Comparison of basal metabolic rate by indirect calorimetry and predictive model

The objective of this study was to compare the values of basal metabolic rate (BMR) obtained by indirect calorimetry (IC) and by predictive model (PM). Methodology: 6 women, age (23.8 ± 3.1 years), height (165 ± 5.8 cm), body mass (55.9 ± 4.9 kg), fat free mass (43 ± 2.1 kg), fat body mass (12.9 ± 3.3 kg), percentage of body fat (22.8 ± 4.2%) were subjected to the test of IC. The IC test was done early in the morning, after 12 hours of fasting, without attainment of physical activity within the last 24 hours and abstinence of alcohol in the last 48 hours. Initially, the volunteers remained at rest for 20 minutes, followed by 20 minutes of measurement by gas analyzer VO2000. To obtain the BMR by the EP the Harris Benedict formula was used , applied for women between 15-74 years: 655.0955 + 9.5634 (weight kg) + 1.8496 (height cm) - 4.6756 (age). For the processing of data the statistical program Instat was used through the paired t test (p \u3c0.05), and the results were expressed as mean and standard deviation of the mean. Results: The value of BMR through the IC was 1423.0±6 calories and through PM 1383.5±6 calories, with no statistically significant differences between the two methods. There was no significant difference between the methods, and thus, the PM can be considered a useful tool to estimate the BMR, as a more accessible and less costly method to this population

Determination of blood glucose threshold for indirect method using the heart rate in runners

The Anaerobic Threshold (AT) is a parameter highly used for physical training prescription. The determination of AT can be performed by direct and indirect methods. The aim of this study was to determine one indirect method to predict the effort intensity that match to Blood Glucose Threshold (BGT), using the maximal Heart Rate from one incremental test in treadmill (HRmax) in runners, 37.57±2.87 years (n=7). The protocol consisted of one incremental test in treadmill, with initial speed of 8 km.h-1, increased by 1 km.h-1 every 3 minutes until the voluntary exhaustion. Blood glucose and HR measurements were done before the test and after each stage. The individual BGT was determinated in the minor point observed in the blood glucose kinetic. The medium percentage of HR maximal of the test corresponding to the HR in the effort intensity in the BGT was 89.17%. To determinate the speed effort in the BGT, a dispersion graphic (HR x BGTspeed) and the tendency’s line equation of the linear regression were used (y=0.0932x–3.7541, R2 = 0.8897). It was concluded that it is possible to determinate the effort intensity in the BGT, indirectly, over the equation BGTspeed (Km.h-1)=0.0932(89.17% of the HRmax in absolute value)–3.7541 or, the summary equation, BGTspeed=0.083(HRmax)-3.7541 for this population. However, other researches are necessary to validate these results

Effects of warm-up before stretching on flexibility and torque development in elderly

The purpose of the study was to analyze the effect of warm up exercises on flexibility and torque development of elderly subjects submitted to a protocol of hamstring muscles stretching. 28 subjects (9 men and 19 women), aged 66.4±6 years, volunteered for this study. Subjects were randomly divided into 2 protocols: a stretching protocol (group A) and a warm up and stretching protocol (group B). Both groups received the intervention for 4 weeks, with three sessions per week, consisting of 6 bouts of active stretching lasting 30 seconds. Subjects were evaluated on selection (T1), immediately before the intervention (T2), immediately after (T3) and a month after (T4) the intervention period for measures of knee extension range of motion (ROM) and angle with a goniometer and for active and passive peak torque (Nm s-1) at 60°/s and 2°/s respectively using a isokinetic dynamometer. Anova Two-Way and a post hoc analysis using the Tukey’s test were applied to test the differences between and within groups. Both groups presented reduction of the knee extension range of motion deficit (p=0.001), increase of the active peak torque flexor in eccentric (p=0.003) and concentric (p=0.015) phases, and reduction of the peak torque angle of the knee flexors in the eccentric phase (p=0.046) when comparing T3 with T2 for both groups, without significant difference between groups. The passive peak torque did not vary significantly (p\u3e0.05) between the evaluations. The pre-exercise warm up was unable to elicit differences in flexibility and torque development of the hamstrings in elderly subjects

