64 research outputs found

    Design and analysis of vortex generator for UMP HEV using CFD

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    This thesis is doing vortex generator model with new high to overcome unstable airflow problem in rear car parts. So, with addition vortex generator on rear parts of proton iswara type Hybrid Electrical Vehicle (HEY) will decrease instability air movement on rear car parts. Beside that, addition of vortex generator in rear roof of car is to decrease high pressure and zero velocity area. It is because to make stability of car.Design of vortex generator is done based on shape Proton Iswara vortex generator but only with different high. The vortex generator high is determined based on this study. In this study, 3 velocities (90,100 and 110 km/h) will analyze using cosmosfioworks. Each velocity of car model will analyze with and without vortex generator. Based on this study, addition of vortex generator on rear car able to decrease total area of high pressure and low or zero velocity. This can be seen with decreasing of airflow in the rear car. It is because the vortex generator can be reduce the turbulent boundary layer flow

    Changes in motor competence over four decades in 10 to 14-year-old Austrian boys

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    Background: Data on secular trends in motor competence in children and adolescents has been equivocal. While several studies have shown a decline in motor competence over the last several decades there is also research that showed no change or even an increase in motor competence in youth.Methods: Motor competence was assessed via 6 test items in 10- to 14-year-old Austrian boys in the years 1972, 1987 and 2015. At each measurement time participants performed 20m sprint, 800m run, sit ups, jump and reach, one-leg stand and stand and reach tests in the school gymnasium during regular school time. Data across measurement times was compared using weighted means across 5 age groups with pooled standard deviations.Results: Average performance on the 20m sprint, jump and reach test and one leg stand improved significantly (p<0.05) from 1972 to 2015 by 0.3 seconds, 3.9 cm and 3.5 seconds, respectively. Time for the 800m run increased significantly by 15% (p<0.01), indicating a decline in endurance. Flexibility, measured by the stand and reach test, also declined significantly (p=0.02) from 1972 to 2015. There was no significant difference in the number of sit ups performed at the 3 measurement times. Conclusion: Results of the present study do not show a general decline in motor competence in male middle-school students over the last 4 decades. Rather, secular trends differ by specific components contributing to overall motor competence with declines in flexibility and endurance but increases in power, speed and balance

    Association between 24-h movement guidelines and cardiometabolic health in Chilean adults

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    © The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.This study aimed to examine the association between meeting 24-h movement guidelines and cardiometabolic health in Chilean adults. We used cross-sectional data of 2618 adults from the Chilean National Health Survey 2016-2017. Meeting the 24-h movement guidelines was defined as ≥ 600 MET-min/week of physical activity; ≤ 8 h/day of sitting time; and 7 to 9 h/day of sleep duration. Cardiometabolic health indicators were body mass index, waist circumference, high triglycerides, high blood pressure, type 2 diabetes, metabolic syndrome, and risk of cardiovascular disease in a 10-year period. Meeting none out of three 24-h movement guidelines (vs all three) was associated with higher odds of overweight/obesity (OR 1.67; 95%CI 1.45 to 1.89), high waist circumference (1.65; 1.40 to 1.90), hypertension (2.88; 2.23 to 3.53), type 2 diabetes (1.60; 1.26 to 1.94), metabolic syndrome (1.97; 1.54 to 2.40) and risk of cardiovascular disease (1.50; 1.20, 1.80). Meeting one guideline (vs three) was associated with higher odds of five of out seven cardiometabolic indicators. Our study found that the composition of movement behaviors within a 24-h period may have important implications for cardiometabolic health.info:eu-repo/semantics/publishedVersio

    The Association Between Sedentary Behaviors During Weekdays and Weekend with Change in Body Composition in Young Adults

