Bioenergetic analysis of female volleyball

Volleyball is a demanding sport typified by repeated high intensity bouts of activity consisting of jumping, spiking, diving, and running. Practice sessions for collegiate level play generally last from two to three hours. The total energy requirement for extended practice sessions has not been directly measured and compared to dietary intake to assess whether collegiate athletes’ energy intake meets the energy demand of the sport. The purpose of this study was to establish the energy balance of female collegiate volleyball athletes during typical team training days. A bioenergetic analysis was conducted by directly measuring oxygen consumption (V 02) during actual training sessions, analyzing detailed records of the energy cost of all other activities throughout training days, and comparing the total kcal cost of activity to the dietary intake of athletes. Twelve female collegiate volleyball athletes (20.5 ±1.2 years of age) were asked to wear a portable metabolic measurement device for approximately 45 min during their regularly scheduled team practice sessions under the direct supervision of team coaches; data from one athlete was excluded due to illness on data collection days. Athletes kept detailed records of all physical activity and dietary intake for three 24 hour periods on three regular team training days. The mean V 0 2 during on-court data collection was 25.03 ±3.12 ml/kg/min during approximately 47.1 ± 3.7 min of volleyball play. The mean energy cost during on-court data collection was 419 ± 85 kcal. Analysis of activity records of the three 24 hour periods on team training days revealed a mean daily energy cost of 3630 ± 442 kcal. The mean daily kcal intake from dietary records was 1861 ±516 kcal. There was a significant difference (p = 0.001) between the energy expenditure (EE) and the energy intake (El) revealing a negative 1769 ± 507 kcal balance which represented a 48.7% negative energy balance. In conclusion, this study revealed greater EE on training days compared to El and pointed to a need for further research to investigate nutritional supplementation and/or education to help athletes attain an optimal energy balance essential for health, training, and performance

Bioenergetic Analysis of Female Volleyball

Volleyball is a demanding sport typified by repeated high intensity bouts of activity consisting of jumping, spiking, diving, and running. Practice sessions for collegiate level play generally last from two to three hours. The total energy requirement for extended practice sessions has not been directly measured and compared to dietary intake to assess whether collegiate athletes\u27 energy intake meets the energy demand of the sport. The purpose of this study was to establish the energy balance of female collegiate volleyball athletes during typical team training days. A bioenergetic analysis was conducted by directly measuring oxygen consumption (V0 2) during actual training sessions, analyzing detailed records of the energy cost of all other activities throughout training days, and comparing the total kcal cost of activity to the dietary intake of athletes. Twelve female collegiate volleyball athletes (20.5 ± 1.2 years of age) were asked to wear a portable metabolic measurement device for approximately 45 min during their regularly scheduled team practice sessions under the direct supervision of team coaches; data from one athlete was excluded due to illness on data collection days. Athletes kept detailed records of all physical activity and dietary intake for three 24 hour periods on three regular team training days. The mean VO2 during on-court data collection was 25.03 ± 3.12 ml/kg/min during approximately 47.1 ± 3.7 min of volleyball play. The mean energy cost during on-court data collection was 419 ± 85 kcal. Analysis of activity records of the three 24 hour periods on team training days revealed a mean daily energy cost of 3630 ± 442 kcal. The mean daily kcal intake from dietary records was 1861 ± 516 kcal. There was a significant difference (p = 0.001) between the energy expenditure (EE) and the energy intake (EI) revealing a negative 1769 ± 507 kcal balance which represented a 48.7% negative energy balance. In conclusion, this study revealed greater EE on training days compared to EI and pointed to a need for further research to investigate nutritional supplementation and/or education to help athletes attain an optimal energy balance essential for health, training, and performance

The Availability Heuristic, Intuitive Cost-Benefit Analysis, and Climate Change

Because risks are on all sides of social situations, it is not possible to be “precautionary” in general. The availability heuristic ensures that some risks stand out as particularly salient, whatever their actual magnitude. Taken together with intuitive cost-benefit balancing, the availability heuristic helps to explain differences across groups, cultures, and even nations in the assessment of precautions to reduce the risks associated with climate change. There are complex links among availability, social processes for the spreading of information, and predispositions. If the United States is to take a stronger stand against climate change, it is likely to be a result of available incidents that seem to show that climate change produces serious and tangible harm

Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.Peer reviewe

and Juvenile Justice

b

Recording of the saphenous vein compliance by an ultrasonic echo-tracking device in the dog: effects of S 18149

1. Saphenous vein reactivity was recorded in the anaesthetized dog by use of an ultrasonic echo-tracking device to measure the internal diameter of the vein and to calculate the venous compliance. This method was used to investigate the effects of a new partial α(1)/α(2)-adrenoceptor agonist, S 18149, on the canine saphenous vein in vivo after intravenous (i.v.) or oral administration. 2. Venoconstrictions induced by i.v. or local administration of compounds were evaluated by continuous recording of the internal diameter of the saphenous vein with the echo-tracking method. Venous compliance was calculated in two ways: (1) as the slope of the diameter-pressure curve obtained by increasing the venous pressure with an inflatable cuff and (2) in veins in which pressure was higher than 12 mmHg, pulsatile variations in the venous diameter and venous pressure were detected and used to calculate the pulsatile compliance of the vein. 3. S 18149 administered i.v. at 0.5 μg kg(−1) min(−1) for 10 min induced a decrease in the saphenous vein diameter (−15±3%) and blood flow (−72±6%) associated with an increase in saphenous vein resistance; at the dose used, S 18149 did not modify venous pressure and caused only a weak increase in arterial pressure (+7±2 mmHg). 4. The pulsatile compliance of the saphenous vein averaged 8.65±1.37 mm(2)×100 mmHg(−1) in control dogs and was significantly decreased to 5.13±0.68 mm(2)×100 mmHg(−1) in the same animals after treatment with S 18149 at 100 μg kg(−1) per os (n=10). The saphenous vein compliance calculated with the increased external pressure method averaged 24.90±1.49 μm mmHg(−1) in control dogs and was significantly reduced in the same animals after treatment with S 18149 at 100 μg kg(−1) per os to 9.06±3.42 μm mmHg(−1) (n=5). When constrictions of the vein were induced with increasing doses of (−)-phenylephrine, injected locally at 1, 3 or 6 μg min(−1), only the responses obtained with the lower dose of (−)-phenylephrine were increased in dogs treated with S 18149 100 μg kg(−1) per os (−16±4% versus −4±3%, n=5). 5. These results show that the high resolution echo-tracking device previously used for arterial compliance measurements, allows the detection of pulsatile changes in the canine saphenous vein and thus permits calculation of both the pulsatile and the static compliance of superficial veins in vivo. Using this technique, we have demonstrated that the novel α-adrenoceptor agonist S 18149 constricts the canine saphenous vein in vivo and decreases the saphenous vein compliance after oral administration