Physical Activity and Body Mass Index of Children in an Old Order Amish Community

Exploring the relationship between neighborhood walkability and mental health: A study of urban areas in Texas

Background

While importance of walkable neighborhoods for health is increasingly recognized, the relationship between walkability and mental health remains, especially in urban settings, unclear. This study investigated the link between walkability and mental health in urban Texas. We hypothesized that higher neighborhood walkability would correlate with lower mental health encounters.

Methods

A cross-sectional study using Texas adult outpatient encounters from 2014 to 2019 supplemented by ZIP Code-level US-census socioeconomics data. Neighborhood walkability was assessed using the 2019-WalkScore (0-100) and was categorized into four groups: from completely car-dependent to very walkable/walker's paradise. Outpatient mental health encounters included depression, bipolar disorder, anxiety, and stress disorders. Generalized linear models were used to assess the association between walkability and mental health, while adjusting for demographics and socioeconomics.

Results

We included 55 million encounters from 751 Texas ZIP Codes (median WalkScore 28, 73 % < 65 years, 64 % women, 15 % Blacks, 16 % Hispanics, 15 % live in poverty, and 17 % without health insurance). Anxiety/stress disorders contributed to 68 % of the mental health encounters. The rate of mental health encounters was at least 3 times higher (5543 vs 1827 encounters per 100,000 population) (RR 3.03, 95%CI 1.53-6.03) in urban areas with the highest WalkScores, compared to lowest walkability neighborhoods. A similar pattern was found among depression (RR 4.8, 95%CI 2.45-9.46) and bipolar (RR 10.8, 95%CI 4.17-28.07) encounters. After adjusting for demographic and socioeconomic factors, the positive association remained significant for both depression (aRR 1.94, 95%CI 1.19-3.17) and bipolar (aRR 2.76, 95%CI 1.65-4.65) encounters, but not for total mental health encounters (aRR 1.22, 95%CI 0.76-1.96, P = 0.416).

Conclusion

The study findings challenge our initial hypothesis, revealing a positive association between neighborhood walkability and various mental health encounters, emphasizing the complex intersection between urban environment and mental health. This suggests that walkability does not solely determine mental health outcomes. A deeper understanding of how demographics, socioeconomic factors, and neighborhood characteristics interact is essential to inform policies that create more equitable mentally-healthy cities.

Exercise and Experiments of Nature

In this article, we highlight the contributions of passive experiments that address important exercise-related questions in integrative physiology and medicine. Passive experiments differ from active experiments in that passive experiments involve limited or no active intervention to generate observations and test hypotheses. Experiments of nature and natural experiments are two types of passive experiments. Experiments of nature include research participants with rare genetic or acquired conditions that facilitate exploration of specific physiological mechanisms. In this way, experiments of nature are parallel to classical "knockout" animal models among human research participants. Natural experiments are gleaned from data sets that allow population-based questions to be addressed. An advantage of both types of passive experiments is that more extreme and/or prolonged exposures to physiological and behavioral stimuli are possible in humans. In this article, we discuss a number of key passive experiments that have generated foundational medical knowledge or mechanistic physiological insights related to exercise. Both natural experiments and experiments of nature will be essential to generate and test hypotheses about the limits of human adaptability to stressors like exercise. © 2023 American Physiological Society. Compr Physiol 13:4879-4907, 2023.

Physical health conditions of the Amish and intervening social mechanisms: an exhaustive narrative review

As an ethnic religion, the Amish are of interest to population health researchers due to a distinctive health profile arising from ethnic attributes, including a closed genetic pool and shared culture that shapes lifestyle practices. Amish-focused health research both furthers our knowledge of health conditions by comparing Amish with non-Amish and assists health practitioners in serving this rapidly growing population. Amish health research, now representing approximately a quarter of all Amish-focused publications, is in need of review, to the end of strengthening this knowledge body's coherence, clarifying research directions, and identifying knowledge gaps, lapses, and stagnations. Herein, we synthesize and discuss Amish physical health conditions research, both the population's distinctive health profile and mechanisms shaping this profile. Specifically, we summarize research addressing BMI, physical activity, and body image; diet and supplements; cancer; cardiovascular conditions; communicable diseases; immunity; sleep; genetic disorders; tobacco and alcohol use; periodontal conditions; traumatic injuries; natural treatments for burns; fertility; and sexually transmitted diseases. In reflection, we raise questions about the nature of intervening mechanisms shaping the Amish health profile, the strange omission of several common independent variables commonly used when studying other ethnic groups' health, several recurring methodological complications, and public health policy considerations.

Exploring non-linear relationships between neighbourhood walkability and health: a cross-sectional study among US primary care patients with chronic conditions

BACKGROUND

A recent study of licensed drivers found a non-linear relationship between density of non-residential destinations (NRDs), a proxy for walkability and body mass index (BMI) across a wide range of development patterns. It is unclear if this relationship can be replicated in a population with multiple chronic conditions or translated to health outcomes other than BMI.

METHODS

We obtained health data and home addresses for 2405 adults with multiple chronic conditions from 44 primary care clinics across 13 states using the Integrating Behavioral health and Primary Care Trial. In this cross-sectional study, the relationships between density of NRDs (from a commercial database) within 1 km of the home address and self-reported BMI, and mental and physical health indices were assessed using several non-linear methods, including restricted cubic splines, LOWESS smoothing curves, non-parametric regression with a spline basis and piecewise linear regression.

