Muscular Fitness and Cardiometabolic Variables in Children and Adolescents: A Systematic Review.

BACKGROUND: The importance of muscular fitness (MF) in the performance of activities of daily living is unequivocal. Additionally, emerging evidence has shown MF can reduce cardiometabolic risk in children and adolescents. OBJECTIVES: The purpose of this study was to examine and summarize the evidence regarding the relationship between MF phenotypes (i.e., maximum muscular strength/power, muscular endurance, and maximum muscular strength/power/endurance) and cardiometabolic variables (obesity, blood pressure, lipids, glucose homeostasis, inflammatory markers, and clustered cardiometabolic variables) in children and adolescents. DESIGN: This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and was registered with PROSPERO, number CRD42020179273. DATA SOURCES: A systematic review was performed on five databases (PubMed, EMBASE, SciELO, Scopus, and Web of Knowledge) from database inception to May 2020, with complementary searches in reference lists. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Eligibility criteria included (1) a study sample of youth aged ≤ 19 years, (2) an assessment of MF with individual or clustered cardiometabolic variables derived from adjusted models (regardless of test/measurement adopted or direction of reported association), and (3) a report of the association between both, using observational studies. Only original articles published in peer-reviewed journals in English, Portuguese, and Spanish languages were considered. The quality of the included studies was assessed by using the National Heart, Lung, and Blood Institute checklist. The percentage of results reporting a statistically significant inverse association between each MF phenotype and cardiometabolic variables was calculated. RESULTS: Of the 23,686 articles initially identified, 96 were included (77 cross-sectional and 19 longitudinal), with data from children and adolescents from 35 countries. The score for the quality of evidence ranged from 0.33 to 0.92 (1.00 maximum). MF assessed by maximum muscular strength/power was inversely associated with lower obesity (64/113 total results (56.6%)) and reduction in clustered cardiometabolic risk (28/48 total results (58.3%)). When assessed by muscular endurance, an inverse association with obesity (30/44 total results (68.1%)) and cardiometabolic risk (5/8 total results (62.5%)) was identified. Most of the results for the relationship between MF phenotypes with blood pressure, lipids, glucose homeostasis, and inflammatory markers indicated a paucity of evidence for these interrelationships (percentage of results below 50.0%). CONCLUSION: MF assessed by maximum muscular strength/power or muscular endurance is potentially associated with lower obesity and lower risk related to clustered cardiometabolic variables in children and adolescents. There is limited support for an inverse association between MF with blood pressure, lipids, glucose homeostasis biomarkers, and inflammatory markers in children and adolescents.

Physical inactivity as a risk factor for all-cause mortality in Brazil (1990-2017).

BACKGROUND: The aim of this study was to estimate the mortality from all causes as a result of physical inactivity in Brazil and in Brazilian states over 28 years (1990-2017). METHODS: Data from the Global Burden of Disease (GBD) study for Brazil and states were used. The metrics used were the summary exposure value (SEV), the number of deaths, age-standardized mortality rates, and the fraction of population risk attributable to physical inactivity. RESULTS: The Brazilian population presented risk of exposure to physical inactivity of (age-standardized SEV) of 59% (95% U.I. 22-97) in 1990 and 59% in 2017 (95% U.I. 25-99). Physical inactivity contributed a significant number of deaths (1990, 22,537, 95% U.I. 12,157-34,745; 2017, 32,410, 95% U.I. 17,976-49,657) in the analyzed period. These values represented mortality rates standardized by age (per 100,000 inhabitants) of 31 (95% U.I. 17-48) in 1990 and 15 (95% U.I. 8-23) in 2017. From 1990 to 2017, a decrease in standardized death rate from all causes attributable to physical inactivity was observed in Brazil (- 52%, 95% U.I. - 54 to - 49). The Brazilian states with better socioeconomic conditions presented greater reductions in age-standardized mortality (male: rho = 0.80; female: rho 0.84) over the period of 28 years. CONCLUSIONS: These findings support the promotion of physical activity in the Brazilian population for the prevention of early mortality.

Mortality and years of life lost due to breast cancer attributable to physical inactivity in the Brazilian female population (1990-2015).

