Recomendaciones para la evaluación de la actividad física en población infantil

El propósito de este artículo fue el de revisar los patrones de movimiento de los niños y las niñas y como estos pueden impactar la evaluación de la actividad física. Para el logro de la evaluación de esta se requiere de instrumentos que sean sensibles para que se detecte, codifique o registre la actividad física esporádica e intermitente de los niños y las niñas, sin olvidar las regulaciones que existen en el nivel científico. Varios de los instrumentos de más uso son: el autorreporte, la observación directa y el monitoreo de la frecuencia cardiaca. Los autorreportes requieren de habilidades de pensamiento abstracto y de buena memoria, lo que en edades tempranas no se ha desarrollado, por otro lado, la observación directa y el monitorio cardiaco, requieren de gran cantidad de tiempo y de alta tecnología para su aplicación, respectivamente. La recomendación más ampliamente extendida, es que se recurra a una combinación instrumentos, para garantizar la mayor cantidad de información y de validez de la investigación.

Physical Activity and Bone Mineral Accrual During Childhood and Adolescence

The epidemic that is osteoporosis has led to an increasing interest in bone mineral, and the factors that influence the levels of bone mineral, in recent years. While it is unrealistic to try and turn back the clock, a return to an increased level of physical activity may be an important consideration in terms of skeletal health. Peak bone mass is largely determined by heredity, but lifestyle and dietary patterns also influence the level of bone mineral accrued during the growing years. In this review, we summarize the evidence that vigorous weight-bearing physical activity and adequate calcium intake represent the best possibility for enhancing the attainment of an optimal level of bone mineral, within genetic limits.

Influence of physical activity and dietary habits on lipid profile, blood pressure and BMI in subjects with metabolic syndrome

BACKGROUND The present study was determined the influence of physical activity and dietary habits on lipid profile, blood pressure (BP) and body mass index (BMI) in subjects with metabolic syndrome (MS). AIMS Identify the relationship between physical activity and proper nutrition and the probability of suffering from myocardial infarction (MI). METHODS Hundred chronically ill with MS who were active and followed a healthy diet were classified as compliant, while the remaining subjects were classified as non-compliant. RESULTS The compliant subjects show lower BMI values (30.8±4.9 vs 32.5±4.6), as well as lower levels of triacylglycerol (130.4±48.2 vs 242.1±90.1), total cholesterol (193.5±39 vs 220.2±52.3) and low-density lipoprotein cholesterol (105.2±38.3 vs 139.2±45). They show higher values in terms of high-density lipoprotein cholesterol levels (62.2±20.1 vs 36.6±15.3), with statistically significant differences. In terms of both systolic and diastolic pressure, no differences were revealed between the groups; however, those who maintain proper dietary habits show lower systolic blood pressure levels than the inactive subjects. The probability of suffering from MI greatly increases among the group of non-compliant subjects. CONCLUSIONS Our results demonstrate how performing aerobic physical activity and following an individualized, Mediterranean diet significantly reduces MS indicators and the chances of suffering from MI.

Objectively measured physical activity and sedentary time in youth: the International children's accelerometry database (ICAD).

BACKGROUND: Physical activity and sedentary behaviour in youth have been reported to vary by sex, age, weight status and country. However, supporting data are often self-reported and/or do not encompass a wide range of ages or geographical locations. This study aimed to describe objectively-measured physical activity and sedentary time patterns in youth. METHODS: The International Children's Accelerometry Database (ICAD) consists of ActiGraph accelerometer data from 20 studies in ten countries, processed using common data reduction procedures. Analyses were conducted on 27,637 participants (2.8-18.4 years) who provided at least three days of valid accelerometer data. Linear regression was used to examine associations between age, sex, weight status, country and physical activity outcomes. RESULTS: Boys were less sedentary and more active than girls at all ages. After 5 years of age there was an average cross-sectional decrease of 4.2 % in total physical activity with each additional year of age, due mainly to lower levels of light-intensity physical activity and greater time spent sedentary. Physical activity did not differ by weight status in the youngest children, but from age seven onwards, overweight/obese participants were less active than their normal weight counterparts. Physical activity varied between samples from different countries, with a 15-20 % difference between the highest and lowest countries at age 9-10 and a 26-28 % difference at age 12-13. CONCLUSIONS: Physical activity differed between samples from different countries, but the associations between demographic characteristics and physical activity were consistently observed. Further research is needed to explore environmental and sociocultural explanations for these differences.