RESULTS

All methods demonstrated similar non-linear relationships. Piecewise linear regression was selected for ease of interpretation. BMI had a positive marginal rate of change below the NRD density inflection point of 15 establishments/hectare (β=+0.09 kg/m²/non-residential buildings ha-1; 95% CI +0.01 to +0.14), and a negative marginal rate of change above the inflection point (β=-0.02; 95% CI -0.06 to 0.02). Mental health decreased with NRD density below the inflection point (β=-0.24; 95% CI -0.31 to -0.17) and increased above it (β=+0.03; 95% CI -0.00 to +0.07). Results were similar for physical health (β= -0.28; 95% CI -0.35 to -0.20) and (β=+0.06; 95% CI 0.01 to +0.10).

CONCLUSION

Health indicators were the lowest in middle density (typically suburban) areas and got progressively better moving in either direction from the peak. NRDs may affect health differently depending on home-address NRD density.

TRIAL REGISTRATION NUMBER

NCT02868983.

Time Trends in Physical Activity Using Wearable Devices: A Systematic Review and Meta-analysis of Studies from 1995 to 2017

INTRODUCTION

Conflicting evidence exists on whether physical activity (PA) levels of humans have changed over the last quarter-century. The main objective of this study was to determine if there is evidence of time trends in PA, from cross-sectional studies that assessed PA at different time points using wearable devices (e.g., pedometers and accelerometers). A secondary objective was to quantify the rate of change in PA.

METHODS

A systematic literature review was conducted of English-language studies indexed in PubMed, SPORTDiscus, and Web of Science (1960-2020) using search terms (time OR temporal OR secular) AND trends AND (steps per day OR pedometer OR accelerometer OR MVPA). Subsequently, a meta-analytic approach was used to aggregate data from multiple studies and to examine specific factors (i.e., sex, age-group, sex and age-group, and PA metric).

RESULTS

Based on 16 peer-reviewed scientific studies conducted between 1995 and 2017, levels of ambulatory PA are trending downward in developed countries. Significant declines were seen in both males and females (P < 0.001) as well as in children (P = 0.020), adolescents (P < 0.001), and adults (P = 0.004). The average study duration was 9.4 yr (accelerometer studies, 5.3 yr; pedometer studies, 10.8 yr). For studies that assessed steps, the average change in PA was -1118 steps per day over the course of the study (P < 0.001), and adolescents had the greatest change in PA at -2278 steps per day (P < 0.001). Adolescents also had the steepest rate of change over time, expressed in steps per day per decade.

CONCLUSIONS

Evidence from studies conducted in eight developed nations over a 22-yr period indicates that PA levels have declined overall, especially in adolescents. This study emphasizes the need for continued research tracking time trends in PA using wearable devices.

Nonlinear relationship between nonresidential destinations and body mass index across a wide range of development

BACKGROUND

Destination accessibility is an important measure of the built environment that is associated with active transport and body mass index (BMI). In higher density settings, an inverse association has been consistently found, but in lower density settings, findings are limited. We previously found a positive relationship between the density of nonresidential destinations (NRD) and BMI in a low-density state. We sought to test the generalizability of this unexpected finding using data from six other states that include a broader range of settlement densities.

METHODS

We obtained the address, height, and weight of 16.9 million residents with a driver's license or state identification cards, as well as the location of 3.8 million NRDs in Washington, Oregon, Texas, Illinois, Michigan, and Maine from Dun & Bradstreet. We tested the association between NRDs∙ha^-1 within 1 km of the home address, and self-reported BMI (kg∙m^-2). Visualization by locally-weighted smoothing curves (LOWESS) revealed an inverted U-shape. A multivariable piecewise regression with a random intercept for state was used to assess the relationship.

RESULTS

After accounting for age, sex, year of issue, and census tract social and economic variables, BMI correlated positively with NRDs in the low-to-mid density stratum (β = +0.005 kg∙m^-2/nonresidential building∙ha^-1; 95% CI: +0.004,+0.006) and negatively in the mid-to-high density stratum (β = -0.002; 95% CI: -0.004,-0.0003); a significant difference in slopes (P < 0.001).

CONCLUSIONS

BMI peaked in the middle density, with lower values in both the low and high-density extremes. These results suggest that the mechanisms by which NRDs are associated with obesity may differ by density level.

Workload Accomplished in Phase III Cardiac Rehabilitation

Exercise training is an important component of clinical exercise programs. Although there are recognized guidelines for the amount of exercise to be accomplished (≥70,000 steps per week or ≥150 min per week at moderate intensity), there is virtually no documentation of how much exercise is actually accomplished in contemporary exercise programs. Having guidelines without evidence of whether they are being met is of limited value. We analyzed both the weekly step count and the session rating of perceived exertion (sRPE) of patients (n = 26) enrolled in a community clinical exercise (e.g., Phase III) program over a 3-week reference period. Step counts averaged 39,818 ± 18,612 per week, with 18% of the steps accomplished in the program and 82% of steps accomplished outside the program. Using the sRPE method, inside the program, the patients averaged 162.4 ± 93.1 min per week, at a sRPE of 12.5 ± 1.9 and a frequency of 1.8 ± 0.7 times per week, for a calculated exercise load of 2042.5 ± 1244.9 AU. Outside the program, the patients averaged 144.9 ± 126.4 min, at a sRPE of 11.8 ± 5.8 and a frequency of 2.4 ± 1.5 times per week, for a calculated exercise load of 1723.9 ± 1526.2 AU. The total exercise load using sRPE was 266.4 ± 170.8 min per week, at a sRPE of 12.6 ± 3.8, and frequency of 4.2 ± 1.1 times per week, for a calculated exercise load of 3359.8 ± 2145.9 AU. There was a non-linear relationship between steps per week and the sRPE derived training load, apparently attributable to the amount of non-walking exercise accomplished in the program. The results suggest that patients in a community clinical exercise program are achieving American College of Sports Medicine guidelines, based on the sRPE method, but are accomplishing less steps than recommended by guidelines.