The aims of this study were as follows: to estimate the mortality and years of life lost, assessed by disability-adjusted life years (DALYs), due to breast cancer attributable to physical inactivity in Brazilian women; to compare the estimates attributable to physical inactivity and to other modifiable risk factors; and to analyse the temporal evolution of these estimates within Brazilian states over 25 years (1990-2015), compared with global estimates. Databases from the Global Burden of Disease Study for Brazil, Brazilian states, and other parts of the world were used. Physical inactivity has contributed to a substantial number of deaths (1990: 875; 2015: 2,075) and DALYs (1990: 28,089; 2015: 60,585) due to breast cancer in Brazil. Physical inactivity was responsible for more deaths and DALYs (~12.0%) due to breast cancer than other modifiable risk factors (~5.0%). The Brazilian states with better socioeconomic indicators had higher age-standardized rates of mortality and morbidity due to breast cancer attributable to physical inactivity. From 1990 to 2015, mortality due to breast cancer attributable to physical inactivity increased in Brazil (0.77%; 95%U.I.: 0.27-1.47) and decreased (-2.84%; 95%U.I.: -4.35 - -0.10) around the world. These findings support the promotion of physical activity in the Brazilian female population to prevent and manage breast cancer.

Association between Resting Heart Rate and Health-Related Physical Fitness in Brazilian Adolescents.

The aim of this study was to identify the relationship between health-related physical fitness components (aerobic fitness, muscle strength, flexibility, and body fat) and resting heart rate (RHR) in Brazilian adolescents. The study included 695 schoolchildren (14-19 years) from public schools of the city of São José, Brazil. RHR was evaluated using an automated oscillometric sphygmomanometer. Aerobic fitness was assessed by the modified Canadian Aerobic Fitness Test; muscle strength was measured by handgrip dynamometer; flexibility was assessed by the sit-and-reach test; and body fat was assessed indirectly by sum of two skinfold thicknesses (triceps and subscapular). Sociodemographic variables, habitual physical activity, sexual maturation, and body mass index were the covariates. Cardiorespiratory fitness (ß = -0.11; 95%CI: -0.14, -0.08) and handgrip strength (ß = -0.10; 95%CI: -0.18, -0.01) were inversely associated with RHR in boys. For girls, cardiorespiratory fitness (ß = -0.09; 95%CI: -0.12, -0.06) was inversely associated with RHR. In both sexes, body fat (ß = 0.50; 95%CI: 0.25, 0.75 for boys; ß = 0.17; 95%CI: 0.36, 2.72 for girls) was directly associated with RHR. The RHR is measured more easily than the physical fitness tests, so it is recommended to assess adolescent's heath in large surveillance systems.

Mortality and years of life lost by colorectal cancer attributable to physical inactivity in Brazil (1990-2015): Findings from the Global Burden of Disease Study.

INTRODUCTION: The aims of this study were to estimate all-cause and cause-specific mortality and years of life lost, investigated by disability-adjusted life-years (DALYs), due to colorectal cancer attributable to physical inactivity in Brazil and in the states; to analyze the temporal trend of these estimates over 25 years (1990-2015) compared with global estimates and according to the socioeconomic status of states of Brazil. METHODS: Databases from the Global Burden of Disease Study (GBD) for Brazil, Brazilian states and global information were used. It was estimated the total number and the age-standardized rates of deaths and DALYs for colorectal cancer attributable to physical inactivity in the years 1990 and 2015. We used the Socioeconomic Development Index (SDI). RESULTS: Physical inactivity was responsible for a substantial number of deaths (1990: 1,302; 2015: 119,351) and DALYs (1990: 31,121; 2015: 87,116) due to colorectal cancer in Brazil. From 1990 to 2015, the mortality and DALYs due to colorectal cancer attributable to physical inactivity increased in Brazil (0.6% and 0.6%, respectively) and decreased around the world (-0.8% and -1.1%, respectively). The Brazilian states with better socioeconomic indicators had higher rates of mortality and morbidity by colorectal cancer due to physical inactivity (p<0.01). Physical inactivity was responsible for deaths and DALYs due to colorectal cancer in Brazil. CONCLUSIONS: Over 25 years, the Brazilian population showed more worrisome results than around the world. Actions to combat physical inactivity and greater cancer screening and treatment are urgent in the Brazilian states.

Factor Structure of Responses to the Portuguese Version of Questions About Screen Time-Based Sedentary Behavior Among Adolescents.