Lack of association between PCK1 polymorphisms and obesity, physical activity, and fitness in European Youth Heart Study (EYHS)

Phosphoenolpyruvate carboxykinase-1 (PCK1) is the rate-limiting enzyme in the hepatic gluconeogenic pathway. Studies have shown that overexpression of Pck1 in mice results in obesity-related traits and higher levels of physical activity (PA). Therefore, our aims were to investigate whether common genetic variation in the PCK1 gene influences obesity-related traits, PA, and fitness, and to examine whether PA and fitness attenuate the influence of the PCK1 polymorphisms on obesity in children. Analyses were undertaken on data from Danish and Estonian children (958 boys and 1,104 girls) from the European Youth Heart Study (EYHS), a school-based, cross-sectional study of children (mean ± s.d. age: 9.6 ± 0.4 years) and adolescents (15.5 ± 0.5 years). We genotyped eight polymorphisms that captured the common genetic variations in the PCK1 gene. The association between the PCK1 polymorphisms and BMI, waist circumference (WC), sum of four skinfolds, PA, and fitness was tested using an additive model adjusted for age, age-group, gender, maturity, and country. Interactions were tested by including interaction terms in the model. None of the polymorphisms were significantly associated with BMI, WC, sum of four skinfolds, PA, and fitness, and also with the risk of being overweight or obese (P > 0.05). The interactions between the polymorphisms and age-group, gender, PA, and fitness were not statistically significant. This is the first study to comprehensively examine the association of PCK1 polymorphisms with obesity, PA, and fitness. Despite strong evidence from animal studies, our study in the EYHS cohort failed to identify an association of PCK1 polymorphisms with obesity, PA, and fitness.

A study of the relationship between physical activity and cardiovascular fitness and coronary heart disease risk factors in female adolescents

The association of measures of physical activity with coronary heart disease (CHD) risk factors in children, especially those for atherosclerosis, is unknown. The purpose of this study was to determine the association of physical activity and cardiovascular fitness with blood lipids and lipoproteins in pre-adolescent and adolescent girls.^ The study population was comprised of 131 girls aged 9 to 16 years who participated in the Children's Nutrition Research Center's Adolescent Study. The dependent variables, blood lipids and lipoproteins, were measured by standard techniques. The independent variables were physical activity measured as the difference between total energy expenditure (TEE) and basal metabolic rate (BMR), and cardiovascular fitness, VO$\rm\sb{2max}$(ml/min/kg). TEE was measured by the doubly-labeled water (DLW) method, and BMR by whole-room calorimetry. Cardiovascular fitness, VO$\rm\sb{2max}$(ml/min/kg), was measured on a motorized treadmill. The potential confounding variables were sexual maturation (Tanner breast stage), ethnic group, body fat percent, and dietary variables. A systematic strategy for data analysis was used to isolate the effects of physical activity and cardiovascular fitness on blood lipids, beginning with assessment of confounding and interaction. Next, from regression models predicting each blood lipid and controlling for covariables, hypotheses were evaluated by the direction and value of the coefficients for physical activity and cardiovascular fitness.^ The main result was that cardiovascular fitness appeared to be more strongly associated with blood lipids than physical activity. An interaction between cardiovascular fitness and sexual maturation indicated that the effect of cardiovascular fitness on most blood lipids was dependent on the stage of sexual maturation.^ A difference of 760 kcal/d physical activity (which represents the difference between the 25th and 75th percentile of physical activity) was associated with negligible differences in blood lipids. In contrast, a difference in 10 ml/min/kg of VO$\rm\sb{2max}$ or cardiovascular fitness (which represents the difference between the 25th and 75th percentile in cardiovascular fitness) in the early stages of sexual maturation was associated with an average positive difference of 15 mg/100 ml ApoA-1 and 10 mg/100 ml HDL-C. ^

Physical activity and survival after a first myocardial infarction: The Corpus Christi Heart Project

Previous studies have demonstrated that habitual physical activity is associated with a reduced risk of incident coronary heart disease (CHD). However, the role of physical activity in lowering the risk of all-cause mortality, CHD mortality, reinfarction, or receipt of a revascularization procedure after a first myocardial infarction (MI) remains unresolved, particularly in minority populations. To investigate the associations between physical activity and risk of all-cause mortality, CHD mortality, reinfarction, and receipt of a revascularization procedure, this study was conducted among Mexican-American and non-Hispanic white women and men who survived a first MI. The Corpus Christi Heart Project, a population-based cardiovascular surveillance study, provide data which included vital status, survival time, medical history, CHD risk factor information, including level of physical activity among Mexican-American and non-Hispanic white adults who had experienced a first MI between May, 1988 and April, 1990. MI patients were interviewed at baseline and annually thereafter until their death or through May, 1995. A categorical variable was created to reflect change in level of physical activity following the first MI; categories included (1) sedentary with no change, (2) decreased activity, (3) increased activity, and (4) moderate activity with no change (the referent group). Proportional hazards regression analyses were used to assess the relationship of level of physical activity and risk of death, reinfarction, or receipt of a revascularization procedure adjusting for age, sex, ethnicity, severity of MI, and CHD risk factor status. Over a 7-year follow-up period, the relative risk (95% confidence intervals) of all-cause mortality was 4.67 (2.27, 9.60) for the sedentary-no change group, 2.33 (0.96, 5.67) for the decreased activity group, and 0.52 (0.11, 2.41) for the increased activity group. The relative risk of CHD mortality was 6.92 (2.05, 23.34) for the sedentary-no change group, 2.40 (0.55, 10.51) for the decreased activity group, and 1.58 (0.26, 9.65) for the increased activity group. The relative risk for reinfarction was 2.50 (1.52, 4.10) for the sedentary-no change group, 2.26 (1.24, 4.12) for the decreased activity group, and 0.52 (0.21, 1.32) for the increased activity group. Finally, the relative risk for receipt of a revascularization procedure was 0.65 (0.39, 1.07) for the sedentary-no change group, 0.45 (0.22, 0.92) for the decreased activity group, and 1.01 (0.51, 2.02) for the increased activity group. No interactions were observed for ethnicity or severity of first MI. These results are consistent with the hypothesis that moderate physical activity is independently associated with a lower risk of all-cause mortality, CHD mortality, and reinfarction, but not revascularization, among Mexican-American and non-Hispanic white, female and male, first MI patients. These results also support the current recommendation that physical activity plays an important role in the secondary prevention of CHD. ^