Prevalence, control, and treatment of diabetes, hypertension, and high cholesterol in the Amish

BACKGROUND

The burden of diabetes and cardiovascular risk is not uniform across the USA, with much of this disparity tracking differences in socioeconomic status, cultural practices and lifestyle. To further evaluate disparities in these disorders, we assessed the prevalence of diabetes, hypertension, and hypercholesterolemia in an Old Order Amish community that is characterized by distinctive sociocultural practices that include a very cohesive social structure and limited use of modern technologies and medications. We compared prevalence of these conditions with that of the overall US population.

METHOD

We performed a community-wide survey in 5377 Amish individuals aged 18 years and older from the Lancaster County, Pennsylvania, Amish settlement that included a basic physical examination and fasting blood draw during the period 2010-2018. We then compared the prevalence of diabetes, hypertension, and high cholesterol, defined using standard criteria, between the Amish and the European Caucasian subsample of the 2013-2014 US National Health and Nutrition Examination Survey (NHANES).

RESULTS

Prevalence rates for diabetes, hypertension and hypercholesterolemia were 3.3%, 12.7%, and 26.2% in the Amish compared with 13.2%, 37.8% and 35.7% in NHANES (p<0.001 for all). Among individuals with these disorders, Amish were less likely to be aware that they were affected, and among those aware, were less likely to be treated with a medication for their disorder.

CONCLUSION

There is substantially lower prevalence of diabetes, hypertension and hypercholesterolemia in the Amish compared with non-Amish Caucasians in the USA. Possible factors contributing to this disparity include higher physical activity levels in the Amish or other protective sociocultural factors, a greater understanding of which could inform risk reduction interventions for these chronic diseases.

Body mass index and movement behaviors among schoolchildren from 13 countries across a continuum of human development indices: A multinational cross-sectional study

OBJECTIVE

This study describes the distributions of body mass index (BMI) and movement behaviors among schoolchildren from 13 countries across a continuum of human development.

METHODS

Data were from a cross-sectional study of 9-11-year-old children (n = 8055) recruited from 269 urban schools in 13 countries, and an additional 7 rural schools in one of these countries (Mozambique). BMI was derived from objectively measured heights and weights. Moderate- to vigorous-intensity physical activity (MVPA), sedentary time (SED), and sleep duration were assessed by waist-worn Actigraph GT3X+ accelerometers. Linear models were used to describe the distributions of BMI z-scores, MVPA, SED, and sleep among sites across varying Human Development Indices (HDIs).

RESULTS

Mean MVPA, SED, and sleep duration were 63.1 ± 27.3 minutes/day, 508.7 ± 72.4 minutes/day, and 8.8 ± 0.9 hours/night, respectively. Overall, 2.1% of the sample were thin, 19.5% overweight, and 11.7% were obese. Density curves (BMI z-scores and SED) for urban children in Mozambique showed significantly higher mean values compared with rural children. Boys had significantly higher mean MVPA compared with girls. Mean BMI z-scores were positively associated (β = .02; P = .004) with HDI, mean daily MVPA minutes were negatively associated (β = -.38; P = .025) with HDI, and mean SED time was positively associated with HDI (β = 1.18; P = .049). No significant association (β = .01; P = .29) was observed between sleep duration and HDI.

CONCLUSION

Our findings show distinct differences in BMI and movement behavior profiles between urban and rural children in Mozambique. Mean BMI z-scores, MVPA, and SED differed by country HDI. These findings support the need to include both rural and urban participants in study samples.

Comparisons of pedometer-determined weekday physical activity among Swedish school children and adolescents in 2000 and 2017 showed the highest reductions in adolescents

AIM

This study compared differences in weekday physical activity among school children and adolescents in middle-class communities in south-eastern Sweden in 2000 and 2017.

METHODS

Data were drawn from two independent cross-sectional cohorts of children and adolescents aged 8, 11 and 14. The same six schools, protocols, procedures and instruments were used in both years, with 332 subjects in 2000 and 562 in 2017. Mean steps per day (SPD) were measured with a Yamax SW-200 pedometer.

RESULTS

The mean weekday SPD was similar among eight-year-old girls in both years, but 8% (p = 0.040) higher among eight-year-old boys in 2017. However, among 11-year-old children, the mean SPD were 12% lower among both girls (p = 0.033) and boys (p = 0.001). The SPD among 14-year-old adolescents were 24% (p = 0.012) and 30% (p < 0.001) lower among girls and boys, respectively.

CONCLUSION

This school-based study from south-eastern Sweden showed that weekday physical activity differed between age groups in 2000 and 2017. The highest reductions were seen among older children and adolescents, particularly 14-year-old girls and boys. The only group that increased was eight-year-old boys, with no significant change in eight-year-old girls. A possible explanation might be the dramatically increased use of the Internet on phones and tablets.

Increased usual physical activity is associated with a blunting of the triglyceride response to a high-fat meal

BACKGROUND

Postprandial lipemia (PPL), defined as a prolonged or elevated rise in triglycerides that accompanies fat feeding, is a significant risk factor for coronary heart disease and associated comorbidities. The impact of PPL on coronary heart disease risk is underscored by the preponderance of each day spent in the postprandial state.

OBJECTIVE

In this study, we evaluated cross-sectionally the association between usual (ie, noninterventional) physical activity and the 6-hour triglyceride response to a standardized high-fat meal.

METHODS

The high-fat meal intervention was carried out in 671 apparently healthy individuals as part of the Heredity and Phenotype Intervention Heart Study. Triglyceride levels were measured in the fasting state and during 6 hours after administration of a standardized fat challenge. We defined PPL response as the triglyceride area under the fat load curve (AUC) and measured physical activity using accelerometers that were worn continuously over a 7-day period.

