following points are clear: the associations of PA with beneficial health outcomes begin when adopting very modest (one-third of guidelines) amounts; any MVPA is better than none; meeting the 2008 PA guidelines reduces mortality and CVD risk to about 75% of the maximal benefit obtained by physical activity alone; PA amounts beyond guidelines recommendations amount reduces risk even more, but greater amounts of PA are required to obtain smaller health benefits; and there is no evidence of excess risk over the maximal effect observed at about three to five times the amounts associated with current guidelines. When PA is quantified in terms of energy expenditure (MET·h·wk), these relationships hold for walking, running, and biking. CONCLUSIONS: To avoid the risks associated with premature mortality and the development of ischemic heart disease, ischemic stroke, and all-cause heart failure, all adults should strive to reach the 2008 Physical Activity Guidelines for Americans.

Benefits of Physical Activity during Pregnancy and Postpartum: An Umbrella Review.

PURPOSE: This study aimed to summarize the evidence from the 2018 Physical Activity Guidelines Advisory Committee Scientific Report, including new evidence from an updated search of the effects of physical activity on maternal health during pregnancy and postpartum. METHODS: An initial search was undertaken to identify systematic reviews and meta-analyses published between 2006 and 2016. An updated search then identified additional systematic reviews and meta-analyses published between January 2017 and February 2018. The searches were conducted in PubMed®, CINAHL, and Cochrane Library and supplemented through hand searches of reference lists of included articles and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: The original and updated searches yielded a total of 76 systematic reviews and meta-analyses. Strong evidence demonstrated that moderate-intensity physical activity reduced the risk of excessive gestational weight gain, gestational diabetes, and symptoms of postpartum depression. Limited evidence suggested an inverse relationship between physical activity and risk of preeclampsia, gestational hypertension, and antenatal anxiety and depressive symptomology. Insufficient evidence was available to determine the effect of physical activity on postpartum weight loss, postpartum anxiety, and affect during both pregnancy and postpartum. For all health outcomes, there was insufficient evidence to determine whether the relationships varied by age, race/ethnicity, socioeconomic status, or prepregnancy weight status. CONCLUSIONS: The gestational period is an opportunity to promote positive health behaviors that can have both short- and long-term benefits for the mother. Given the low prevalence of physical activity in young women in general, and the high prevalence of obesity and cardiometabolic diseases among the U.S. population, the public health importance of increasing physical activity in women of childbearing age before, during, and after pregnancy is substantial.

Effects of Physical Activity in Knee and Hip Osteoarthritis: A Systematic Umbrella Review.

INTRODUCTION: We conducted a systematic umbrella review to evaluate the literature relating to effects of physical activity on pain, physical function, health-related quality of life, comorbid conditions and osteoarthritis (OA) structural disease progression in individuals with lower-extremity OA. METHODS: Our primary search encompassed 2011 to February 2018 for existing systematic reviews (SR), meta-analyses (MA) and pooled analyses dealing with physical activity including exercise (not mixed with any other intervention and compared to a no-activity control group). A supplementary search encompassed 2006 to February 2018 for original research related to physical activity (including exercise) and lower limb OA progression. Study characteristics were abstracted, and risk of bias was assessed. RESULTS: Physical activity decreased pain and improved physical function (strong evidence) and improved health-related quality of life (moderate evidence) among people with hip or knee OA relative to less active adults with OA. There was no evidence to suggest accelerated OA progression for physical activity below 10,000 steps per day. Both physical activity equivalent to the 2008 Physical Activity Guidelines for Americans (150 min·wk of moderate-intensity exercise in bouts ≥10 min) and lower levels of physical activity (at least 45 total minutes per week of moderate-intensity) were associated with improved or sustained high function. No SR/MA addressing comorbid conditions in OA were found. Measurable benefits of physical activity appeared to persist for periods of up to 6 months following cessation of a defined program. CONCLUSIONS: People with lower-extremity OA should be encouraged to engage in achievable amounts of physical activity, of even modest intensities. They can choose to accrue minutes of physical activity throughout the entire day, irrespective of bout duration, and be confident in gaining some health and arthritis-related benefits.