Association of self-reported physical activity and performance in the physical fitness assessment among Airmen

The U.S. Air Force, as with the other branches of military services, has physical fitness standards imposed on their personnel. These standards ensure a healthy and fit combat force. To meet these standards, Airmen have to maintain a certain level of physical activity in their lifestyle. Objective. This was a cross sectional (prevalence) study to evaluate the association of Airmen's self-reported physical activity and their performance in the Air Force Physical Fitness Assessment in 2007. Methods. The self-reported physical activity data were obtained from the Air Force Web Health Assessment (AF WEB HA), a web-based health questionnaire completed by the Airmen during their annual Preventive Health Assessment. The physical activity levels were categorized as having met or not having met the Centers for Disease Control and Prevention (CDC) and the American College of Sports Medicine (ACSM) physical activity recommendations. Physical Fitness scores were collected from the Air Force Fitness Management System (AFFMS), a repository of physical fitness test data. Results. There were 49,029 Airmen who answered the AF WEB HA in 2007 and also took their physical fitness test. 94.4% (n = 46,304) of Airmen met the recommended physical activity guidelines and 79.9% (n = 39,178) passed the fitness test. Total Airmen who both met the physical activity recommendations and passed the fitness test was 75.6% (n = 37,088). Airmen who did not meet the activity recommendations and also failed the fitness test totaled 635 or 1.3% of the study group. The Mantel-Haenszel Chi-Square analysis of the data on the activity levels and the physical fitness test relationship was the following χ2 = 18.52, df 1, and p = <0.0001. The Odds Ratio (OR) was 1.22 (95% CI 1.12, 1.34). Conclusion. The study determined that there was a positive association between Airmen's self-reported physical activity and their performance in the physical fitness assessment.^

Self-affirmation promotes physical activity

The present study tests whether a self-affirmation intervention (i.e., requiring an individual to focus on a valued aspect of their self-concept, such as honesty) can increase physical activity and change theory of planned behavior (TPB) variables linked to physical activity. Eighty young people completed a longitudinal intervention study. Baseline physical activity was assessed using the Godin Leisure-Time Physical Activity Questionnaire (LTPAQ). Next, participants were randomly allocated to either a self-affirmation or a nonaffirmation condition. Participants then read information about physical activity and health, and completed measures of TPB variables. One week later, participants again completed LTPAQ and TPB items. At follow up, self-affirmed participants reported significantly more physical activity, more positive attitudes toward physical activity, and higher intentions to be physically active compared with nonaffirmed participants. Neither attitudes nor intentions mediated the effects of self-affirmation on physical activity. Self-affirmation can increase levels of physical activity and TPB variables. Self-affirmation interventions have the potential to become relatively simple methods for increasing physical activity levels. © 2014 Human Kinetics, Inc.

Randomized, controlled trial promotes physical activity and reduces consumption of sweets and sodium among overweight and obese adults

The present study sought to assess the impact of an intervention to reduce weight and control risk factors of noncommunicable chronic diseases in overweight or obese adults who are users of primary and secondary healthcare units of the public health system of Pelotas, Brazil. We hypothesized that individuals who received an educational intervention regarding how to lose weight and prevent other noncommunicable chronic disease risk factors through nutrition would lose weight and acquire active habits during leisure time more frequently than individuals under regular care. Two hundred forty-one participants from the Nutrition Outpatient Clinic of the Medical Teaching Hospital of the Federal University of Pelotas, Brazil, aged 20 years or older and classified as overweight or obese were randomly allocated to either the intervention group (IG; n = 120) or control group (CG; n = 121). The IG received individualized nutritional care for 6 months, and the CG received individualized usual care of the health services. Intention-to-treat analyses showed that at 6 months, mean fasting glycemia and daily consumption of sweet foods and sodium were reduced, and the time spent on physical leisure activity was increased in IG. Analysis of adherence to the protocol of the study revealed that individuals from IG had lost more in body weight, waist circumference, and fasting glucose compared to the CG. Leisure time physical activity increased in IG. Individuals adhered equally to the dietetic recommendations, irrespective of the nutrition approach that was used