RESULTS

Physical activity levels decreased with increasing age and were higher in men than women (both P < .001). The triglyceride AUC increased with increasing age in both men and women (both P < .001) and was also higher in men than in women (age-adjusted P = 9.2 × 10^-12). Higher physical activity levels were associated with a lower triglyceride AUC (P = .003), adjusting for age, sex, body mass index, and fasting low-density lipoprotein.

CONCLUSION

These results suggest that the protective benefits of physical activity on cardiovascular health may operate, at least in part, through reduction of the PPL triglyceride response.

The impact of Nordic walking training on the gait of the elderly

The purpose of the current study was to define the impact of regular practice of Nordic walking on the gait of the elderly. Thereby, we aimed to determine whether the gait characteristics of active elderly persons practicing Nordic walking are more similar to healthy adults than that of the sedentary elderly. Comparison was made based on parameters computed from three inertial sensors during walking at a freely chosen velocity. Results showed differences in gait pattern in terms of the amplitude computed from acceleration and angular velocity at the lumbar region (root mean square), the distribution (Skewness) quantified from the vertical and Euclidean norm of the lumbar acceleration, the complexity (Sample Entropy) of the mediolateral component of lumbar angular velocity and the Euclidean norm of the shank acceleration and angular velocity, the regularity of the lower limbs, the spatiotemporal parameters and the variability (standard deviation) of stance and stride durations. These findings reveal that the pattern of active elderly differs significantly from sedentary elderly of the same age while similarity was observed between the active elderly and healthy adults. These results advance that regular physical activity such as Nordic walking may counteract the deterioration of gait quality that occurs with aging.

Role of Inactivity in Chronic Diseases: Evolutionary Insight and Pathophysiological Mechanisms

This review proposes that physical inactivity could be considered a behavior selected by evolution for resting, and also selected to be reinforcing in life-threatening situations in which exercise would be dangerous. Underlying the notion are human twin studies and animal selective breeding studies, both of which provide indirect evidence for the existence of genes for physical inactivity. Approximately 86% of the 325 million in the United States (U.S.) population achieve less than the U.S. Government and World Health Organization guidelines for daily physical activity for health. Although underappreciated, physical inactivity is an actual contributing cause to at least 35 unhealthy conditions, including the majority of the 10 leading causes of death in the U.S. First, we introduce nine physical inactivity-related themes. Next, characteristics and models of physical inactivity are presented. Following next are individual examples of phenotypes, organ systems, and diseases that are impacted by physical inactivity, including behavior, central nervous system, cardiorespiratory fitness, metabolism, adipose tissue, skeletal muscle, bone, immunity, digestion, and cancer. Importantly, physical inactivity, itself, often plays an independent role as a direct cause of speeding the losses of cardiovascular and strength fitness, shortening of healthspan, and lowering of the age for the onset of the first chronic disease, which in turn decreases quality of life, increases health care costs, and accelerates mortality risk.

Decline in objective physical activity over a 10-year period in a Japanese elementary school

Background

The purpose of this study was to examine the change in accelerometer-derived daily physical activity (PA) and activity record-derived daily activities over a 10-year period in urban elementary schoolchildren in Japan.

Methods

A total of 233 sixth-grade children (11–12 years old) in a same elementary school in Kyoto participated in the study (n = 125 and 108 in 1999 and 2009, respectively). The participant rate is 91.9 and 98.2 % in 1999 and 2009, respectively. The size and shape of the school district was not changed. The children were instructed to wear an accelerometer for 5 consecutive days of weekday and to keep minute-by-minute 24-h activity records with the assistance of their parents. The school-day scheduling was similar between 1999 and 2009 (29 and 27 sessions of 45-min class per week, respectively).

Results

From 1999 to 2009, step counts considerably decreased (20,832 vs. 12,237 steps per day in boys and 16,087 vs. 10,748 steps per day in girls; P < 0.001) with concomitant significant decreases in total energy expenditure (P = 0.011), activity energy expenditure (P < 0.001), and physical activity level (P < 0.001). Time spent playing outdoors and walking to school were also significantly less in 2009 than 1999 (P < 0.001). Accelerometer-measured PA was significantly associated with the amount of time spent playing outdoors and walking to school.

Conclusions

These results indicate that elementary schoolchildren in 2009 spend less time playing outdoors and walking to school, perform less PA, and take fewer steps than children of a decade ago.

Iron metabolism in obesity: how interaction between homoeostatic mechanisms can interfere with their original purpose. Part II: epidemiological and historic aspects of the iron/obesity interaction

The change from a mainly vegetarian fare to meat consumption went along with brain growth and increased insulin resistance to improve brain's glucose supply. Meat consumption increased iron bioavailability and, thus, physical and mental fitness. The "predation-release-hypothesis" proposes that group coordination, arms and fire abolished the survival advantage of lean individuals from predation. The "thrifty gene-hypothesis", in contrast, proposes that surviving repeated episodes of starvation increased efficiency of food utilization in the offspring; they learned to utilize every available calorie. As a consequence of either mechanism, improved food security will increase prevalence of obesity along with that of its fatal consequences, such as diabetes, hypertension, heart diseases, and cancer. Thus, improved food security collides with the biologically evolved mechanisms to store excessive calories in preparation for a famine that never came. The crash between homoeostatic mechanisms and human intervention caused the presently observed pandemia of obesity and explains why it is so difficult to avoid, in spite of its well known and often fatal consequences.