BACKGROUND: This study aimed to examine the factor structure of responses to the Portuguese version of questions related to screen time-based sedentary behavior among adolescents. METHODS: This cross-sectional study with a sample of 1083 adolescents aged 14-19 years was conducted in Brazil. The sample was randomly divided into 2 groups for an exploratory factor analysis and for a confirmatory factor analysis. Screen time was investigated by a Portuguese version of questions about time sitting in front of television, computer, and video games on weekdays and weekends. RESULTS: Scree plots showed 2 factors with eigenvalues above 1. One factor was formed by items about television and computer use, and the other factor was formed by items about video game use. The exploratory factor analysis with 2 factors resulted in factor loadings above .60. A second model with 1 factor was estimated and resulted in factor loadings above .55. A confirmatory factor analysis was estimated based on the 2-factor exploratory factor analysis and goodness-of-fit statistics were adequate. Confirmatory factor analysis with 1 factor had goodness-of-fit statistics adequate. CONCLUSIONS: The Portuguese language version of self-report screen time had 2 possible factor solutions, and items demonstrated good factor structure with reasonable reliability making it suitable for use in the future studies.

Low aerobic fitness in Brazilian adolescents / Baixa aptidão aeróbia em adolescentes brasileiros / Bajos niveles de capacidad aeróbica en adolescentes de Brasil

INTRODUCTION: aerobic fitness is considered one of the most important components of health-related physical fitness, with low levels related to increased risk of premature death from all causes, especially cardiovascular diseases. OBJECTIVE: to identify the characteristics of adolescents at higher risk of low levels of aerobic fitness. METHODS: the study included 696 adolescents 15-17 years of age enrolled in public high schools of Florianópolis, southern Brazil. This cross-sectional epidemiological study was conducted in Florianópolis, Santa Catarina, Brazil. Aerobic fitness was measured using the modified Canadian Aerobic Fitness Test mCAFT. Sociodemographic gender, age, school grade, paternal and maternal schooling, socioeconomic status, and anthropometric variables body weight, height, triceps and subscapular skinfold thickness, sexual maturation, physical activity, sedentary behavior, and eating habits were collected. RESULTS: it was found that 31.5% of adolescents had low aerobic fitness levels, being higher in boys 49.2% compared to girls 20.6%. Moreover, girls with sedentary behavior, overweight and high body fat percentage were the groups most likely to have inadequate aerobic fitness. In males, the groups most likely to have inadequate aerobic fitness were those whose parents studied more than eight years, those with low levels of physical activity, and those with inadequate nutrition and excessive body fat. CONCLUSION: low aerobic fitness levels were present in one third of adolescents and was more prevalent in boys. Lifestyle changes, including replacement of sedentary behaviors by physical and sport activities , may assist in improving the aerobic fitness of Brazilian adolescents. .

INTRODUÇÃO: a aptidão aeróbia é considerada um dos componentes mais importantes da aptidão física relacionada com a saúde, pois seus baixos níveis estão relacionados com o maior risco de morte prematura por todas as causas, especialmente as doenças cardiovasculares. OBJETIVO: identificar as características dos adolescentes com maior risco de baixos níveis de aptidão aeróbia. MÉTODOS: participaram do estudo 696 adolescentes 15 a 17 anos matriculados no ensino médio de escolas públicas de Florianópolis, no sul do Brasil. Este estudo epidemiológico transversal foi realizado em Florianópolis, Santa Catarina, Brasil. A aptidão aeróbia foi medida com o Modified Canadian Aerobic Fitness Test mCAFT. Foram coletadas variáveis sociodemográficas sexo, idade, série de ensino escolar, escolaridade do pai e da mãe, nível econômico, antropométricas peso corporal, estatura, dobras cutâneas tricipital e subescapular, maturação sexual, atividade física, comportamento sedentário e hábitos alimentares. RESULTADOS: observou-se que 31,5% dos adolescentes apresentaram baixos níveis de aptidão aeróbia, sendo maior nos rapazes 49,2% com relação às moças 20,6%. Ademais, as moças com comportamento sedentário, excesso de peso e adiposidade corporal alta foram os grupos com maiores chances de inadequação na resistência aeróbia. No sexo masculino, os grupos com maiores chances de inadequação na aptidão aeróbia foram aqueles cujos pais estudaram mais de oito anos, os pouco ativos fisicamente e os que tinham alimentação inadequada e excesso de adiposidade corporal. CONCLUSÃO: os baixos níveis de aptidão aeróbia estavam presentes em um terço dos adolescentes, sendo mais prevalentes nos rapazes. As modificações no estilo de vida, com substituição dos hábitos sedentários pela prática de atividades físicas e esportivas podem ajudar a melhorar a aptidão aeróbia dos adolescentes brasileiros. .