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    Background: High sedentary time has been considered an important chronic disease risk factor but there is only limited information on the association of specific sedentary behaviors on weekdays and weekend-days with body composition. The present study examines the prospective association of total sedentary time and specific sedentary behaviors during weekdays and the weekend with body composition in young adults. Methods: A total of 332 adults (50% male; 27.7 ±3.7 years) were followed over a period of 1 year. Time spent sedentary, excluding sleep (SED), and in physical activity (PA) during weekdays and weekend-days was objectively assessed every 3 months with a multisensor device over a period of at least 8 days. In addition, participants reported sitting time, TV time and non-work related time spent at the computer separately for weekdays and the weekend. Fat mass and fat free mass were assessed via dual x-ray absorptiometry and used to calculate percent body fat (%BF). Energy intake was estimated based on TDEE and change in body composition. Results: Cross-sectional analyses showed a significant correlation between SED and body composition (0.18 ≤ r ≤ 0.34). Associations between body weight and specific sedentary behaviors were less pronounced and significant during weekdays only (r ≤ 0.16). Nevertheless, decrease in SED during weekends, rather than during weekdays, was significantly associated with subsequent decrease in %BF (β = 0.06, p \u3c0.01). After adjusting for PA and energy intake, results for SED were no longer significant. Only the association between change in sitting time during weekends and subsequent %BF was independent from change in PA or energy intake (β%BF = 0.04, p = 0.01), while there was no significant association between TV or computer time and subsequent body composition. Conclusions: The stronger AIMS Public Health Volume 3, Issue 2, 375-388. prospective association between sedentary behavior during weekends with subsequent body composition emphasizes the importance of leisure time behavior in weight management

    The Association Between Sedentary Behaviors During Weekdays and Weekend with Change in Body Composition in Young Adults

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    Background: High sedentary time has been considered an important chronic disease risk factor but there is only limited information on the association of specific sedentary behaviors on weekdays and weekend-days with body composition. The present study examines the prospective association of total sedentary time and specific sedentary behaviors during weekdays and the weekend with body composition in young adults. Methods: A total of 332 adults (50% male; 27.7 ±3.7 years) were followed over a period of 1 year. Time spent sedentary, excluding sleep (SED), and in physical activity (PA) during weekdays and weekend-days was objectively assessed every 3 months with a multisensor device over a period of at least 8 days. In addition, participants reported sitting time, TV time and non-work related time spent at the computer separately for weekdays and the weekend. Fat mass and fat free mass were assessed via dual x-ray absorptiometry and used to calculate percent body fat (%BF). Energy intake was estimated based on TDEE and change in body composition. Results: Cross-sectional analyses showed a significant correlation between SED and body composition (0.18 ≤ r ≤ 0.34). Associations between body weight and specific sedentary behaviors were less pronounced and significant during weekdays only (r ≤ 0.16). Nevertheless, decrease in SED during weekends, rather than during weekdays, was significantly associated with subsequent decrease in %BF (β = 0.06, p \u3c0.01). After adjusting for PA and energy intake, results for SED were no longer significant. Only the association between change in sitting time during weekends and subsequent %BF was independent from change in PA or energy intake (β%BF = 0.04, p = 0.01), while there was no significant association between TV or computer time and subsequent body composition. Conclusions: The stronger AIMS Public Health Volume 3, Issue 2, 375-388. prospective association between sedentary behavior during weekends with subsequent body composition emphasizes the importance of leisure time behavior in weight management

    Physical fitness in Austrian elementary school children prior to and post-COVID-19

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    Background: With the emergence of the COVID-19 pandemic, many countries implemented policies that included movement restrictions, social distancing and school closures in order to control the spread of the virus. Even though these actions may have been necessary to save lives, there have been some unintended consequences that could affect future public health. Methods: The present study uses data from more than 24,500 Austrian elementary school children (51.2% male) that participated in a state-wide fitness evaluation program, which was initiated in the 2016/17 school year. In addition to body weight and height, data on cardiorespiratory endurance, muscular power, speed, agility, flexibility and object control were collected from three cohorts prior to the implementation of movement restrictions (school years: 2016/17, 2017/18, 2018/19) and one cohort in 2022, after the majority of COVID-19 policies had been lifted. Results: Body mass index percentiles were significantly higher in children post-COVID-19 (p < 0.01). Further, cardiorespiratory endurance, agility and flexibility were significantly lower post-COVID-19 compared to the years preceding movement restrictions (p ≤ 0.01), while absolute muscular strength was higher in the year 2022 (p < 0.01). Conclusion: Given the detrimental effects of COVID-19 policies on physical fitness in children, additional efforts are necessary that include versatile opportunities for physical activity and the promotion of physical fitness in order to modify the observed negative health trajectories and ensure future public health

    Parental Characteristics Have a Larger Effect on Children's Health Behaviour than Their Body Weight