Health benefits of Nordic walking: a systematic review

CONTEXT

Modern lifestyle, with its lack of everyday physical activity and exercise training, predisposes people to chronic diseases such as diabetes mellitus, obesity, hypertension, and coronary artery diseases. Brisk walking as a simple and safe form of exercise is undisputedly an effective measure to counteract sedentary lifestyle risks even in the most unfit and could lead to a reduction of the prevalence of chronic diseases in all populations. The purpose of this review is to systematically summarize, analyze, and interpret the health benefits of Nordic walking (walking with poles), and to compare it to brisk walking and jogging.

EVIDENCE ACQUISITION

A systematic and comprehensive literature search was performed between November 2010 and May 2012. Data were analyzed between April 2011 and May 2012.

EVIDENCE SYNTHESIS

Sixteen RCTs with a total of 1062 patients and 11 observational studies with 831 patients were identified. The current analysis revealed that with regard to short- and long-term effects on heart rate, oxygen consumption, quality of life, and other measures, Nordic walking is superior to brisk walking without poles and in some endpoints to jogging.

CONCLUSIONS

Nordic walking exerts beneficial effects on resting heart rate, blood pressure, exercise capacity, maximal oxygen consumption, and quality of life in patients with various diseases and can thus be recommended to a wide range of people as primary and secondary prevention.

Physical activity, energy intake, and obesity prevalence among urban and rural schoolchildren aged 11–12 years in Japan

The prevalence of childhood overweight and obesity has been shown to differ among regions, including rural–urban regional differences within nations. This study obtained simultaneous accelerometry-derived physical activity, 24 h activity, and food records to clarify the potential contributing factors to rural–urban differences in childhood overweight and obesity in Japan. Sixth-grade children (n = 227, 11–12 years old) from two urban elementary schools in Kyoto and four rural elementary schools in Tohoku participated in the study. The children were instructed to wear a pedometer that included a uniaxial accelerometer and, assisted by their parents, keep minute-by-minute 24 h activity and food records. For 12 children, the total energy expenditure was measured by the doubly labeled water method that was used to correct the Lifecorder-predicted activity energy expenditure and physical activity level. The overweight and obesity prevalence was significantly higher in rural than in urban children. The number of steps per day, activity energy expenditure, physical activity level, and duration of walking to school were significantly lower in rural than in urban children. In contrast, the reported energy intake did not differ significantly between the regions. The physical activity and duration of the walk to school were significantly correlated with body mass index. Rural children had a higher prevalence of overweight and obesity, and this may be at least partly caused by lower physical activity, especially less time spent walking to school, than urban children.

A step-defined sedentary lifestyle index: <5000 steps/day

Step counting (using pedometers or accelerometers) is widely accepted by researchers, practitioners, and the general public. Given the mounting evidence of the link between low steps/day and time spent in sedentary behaviours, how few steps/day some populations actually perform, and the growing interest in the potentially deleterious effects of excessive sedentary behaviours on health, an emerging question is "How many steps/day are too few?" This review examines the utility, appropriateness, and limitations of using a reoccurring candidate for a step-defined sedentary lifestyle index: <5000 steps/day. Adults taking <5000 steps/day are more likely to have a lower household income and be female, older, of African-American vs. European-American heritage, a current vs. never smoker, and (or) living with chronic disease and (or) disability. Little is known about how contextual factors (e.g., built environment) foster such low levels of step-defined physical activity. Unfavorable indicators of body composition and cardiometabolic risk have been consistently associated with taking <5000 steps/day. The acute transition (3-14 days) of healthy active young people from higher (>10 000) to lower (<5000 or as low as 1500) daily step counts induces reduced insulin sensitivity and glycemic control, increased adiposity, and other negative changes in health parameters. Although few alternative values have been considered, the continued use of <5000 steps/day as a step-defined sedentary lifestyle index for adults is appropriate for researchers and practitioners and for communicating with the general public. There is little evidence to advocate any specific value indicative of a step-defined sedentary lifestyle index in children and adolescents.

Device-based monitoring in physical activity and public health research

Measurement of physical activity is important, given the vital role of this behavior in physical and mental health. Over the past quarter of a century, the use of small, non-invasive, wearable monitors to assess physical activity has become commonplace. This review is divided into three sections. In the first section, a brief history of physical activity monitoring is provided, along with a discussion of the strengths and weaknesses of different devices. In the second section, recent applications of physical activity monitoring in physical activity and public health research are discussed. Wearable monitors are being used to conduct surveillance, and to determine the extent and distribution of physical activity and sedentary behaviors in populations around the world. They have been used to help clarify the dose-response relation between physical activity and health. Wearable monitors that provide feedback to users have also been used in longitudinal interventions to motivate research participants and to assess their compliance with program goals. In the third section, future directions for research in physical activity monitoring are discussed. It is likely that new developments in wearable monitors will lead to greater accuracy and improved ease-of-use.

Physical activity classification using the GENEA wrist-worn accelerometer

INTRODUCTION

Most accelerometer-based activity monitors are worn on the waist or lower back for assessment of habitual physical activity. Output is in arbitrary counts that can be classified by activity intensity according to published thresholds. The purpose of this study was to develop methods to classify physical activities into walking, running, household, or sedentary activities based on raw acceleration data from the GENEA (Gravity Estimator of Normal Everyday Activity) and compare classification accuracy from a wrist-worn GENEA with a waist-worn GENEA.

METHODS

Sixty participants (age = 49.4 ± 6.5 yr, body mass index = 24.6 ± 3.4 kg·m⁻²) completed an ordered series of 10-12 semistructured activities in the laboratory and outdoor environment. Throughout, three GENEA accelerometers were worn: one at the waist, one on the left wrist, and one on the right wrist. Acceleration data were collected at 80 Hz. Features obtained from both fast Fourier transform and wavelet decomposition were extracted, and machine learning algorithms were used to classify four types of daily activities including sedentary, household, walking, and running activities.