INTRODUCCIÓN: la capacidad aeróbica es considerada uno de los más importantes componentes de la condición física relacionada con la salud, debido a que sus bajos niveles se asocian con un mayor riesgo de muerte prematura por todas las causas, especialmente la enfermedad cardiovascular. OBJETIVO: identificar las características de los adolescentes con mayor riesgo de bajos niveles de capacidad aeróbica. MÉTODOS: el estudio incluyó a 696 adolescentes 15-17 años matriculados en la educación secundaria en escuelas públicas en Florianópolis, en el sur de Brasil. Este estudio epidemiológico transversal se realizó en Florianópolis, Santa Catarina, Brasil. La condición física aeróbica se midió con el Modified Canadian Aerobic Fitness Test mCAFT. Fueron recogidas las variables sociodemográficas género, edad, serie de la educación escolar, escolaridad del padre y de la madre, nivel socioeconómico, antropométricas peso, altura, pliegue tricipital y subescapular, la maduración sexual, actividad física, el comportamiento sedentario y los hábitos alimentarios. RESULTADOS: se observó que el 31,5% de los adolescentes tenía bajos niveles de condición física aeróbica, siendo mayor en los varones 49,2% en comparación con las mujeres 20,6%. Además, las mujeres jóvenes con comportamiento sedentario, sobrepeso y grasa corporal alto fueron los grupos más propensos a ser insuficiente en la resistencia aeróbica. En los hombres, los grupos más propensos a ser insuficiente en la capacidad aeróbica fueron aquellos cuyos padres tenían más de ocho años de estudio, los que tenían poca actividad física y los que tenían alimentación inadecuada y exceso de grasa corporal. CONCLUSIÓN: los bajos niveles de capacidad aeróbica estaban presentes un tercio de los adolescentes, siendo más frecuente en los varones. Los cambios en el estilo de vida, con la sustitución de los hábitos sedentarios por la práctica de actividades físicas y deportivas pueden ayudar a mejorar la capacidad ...

Validity of SC-StepRx pedometer-derived moderate and vigorous physical activity during treadmill walking and running in a heterogeneous sample of children and youth.

BACKGROUND: The purpose of this study was to determine the validity of the SC-StepRx pedometer to assess moderate and vigorous physical activity during treadmill walking and running in a heterogeneous sample of children and youth aged 10-17 years. METHODS: Physical activity intensity assessed via indirect calorimetry served as the criterion standard. A convenience sample of 40 participants (20 boys, 20 girls) wore 6 SC-StepRx pedometers, 2 ActiGraph GT3X accelerometers, 2 Actical accelerometers, 1 Walk4Life MVP pedometer and 1 NL-1000 pedometer while walking/running at speeds approximating 2, 3, 4, 6 and 7 METs. Associations between indirect calorimetry and each activity monitor were assessed using linear regression analyses in SAS 9.2. RESULTS: Estimates of moderate and vigorous physical activity from all monitors were significantly associated with the criterion standard of indirect calorimetry. The strongest associations with the criterion measure were observed for the SC-StepRx with moderate/vigorous thresholds of 110/130 steps•minute(-1), and the NL-1000 (R2 = 0.82, p <0.05). The SC-StepRx with moderate/vigorous thresholds of 110/130 steps•minute(-1) also exhibited the highest combined sensitivity (92.9%) and specificity (96.5%) for correctly identifying a bout of moderate-to-vigorous physical activity. CONCLUSIONS: This study demonstrates that the SC-StepRx pedometer is a valid tool for the measurement of moderate and vigorous physical activity in children and youth.

Television time among Brazilian adolescents: correlated factors are different between boys and girls.