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    Objective: Parents take an important role in a child's development, but there is currently limited information on parental correlates with children's health behaviour. The purpose of this study, therefore, was to examine whether parental characteristics, such as body weight, TV consumption and sport participation, affect children's body weight and health behaviour. Methods: To examine the effects of parental characteristics on children's body weight and health behaviour, baseline data of 1,118 elementary school children (7.6 ± 0.4 years) participating in a school-based intervention in southwest Germany was used. Children's height and weight were measured and parent as well as child behaviour was assessed via questionnaire. Results: BMI percentiles of children were positively associated with parental BMI (r = 0.2, p < 0.01). Further, high parental TV time increased the odds for high TV time in children (ORmother = 2.2, ORfather = 2.3) and parental club sport participation increased the odds for club sport participation in children (ORmother = 1.9, ORfather = 1.7). The relationship between parental and child behaviour was stronger than the relationship between parental BMI and BMI percentiles of the child. Conclusion: These results suggest that parental behaviour and role modelling provide an important contribution to childrens' health behaviour, especially at younger ages

    Examination of Athlete Triad Symptoms Among Endurance-Trained Male Athletes: A Field Study

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    Background: Studies examining the physiological consequences associated with deficits in energy availability (EA) for male athletes are sparse. Purpose: To examine male athlete triad components; low energy availability (LEA) with or without an eating disorder risk (ED), reproductive hormone [testosterone (T)], and bone mineral density (BMD) in endurance-trained male athletes during different training periods. Methods: A cross-sectional design with 14 participants (age: 26.4 ± 4.2 years; weight: 70.6 ± 6.4 kg; height: 179.5 ± 4.3 cm; BMI: 21.9 ± 1.8 kg/m2) were recruited from the local community. Two separate training weeks [low (LV) and high (HV) training volumes] were used to collect the following: 7-day dietary and exercise logs, and blood concentration of T. Anthropometric measurements was taken prior to data collection. A one-time BMD measure (after the training weeks) and VO2max-HR regressions were utilized to calculate EEE. Results: Overall, EA presented as 27.6 ± 10.7 kcal/kgFFM·d-1 with 35% (n = 5) of participants demonstrating increased risk for ED. Examining male triad components, 64.3% presented with LEA (≤ 30 kcal/kgFFM·d-1) while participants presented with T (1780.6 ± 1672.6 ng/dl) and BMD (1.31 ±.09 g/cm2) within normal reference ranges. No differences were found across the 2 training weeks for EI, with slight differences for EA and EEE. Twenty-five participants (89.3%) under-ingested CHO across both weeks, with no differences between weeks. Conclusion: Majority of endurance-trained male athletes presented with one compromised component of the triad (LEA with or without ED risk); however, long-term negative effects on T and BMD were not demonstrated. Over 60% of the participants presented with an EA ≤ 30 kcal/kgFFM·d-1, along with almost 90% not meeting CHO needs. These results suggest male endurance-trained athletes may be at risk to negative health outcomes similar to mechanistic behaviors related to EA with or without ED in female athletes

    Relationship between socio-demographic correlates and human development index with physical activity and sedentary time in a cross-sectional multicenter study

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    © The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativeco mmons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.Background: Socio-demographic correlates and human development index (HDI) are associated with self-reported physical activity, but only a few studies have focused on device-measured physical activity and sedentary time in Latin America. We examined the relationship between socio-demographic correlates and HDI with physical activity and sedentary time in a cross-sectional study. Methods: We based our analyses on 2522 (53.1% women; 18-65 years [mean age 38.3 years]) adults drawn from the eight Latin America countries. Physical activity (light, moderate, vigorous, and moderate-to-vigorous intensity and steps) and sedentary time were assessed using Actigraph GT3X + accelerometers. Sex, age, and race/ethnicity were self-reported. The HDI country information was obtained from the United Nations Development Program. Results: For the age, ethnicity, vigorous physical activity and steps/day, there were significant differences between high and very high HDI countries. Women and younger age presented lower sedentary time than men and older. In moderate-to-vigorous physical activity, we found lower duration in women (-13.4 min/week), younger age (-0.1 min/week), and white/caucasian (-2.7 min/week) than men, older ages and mixed ethnicity. Women (-1266.5 steps/week) and very high HDI (-847.3 steps/week) presented lower steps than men and high HDI. Black (2853.9 steps/week), other (1785.4 steps/week), and white/caucasian ethnicity (660.6 steps/week) showed higher steps than mixed ethnicity. Conclusions: Different socio-demographic correlates are associated with physical activity intensity; however, HDI is associated with vigorous physical activity and steps in the Latin American region, which can in turn guide policies to promote physical activity in the region.info:eu-repo/semantics/publishedVersio
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