RESULTS

The computational results demonstrated that the algorithm we developed can accurately classify certain types of daily activities, with high overall classification accuracy for both waist-worn GENEA (0.99) and wrist-worn GENEA (right wrist = 0.97, left wrist = 0.96).

CONCLUSIONS

We have successfully developed algorithms suitable for use with wrist-worn accelerometers for detecting certain types of physical activities; the performance is comparable to waist-worn accelerometers for assessment of physical activity.

Importance of characteristics and modalities of physical activity and exercise in defining the benefits to cardiovascular health within the general population: recommendations from the EACPR (Part I)

Over the last decades, more and more evidence is accumulated that physical activity (PA) and exercise interventions are essential components in primary and secondary prevention for cardiovascular disease. However, it is less clear whether and which type of PA and exercise intervention (aerobic exercise, dynamic resistive exercise, or both) or characteristic of exercise (frequency, intensity, time or duration, and volume) would yield more benefit in achieving cardiovascular health. The present paper, as the first of a series of three, will make specific recommendations on the importance of these characteristics for cardiovascular health in the population at large. The guidance offered in this series of papers is aimed at medical doctors, health practitioners, kinesiologists, physiotherapists and exercise physiologists, politicians, public health policy makers, and the individual member of the public. Based on previous and the current literature, recommendations from the European Association on Cardiovascular Prevention and Rehabilitation are formulated regarding type, volume, and intensity of PA and exercise.

The forgotten face of regular physical exercise: a 'natural' anti-atherogenic activity

Humans are not programmed to be inactive. The combination of both accelerated sedentary lifestyle and constant food availability disturbs ancient metabolic processes leading to excessive storage of energy in tissue, dyslipidaemia and insulin resistance. As a consequence, the prevalence of Type 2 diabetes, obesity and the metabolic syndrome has increased significantly over the last 30 years. A low level of physical activity and decreased daily energy expenditure contribute to the increased risk of cardiovascular morbidity and mortality following atherosclerotic vascular damage. Physical inactivity leads to the accumulation of visceral fat and consequently the activation of the oxidative stress/inflammation cascade, which promotes the development of atherosclerosis. Considering physical activity as a 'natural' programmed state, it is assumed that it possesses atheroprotective properties. Exercise prevents plaque development and induces the regression of coronary stenosis. Furthermore, experimental studies have revealed that exercise prevents the conversion of plaques into a vulnerable phenotype, thus preventing the appearance of fatal lesions. Exercise promotes atheroprotection possibly by reducing or preventing oxidative stress and inflammation through at least two distinct pathways. Exercise, through laminar shear stress activation, down-regulates endothelial AT1R (angiotensin II type 1 receptor) expression, leading to decreases in NADPH oxidase activity and superoxide anion production, which in turn decreases ROS (reactive oxygen species) generation, and preserves endothelial NO bioavailability and its protective anti-atherogenic effects. Contracting skeletal muscle now emerges as a new organ that releases anti-inflammatory cytokines, such as IL-6 (interleukin-6). IL-6 inhibits TNF-α (tumour necrosis factor-α) production in adipose tissue and macrophages. The down-regulation of TNF-α induced by skeletal-muscle-derived IL-6 may also participate in mediating the atheroprotective effect of physical activity.

Can we modulate physical activity in children?

There is concern that interventions that use physical activity to prevent obesity in children might be undermined by an 'Activitystat', which exerts an effect to maintain a low set point for physical activity. The present critique summarises evidence from systematic reviews of interventions, from empirical tests of the Activitystat hypothesis, from studies on the heritability of physical activity in childhood and the physical activity of children of and adolescents across a wide range of physical and cultural environments. This body of evidence is inconsistent with the Activitystat hypothesis in its current form, and suggests that the emphasis on physical activity in obesity prevention interventions in children should be increased, not reduced.

A 10-month physical activity intervention improves body composition in young black boys

Objective. To determine if a 10-month after-school physical activity (PA) intervention could prevent deleterious changes in body composition and cardiovascular (CV) fitness in young black boys. Methods. Following baseline measures, 106 boys (8-12 yrs) were randomized to either a control group or an intervention group, further divided into attenders (ATT) and nonattenders (NATT), participating in ≥60% or <60% of the intervention, respectively. The daily intervention consisted of skills development (25 min), vigorous PA (VPA, 35 min), and strengthening/stretching (20 min) components. Body composition was measured by dual-energy X-ray absorptiometry. Results. Following the intervention, the ATT exhibited an increase in moderate-to-vigorous PA and a significant reduction in BMI, fat mass, and %BF compared to the control group. A significant association among the intervention energy expenditure and changes in body composition and CV fitness was observed only in the ATT group. Conclusion. An after-school PA program of sufficient length and intensity can promote healthy changes in body composition and fitness levels in black boys who attend at least 3 days/week.

Pedometer-measured physical activity patterns of youth: a 13-country review

CONTEXT

Insufficient physical activity among young people aged 5-18 years is a global public health issue, with considerable disparities among countries. A systematic review was conducted to identify studies reporting pedometer daily steps (steps x day(-1)) in order to compile comparative, global cross-sectional data on youth physical activity patterns.

EVIDENCE ACQUISITION

Articles were included if they were in English, published by April 2009, and reported steps x day(-1) for boys and girls, separately, and reported steps x day(-1) for age groupings of no more than 4 years (e.g., 5-8 years) or combined no more than three grade levels (e.g., third- to fifth-graders). Studies could have been intervention-based but had to have reported baseline steps x day(-1), which would reflect unadulterated physical activity steps x day(-1) estimates. Inverse variance weighted estimates (steps x day(-1w)) were calculated for each country, and random effects models were estimated. Analyses were conducted in May and June 2009.