OBJECTIVE: The aim of this study was to identify the prevalence of excess television time and verify correlated factors in adolescent males and females. METHODS: This cross-sectional study included 2,105 adolescents aged from 13 to 18 years from the city of Aracaju, Northeastern Brazil. Television time was self-reported, corresponding to the time spent watching television in a typical week. Several correlates were examined including age, skin color, socioeconomic status, parent education, physical activity level, consumption of fruits and vegetables, smoking status, alcohol use, and sports team participation. RESULTS: The prevalence excess television time (≥ 2 hours/day) in girls and boys was 70.9% and 66.2%, respectively. Girls with low socioeconomic status or inadequate consumption of fruits and vegetables were more likely to have excess television time. Among boys, those >16 years of age or with black skin color were more likely to have excess television time. CONCLUSIONS: Excess television time was observed in more than two-thirds of adolescents, being more evident in girls. Correlated factors differed according to sex. Efforts to reduce television time among Brazilian adolescents, and replace with more active pursuits, may yield desirable public health benefits.

Physical fitness, motor skill, and physical activity relationships in grade 4 to 6 children.

The present study sought to quantify the relationships among physical activity (PA), health-related fitness, and motor skill in children (grades 4 to 6), and to determine whether specific tests of fitness or motor skill are independently associated with objectively measured PA level. Four hundred and ninety-one students (56.4% female) wore a Digi-Walker pedometer for 7 consecutive days. Standardized protocols were used to assess health-related fitness (body mass index percentile, waist circumference, 20-m shuttle run, plank, handgrip, and trunk flexibility). Motor skill was evaluated using a validated obstacle course. Pearson correlations (with Holm adjustments for multiple comparisons) initially assessed associations among PA, health-related fitness, and motor skill. Multi-variable linear regression was used to determine which factors were significantly associated with daily step counts, while adjusting for gender, age, testing season, and socioeconomic status. Step counts were significantly correlated with predicted aerobic power (r = 0.30), obstacle course time (r = -0.27), obstacle course score (r = 0.20), plank isometric torso endurance (r = 0.16), and handgrip strength (r = 0.12), but not with waist circumference (r = -0.10), trunk flexibility (r = 0.10), or overweight status (ρ = -0.06). In the multi-variable model, predicted aerobic power, obstacle course time, testing season, gender, and the predicted aerobic power by gender interaction were significantly associated with step counts, explaining 16.4% of the variance. Specifically, the relationship between predicted aerobic power and step counts was stronger in girls. These findings suggest that aerobic fitness and motor skill are independently associated with children's PA. Future longitudinal studies should evaluate whether interventions to enhance aerobic fitness and motor skill could enhance daily PA among children of this age.

Associations of sedentary behavior, sedentary bouts and breaks in sedentary time with cardiometabolic risk in children with a family history of obesity.

BACKGROUND: Although reports in adults suggest that breaks in sedentary time are associated with reduced cardiometabolic risk, these findings have yet to be replicated in children. PURPOSE: To investigate whether objectively measured sedentary behavior, sedentary bouts or breaks in sedentary time are independently associated with cardiometabolic risk in a cohort of Canadian children aged 8-11 years with a family history of obesity. METHODS: Data from 286 boys and 236 girls living in Quebec, Canada, with at least one biological parent with obesity (QUALITY cohort) were collected from 2005-2008, and analyzed in 2013. Sedentary behavior, light and moderate-to-vigorous physical activity were measured over 7 days using accelerometry. Leisure time computer/video game use and TV viewing over the past 7 days were self-reported. Outcomes included waist circumference, body mass index Z-score, fasting insulin, fasting glucose, triglycerides, HDL-cholesterol, C-reactive protein and a continuous cardiometabolic risk score. RESULTS: After adjustment for confounders, breaks in sedentary time and the number of sedentary bouts lasting 1-4 minutes were associated with reduced cardiometabolic risk score and lower BMI Z-score in both sexes (all p<0.05). The number of sedentary bouts lasting 5-9 minutes was negatively associated with waist circumference in girls only, while the number of bouts lasting 10-14 minutes was positively associated with fasting glucose in girls, and with BMI Z-score in boys (all p<0.05). Leisure time computer/video game use was associated with increased cardiometabolic risk score and waist circumference in boys, while TV viewing was associated with increased cardiometabolic risk, waist circumference, and BMI Z-score in girls (all p<0.05). CONCLUSIONS: These results suggest that frequent interruptions in sedentary time are associated with a favourable cardiometabolic risk profile and highlight the deleterious relationship between screen time and cardiometabolic risk among children with a family history of obesity.

