Energy expenditure during multiple sets of leg press and bench press

The purpose of this study was to quantify energy expenditure (EE) during multiple sets of leg press (LP) and bench press (BP) exercises in 10 males with at least 1 yr of resistance training (RT). The subjects underwent two sessions to determine 1 repetition maximum (1RM) on the BP and LP and one protocol consisting of a warm up and 4 sets for 10 repetitions at 70% 1RM with a 3-min rest period between sets for each exercise. Energy expenditure was calculated as the sum of oxygen uptake (aerobic component), EPOC, and lactate production (anaerobic component). There were no significant differences in EE between exercises for sets 1 to 4 and the total energy expended. However, statistical analysis revealed a significant difference (P<0.05) between exercises in RT economy (BP, 0.0206 ± 0.0044 kcal·kg-1 vs. LP, 0.0051 ± 0.0015 kcal·kg-1). Within exercise comparison showed set 4 was significantly different from sets 1 and 3 for BP, and for LP a significant difference was found between set 4 and sets 1, 2 and 3. Our results point to an increase in EE during multiple sets at 70% 1RM and show that in spite of the difference in muscle mass involved and total work done during each type of exercise, EE was not different due to greater economy during the LP.

CCST income and expenditure

Includes bibliography

Productivity, social expenditure and income distribution in Latin America

This paper discusses the role of institutions and structural change in shaping income inequality. It is argued that while social expenditure and direct redistribution are crucial for improving income distribution, sustainable equality requires structural change to create decent jobs. The relative importance of these variables in different countries is analyzed and a typology suggested. It is argued that the most equal countries in the world combine strong institutions in favor of redistribution and knowledge-intensive production structures that sustain growth and employment in the long run. Both institutions and the production structure in Latin America fail to foster equality and this explains its extremely high levels of inequality. The last decade witnessed significant advances in reducing inequality in Latin America, but these advances are threatened by slow productivity growth and weak structural change.

Comparison of predictive equations for resting energy expenditure in overweight and obese adults

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Development of a synbiotic low-calorie beverage made from soy and yacon extracts

The objective of this study was to develop a new low-calorie symbiotic beverage made from yacon (prebiotic source) and soy extracts, containing probiotic Bifidobacterium animalis ssp. lactis BB-12. The synbiotic beverage was first produced with a range of sucrose concentrations in order to determine ideal sweetness by an acceptance test using a “just-about-right scale”. Sucrose was then replaced by sucralose or aspartame to produce sugar-free beverages. Characteristics including viable cell numbers, physicochemical properties, sensorial characteristics and fructooligosaccharides content were investigated. The ideal sweetness of the beverages with sucrose, aspartame and sucralose were 7.28%, 0.0486% and 0.0167%, respectively. Sucralose exhibited higher scores in acceptance test and was used to replace sucrose in the low-calorie symbiotic beverage. The synbiotic beverage exhibited counts of Bifidobacterium spp. of 108 CFU·mL-1 , sufficient condition to be considered probiotic. The chemical composition of the product was (g/100 g): 2.91 of protein, 1.41 of fat, 2.41 of total carbohydrate; 0.82 of FOS and 148.22 Kj of energy value. The synbiotic beverage developed in this study may be successful in health applications, due to their functional ingredients (soy, probiotic bacteria and yacon prebiotics) that can afford benefits to health or can present disease-preventing properties, beyond their inherent nutritional value. In addition this low-calorie beverage can be consumed by diabetic individuals and people concerned about the ingestion of calories.

Calorie restriction increases cerebral mitochondrial respiratory capacity in a NO center dot-mediated mechanism: Impact on neuronal survival

Calorie restriction (CR) enhances animal life span and prevents age-related diseases, including neurological decline. Recent evidence suggests that a mechanism involved in CR-induced life-span extension is NO-stimulated mitochondrial biogenesis. We examine here the effects of CR on brain mitochondrial content. CR increased eNOS and nNOS and the content of mitochondria] proteins (cytochrome c oxidase, citrate synthase, and mitofusin) in the brain. Furthermore, we established an in vitro system to study the neurological effects of CR using serum extracted from animals on this diet. In cultured neurons, CR serum enhanced nNOS expression and increased levels of nitrite (a NO product). CR serum also enhanced the levels of cytochrome c oxidase and increased citrate synthase activity and respiratory rates in neurons. CR serum effects were inhibited by L-NAME and mimicked by the NO donor SNAP. Furthermore, both CR sera and SNAP were capable of improving neuronal survival. Overall, our results indicate that CR increases mitochondrial biogenesis in a NO-mediated manner, resulting in enhanced reserve respiratory capacity and improved survival in neurons. (C) 2012 Elsevier Inc. All rights reserved.

Serum from Calorie-Restricted Rats Activates Vascular Cell eNOS through Enhanced Insulin Signaling Mediated by Adiponectin

eNOS activation resulting in mitochondrial biogenesis is believed to play a central role in life span extension promoted by calorie restriction (CR). We investigated the mechanism of this activation by treating vascular cells with serum from CR rats and found increased Akt and eNOS phosphorylation, in addition to enhanced nitrite release. Inhibiting Akt phosphorylation or immunoprecipitating adiponectin (found in high quantities in CR serum) completely prevented the increment in nitrite release and eNOS activation. Overall, we demonstrate that adiponectin in the serum from CR animals increases NO center dot signaling by activating the insulin pathway. These results suggest this hormone may be a determinant regulator of the beneficial effects of CR.

Anaerobic energy expenditure and mechanical efficiency during exhaustive leg press exercise

[EN] Information about anaerobic energy production and mechanical efficiency that occurs over time during short-lasting maximal exercise is scarce and controversial. Bilateral leg press is an interesting muscle contraction model to estimate anaerobic energy production and mechanical efficiency during maximal exercise because it largely differs from the models used until now. This study examined the changes in muscle metabolite concentration and power output production during the first and the second half of a set of 10 repetitions to failure (10RM) of bilateral leg press exercise. On two separate days, muscle biopsies were obtained from vastus lateralis prior and immediately after a set of 5 or a set of 10 repetitions. During the second set of 5 repetitions, mean power production decreased by 19% and the average ATP utilisation accounted for by phosphagen decreased from 54% to 19%, whereas ATP utilisation from anaerobic glycolysis increased from 46 to 81%. Changes in contraction time and power output were correlated to the changes in muscle Phosphocreatine (PCr; r = -0.76; P<0.01) and lactate (r = -0.91; P<0.01), respectively, and were accompanied by parallel decreases (P<0.01-0.05) in muscle energy charge (0.6%), muscle ATP/ADP (8%) and ATP/AMP (19%) ratios, as well as by increases in ADP content (7%). The estimated average rate of ATP utilisation from anaerobic sources during the final 5 repetitions fell to 83% whereas total anaerobic ATP production increased by 9% due to a 30% longer average duration of exercise (18.4 +/- 4.0 vs 14.2 +/- 2.1 s). These data indicate that during a set of 10RM of bilateral leg press exercise there is a decrease in power output which is associated with a decrease in the contribution of PCr and/or an increase in muscle lactate. The higher energy cost per repetition during the second 5 repetitions is suggestive of decreased mechanical efficiency.