EVIDENCE SYNTHESIS

Forty-three studies, representing young people in 13 countries (N=14,200), were included. The majority of studies were from the U.S. (17/43). Overall, there was considerable variation within and among countries in steps x day(-1w). Boys and girls from European and Western Pacific regions had significantly more steps x day(-1w) than young people from the U.S. and Canada. Significantly lower steps x day(-1w) estimates for girls were observed for studies that combined measured steps x day(-1) for weekdays and weekend days, in comparison to weekdays only.

CONCLUSIONS

Limited sample sizes and non-population-based data preclude definitive statements regarding projected steps x day(-1) within countries. Nevertheless, these findings provide preliminary information for policymakers and researchers on the extent of the disparities among countries in the physical activity patterns of young people.

School nurses and childhood obesity: an investigation of knowledge and practice among school nurses as they relate to childhood obesity

BACKGROUND

Childhood obesity has escalated to an alarming proportion in the last twenty years. It is currently the most preventable nutritional disease of the 21(st) century. Anecdotal literature suggests that school nurses play a pivotal role in the fight against the escalating incidence of childhood obesity. However, research has not clearly shown that school nurses engage in health promotion behaviors that combat childhood obesity.

METHODS

A convenience sample of 103 New Jersey school nurses who attended county school nurses association meetings were surveyed. A 55-item tool was used to measure school nurses' knowledge and practice regarding childhood obesity.

RESULTS

While ninety-nine percent of the nurses are aware that childhood obesity is becoming more prevalent, more than 35% of the school nurses reported a lack of competence in recommending weight-loss programs for children. More than 65% rated using age-specific BMI to calculate childhood obesity "sometimes," "rarely," or "never."

CONCLUSIONS

Data from this study indicates that New Jersey school nurses are knowledgeable regarding childhood obesity, yet many do not report levels of competence in recommending weight-loss treatment to promote healthy lifestyle choices for their students. Further research is needed to understand the barriers to health promotion practices among school nurses.

Increased obesity in children living in rural communities of Louisiana

OBJECTIVE

Rates of obesity among children have been rising in recent years. Information on the prevalence of obesity in children living in rural communities is needed. We report the prevalence of overweight and obesity in children enrolled in grades 4 to 6 who live in rural areas of Louisiana, USA.

METHODS AND PROCEDURES

These data were collected as baseline assessment for the Louisiana (LA) Health project. Height, weight, and estimates of body fat (using body impedance analysis) were collected on 2 709 children. Average age was 10.5 years and the sample composition was 57.3% girls, 61.7% African-American, 36.0% Caucasian, and 2.3% other minority. A majority of children (77%) met the criterion for poverty status.

RESULTS

The distribution of body mass index (BMI) percentile was highly skewed toward obesity. The most frequent BMI percentile scores were 98(th) and 99(th) percentile. Using Centers for Disease Control and Prevention (CDC) norms, the overall prevalence of obesity was 27.4%, and for overweight was 45.1%, of which 17.7% were between the 85(th) and 95(th) percentile. The prevalence of childhood overweight and obesity were much higher than the national norm and this increased prevalence was observed in both genders and in Caucasian and African-American children.

DISCUSSION

The prevalence of childhood overweight and obesity was found to be much higher in rural and primarily poor (77%) children living in Louisiana when compared with national norms. This observation suggests that rural children from Louisiana may be experiencing an epidemic of obesity that exceeds national prevalence estimates.

Elevated blood pressure in relation to overweight and obesity among children in a rural Canadian community

OBJECTIVE

Childhood overweight and obesity may result in premature onset of cardiovascular risk factors such as hypertension. Rural populations in North America may be at increased risk for overweight. We evaluated whether overweight and obesity were associated with prehypertension and hypertension in a well-characterized population of children in rural Canada.

METHODS

The study population for this cross-sectional study was composed of children (aged 4-17 years) who were participants of the Walkerton Health Study (Canada) in 2004. Prehypertension and hypertension were defined on the basis of percentiles from the average of 3 blood pressure measures taken on a single occasion. Percentiles for BMI and blood pressure were calculated by using the 2000 Centers for Disease Control and Prevention growth charts. Multinomial logistic regression was used to evaluate the odds for prehypertension and hypertension resulting from overweight and obesity.

RESULTS

Of 675 children (98.7% white), 122 (18.1%) were overweight and 77 (11.4%) were obese. Prehypertension and hypertension were detected in 51 (7.6%) and 50 (7.4%), respectively. After adjustment for family history of hypertension and kidney disease, obesity was associated with both prehypertension and hypertension. Overweight was associated with hypertension but not prehypertension. These associations were observed across the genders and children aged <13 and >or=13 years, except that overweight was not associated with hypertension among girls.

CONCLUSIONS

In this population of children who lived in a rural community in Canada, overweight and obesity were strongly associated with elevated blood pressure. Whether blood pressure normalizes with improvements in diet, physical activity, and environment is an area for additional study.

Moving forward by looking back: lessons learned from long-lost lifestyles

The paper briefly reviews the status and trends in physical activity, physical inactivity, and overweight/obesity in Canada; discusses the consequences of these trends; examines evidence that our frame of reference with respect to physical activity and obesity is changing; promotes the importance of getting “back to the basics” as a strategy for enhancing childhood physical activity; and provides suggestions for future research in this area. In addressing these topics, the paper explores and contrasts the lifestyles and characteristics of Old Order Amish and Old Order Mennonite children with children exposed to contemporary modern living. This exploration is used as a model to learn from traditional lifestyles, which were comparatively active and resistant to obesity. The fitness characteristics and physical activity levels of traditional and contemporary groups are compared and demonstrate significant differences among groups. This evidence may provide important insight for informing future physical activity recommendations. Idiosyncrasies of performing research on these traditional-living groups are also provided.