Combined associations between moderate to vigorous physical activity and sedentary behaviour with cardiometabolic risk factors in children.

The objective of this study was to examine the combined associations between time spent in moderate- to vigorous-intensity physical activity (MVPA) and time spent sedentary in relation to cardiometabolic risk factors in a cohort of Canadian children. A cross-sectional study was conducted on 536 white children aged 8-10 years with at least 1 obese biological parent. Time spent in MVPA and sedentary behaviour over 7 days was measured using accelerometry and participants were stratified by tertiles. Daily screen time over 7 days was also self-reported by the child. Outcomes included waist circumference, systolic and diastolic blood pressure, fasting triglycerides, high-density lipoprotein cholesterol, and glucose concentrations. Analyses of covariance comparing tertiles of sedentary time/MVPA showed that higher levels of MVPA were associated with lower waist circumference, fasting triglycerides and diastolic blood pressure, and higher high-density lipoprotein (HDL) cholesterol, irrespective of sedentary time. In linear regression, MVPA was inversely associated with waist circumference and diastolic blood pressure and positively associated with HDL cholesterol, independent of covariates including sedentary time. In contrast, sedentary time was positively associated with diastolic blood pressure but after adjustment for MVPA the association was no longer statistically significant. Self-reported screen time was positively associated with waist circumference and negatively associated with HDL cholesterol independent of covariates including MVPA. Overall, a high level of MVPA was associated with reduced cardiometabolic risk in this sample of children, regardless of their amount of sedentary behaviour. The type of sedentary behaviour (i.e., screen time) might be more important than overall sedentary time in relation to cardiometabolic risk.

Child obesity and fitness levels among Kenyan and Canadian children from urban and rural environments: a KIDS-CAN Research Alliance Study.

OBJECTIVE: This study was designed to gather anthropometric and fitness-related data on Kenyan children living in urban (UKEN) and rural (RKEN) environments and to compare them with previous data collected on Canadian children in order to examine the potential nutrition-physical activity transition. METHODS: Height, weight, waist circumference, triceps skinfolds were directly measured on rural (RKEN) and urban Kenyan (UKEN) children (n = 179, 9-13 years) and compared with existing data from Canadian children living in urban and rural environments (n = 274, 9-13 years). Aerobic fitness was measured using the 20 m shuttle run, flexibility using the sit-and-reach test and isometric handgrip strength was assessed. RESULTS: None of the RKEN children were overweight or obese (OWO). However, 6.8% of UKEN boys and 16.7% of girls were OWO. The RKEN children had lower BMI, waist circumference, and triceps skinfolds than all other groups (UKEN, and Canadian: p < 0.05). UKEN children were leaner than Canadian children (p < 0.05). Male and female RKEN children had higher running speeds, and aerobic fitness than UKEN children (p < 0.001). Isometric strength was not different between Kenyan groups and was not different from urban living Canadian children. UKEN children were the least flexible group, and girls were more flexible than boys in all groups. CONCLUSIONS: Urban Kenyan children appear to be showing signs of the nutrition-physical activity transition, as judged by the anthropometric similarities to contemporary living Canadian children. Further support is provided by examining the difference in prevalence of overweight/obesity among UKEN compared with their RKEN counterparts and their lower aerobic fitness level.

Physiological and health implications of a sedentary lifestyle.

Sedentary behaviour is associated with deleterious health outcomes, which differ from those that can be attributed to a lack of moderate to vigorous physical activity. This has led to the field of "sedentary physiology", which may be considered as separate and distinct from exercise physiology. This paper gives an overview of this emerging area of research and highlights the ways that it differs from traditional exercise physiology. Definitions of key terms associated with the field of sedentary physiology and a review of the self-report and objective methods for assessing sedentary behaviour are provided. Proposed mechanisms of sedentary physiology are examined, and how they differ from those linking physical activity and health are highlighted. Evidence relating to associations of sedentary behaviours with major health outcomes and the population prevalence and correlates of sedentary behaviours are reviewed. Recommendations for future research are proposed.