Physical activity of Canadian and American children: a focus on youth in Amish, Mennonite, and modern cultures

Childhood obesity is an urgent public health problem in North America and throughout most of the industrialized world. Diminishing levels of physical activity and the growth of sedentary pursuits may be contributing to the obesity epidemic. The advent of modern technological societies has brought about dramatic changes in lifestyle over the past century. To gain insights into physical activity levels in pre-industrial era societies, researchers have turned to studying religious groups that have resisted the lure of technological change. Children in Old Order Amish and Old Order Mennonite communities of North America have a lifestyle that still involves walking to school and friends' homes, performing chores, caring for farm animals, and active play. Research has shown that Amish and Mennonite children have higher levels of physical activity than modern-living children, despite less participation in organized competitive sports. As a result, Amish and Mennonite children tend to be leaner than their counterparts in contemporary society. Studying non-mainstream cultures can provide a valuable perspective on human behaviors.

Secular trends of pedometer-determined physical activity in Swedish school children

AIM

To explore the secular trends (time change) of pedometer-determined physical activity (steps per day) in Swedish schoolchildren 7-9 years of age from 2000 to 2006. It was an additional aim to examine the secular trends in body mass index.

METHODS

The study was analyzed between two cross-sectional cohorts on children 7-9 years of age carried out in October 2000 (336 children, 153 girls) and March/April 2006 (168 children, 83 girls) in the same five schools in south eastern Sweden, using identical procedures at the two occasions. Data of mean steps per day were collected during four consecutive weekdays (sealed pedometer Yamax SW-200 Tokyo, Japan) and in addition height and weight were measured.

RESULTS

Physical activity (mean steps per day) was significantly higher in 2006 than in 2000 among girls (13,788 vs. 15,141 steps per day) and boys (15,991 vs. 16,973 steps per day). The share of girls and boys to meet the preliminary weight control recommendations of 12,000 and 15,000 steps per day respectively was higher in 2006 than in 2000: 90% versus 75% (girls) and 67% versus 60% (boys).

CONCLUSION

The level of physical activity (steps per day) during school weekdays was higher in 2006 than in 2000. Enhanced focus on physical activity in society and at school might have influenced the result.

Le mouvement secondaire, l’activité intégrée aux habitudes de vie et le sommeil : les nouvelles frontières de l’évaluation de l’activité physiqueCet article est tiré d’un supplément intitulé Advancing physical activity measurement and guidelines in Canada: a scientific review and evidence-based foundation for the future of Canadian physical activity guidelines (Favoriser les lignes directrices et la mesure de l’activité physique au Canada: examen scientifique et justification selon les données probantes pour l’avenir des lignes directrices de l’activité physique canadienne) publié par Physiologie appliquée, nutrition et métabolisme et la Revue canadienne de santé publique. On peut aussi mentionner Appl. Physiol. Nutr. Metab. 32 (Suppl. 2F) ou Can. J. Public Health 98 (Suppl. 2)

Les messages de santé publique en matière d’activité physique au Canada ont mis traditionnellement l’accent sur la prescription d’exercices physiques utiles, principalement pratiqués durant les périodes de loisir (LTPA). Même si les LTPA contribuent à la dépense énergétique totale (TEE), une grande partie des activités faites durant la journée sont négligées à moins de porter une attention à l’énergie dépensée en plus des activités utiles. Cet article analyse l’impact des activités physiques dites accessoires (ne constituant pas de l’exercice physique en soi ou n’étant pas utiles) et des activités physiques intégrées dans le mode de vie (les tâches journalières et la marche concomitante) sur la TEE et les indicateurs de santé. Comme les mouvements accessoires s’accomplissent de façon intermittente dans le quotidien, cette forme de dépense d’énergie devrait diminuer face à la généralisation de la mécanisation et de l’automatisation des tâches. Cet article analyse aussi la relation entre l’inactivité physique, y compris le sommeil, et l’activité physique, la TEE et les répercussions sur la santé. On y trouve également des propositions visant à la prescription d’activité physique plus détaillée incluant toutes les composantes de la TEE. Le monitorage objectif des activités physiques selon les périodes de la journée constitue le meilleur moyen d’évaluer et d’analyser les mouvements humains durant toute la journée.

Incidental movement, lifestyle-embedded activity and sleep: new frontiers in physical activity assessmentThis article is part of a supplement entitled Advancing physical activity measurement and guidelines in Canada: a scientific review and evidence-based foundation for the future of Canadian physical activity guidelines co-published by Applied Physiology, Nutrition, and Metabolism and the Canadian Journal of Public Health. It may be cited as Appl. Physiol. Nutr. Metab. 32(Suppl. 2E) or as Can. J. Public Health 98(Suppl. 2)

Canadian public health messages relating to physical activity have historically focused on the prescription of purposeful exercise, most often assessing leisure-time physical activity (LTPA). Although LTPA contributes to total energy expenditure (TEE), a large part of the day remains neglected unless one also considers the energy expended outside of purposeful exercise. This paper reviews the potential impact of incidental (non-exercise or non-purposeful) physical activity and lifestyle-embedded activities (chores and incidental walking) upon TEE and indicators of health. Given that incidental movement occurs sporadically throughout the day, this form of energy expenditure is perhaps most vulnerable to increasingly ubiquitous mechanization and automation. The paper also explores the relationship of physical inactivity, including sleep, to physical activity, TEE, and health outcomes. Suggestions are provided for a more comprehensive physical activity recommendation that includes all components of TEE. Objective physical activity monitors with time stamps are considered as a better means to capture and examine human movements over the entire day.