Blood lactate kinetics during four sets of bench press with 75% of 1RM

The purpose of the study was to analyze blood lactate kinetics during bench press exercise. 7 resistance-trained men (aged 21.66 ± 0.57 years, body mass 84.33 ± 9.50Kg, height 178.33 ± 0.05 cm, BMI 26.46 ± 2.11 kg/m2) volunteered for the study. The first session consisted of a 1-RM bench press test. After 48 hours, subjects returned and performed a warm up (20 repetitions with 40% 1-RM) and 4 sets of 8 repetitions with an intensity corresponding to 75% of 1-RM, separated by a 2-minute rest interval. Blood samples were collected at rest (R), after the warm up (W), at the end of each rest interval (INT) and immediately after each set (SET) for further lactate concentration analysis using a lactate analyzer (YSI, SPORT 1500®). Results indicate a trend to glucose metabolism, as shown by blood lactate concentration. The higher values at the end of each rest interval indicate that lactate was removed to blood. Blood lactate concentrations were smaller after each set, when compared to the previous interval. These results could be caused by a reduction in glucose metabolism during the sets or even by lactate removal by other tissues, as this is possibly the blood lactate kinetics during such a protocol

Effects of ovariectomy and resistance training on oxidative stress markers in the rat liver

OBJECTIVE: The objective of this study was to assess the effects of resistance training on oxidative stress markers in the livers of ovariectomized rats. METHOD: Adult Sprague-Dawley rats were divided into the following four groups (n = 8 per group): sham-operated sedentary, ovariectomized sedentary, sham-operated resistance training, and ovariectomized resistance training. During the resistance training period, the animals climbed a 1.1-m vertical ladder with weights attached to their tails; the sessions were conducted 3 times per week, with 4-9 climbs and 8-12 dynamic movements per climb. The oxidative stress was assessed by measuring the levels of reduced glutathione and oxidized glutathione, the enzymatic activity of catalase and superoxide dismutase, lipid peroxidation, vitamin E concentrations, and the gene expression of glutathione peroxidase. RESULTS: The results showed significant reductions in the reduced glutathione/oxidized glutathione ratio (4.11±0.65 nmol/g tec), vitamin E concentration (55.36±11.11 nmol/g), and gene expression of glutathione peroxidase (0.49±0.16 arbitrary units) in the livers of ovariectomized rats compared with the livers of unovariectomized animals (5.71±0.71 nmol/g tec, 100.14±10.99 nmol/g, and 1.09±0.54 arbitrary units, respectively). Moreover, resistance training for 10 weeks was not able to reduce the oxidative stress in the livers of ovariectomized rats and induced negative changes in the hepatic anti-oxidative/oxidative balance. CONCLUSION: Our findings indicate that the resistance training program used in this study was not able to attenuate the hepatic oxidative damage caused by ovariectomy and increased the hepatic oxidative stress

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Efeitos do treinamento resistido sobre a expressão gênica de moléculas envolvidas na oxidação de gordura e na lipogênese no fígado de ratas ovariectomizadas

Decreased levels of estrogen are associated with hepatic steatosis (HS), through changes in gene expression of molecules related to fat oxidation and lipogenesis. Both resistance training (RT) and endurance training (ET) prevents the HS in ovariectomized (Ovx) rats. However, the molecular events associated with this process were only investigated for ET but not for RT. Aims: Thus, the aim of this study was to investigate the effects of Ovx and RT on the gene expression of molecules related to fat oxidation and lipogenesis in the liver of rats. Methods: Sprague-Dawley adult female rats were grouped into four groups (n = 6 per group): sham-operated sedentary (Sham-Sed); Ovx sedentary (Ovx-Sed); sham-Rt and Ovx- Rt. A 10-week RT period, during which the animals climbed a 1.1-m vertical ladder with weights attached to their tails, was used. The sessions were performed three times a week, with 4-9 climbs and 8-12 dynamic movements per climb. Gene expression was analyzed by RT-PCR by the ΔΔCt method. Results: The estrogen deficiency associated with ovariectomy decreased the gene expression of molecules related to fat oxidation, carnitine palmitoyltransferase I (53%) and β-hydroxyacyl-CoA dehydrogenase (27%), and increased of molecules related to lipogenesis, sterol regulatory element-binding protein-1c (106%), acetyl-CoA carboxilase (ACC) (72%) and stearoyl CoA desaturase-1 (109%), which had their expression restored to the RT, with the exception of the ACC. Conclusions: The present results indicate that the RT may have important effects on the prevention of HS in Ovx animals, possibly through the restoration in gene expression of molecules related to hepatic lipid metabolismFinanciadora de Estudos e ProjetosA deficiência de estrógeno está associada à esteatose hepática (EH), por meio de alteração na expressão gênica de moléculas relacionadas à oxidação de gordura e à lipogênese. Tanto o treinamento resistido (TR), quanto o treinamento de endurance (TE) previne a EH em ratas ovariectomizadas (Ovx). No entanto, os eventos moleculares somente foram investigados em relação ao TE e não ao TR. Objetivo: investigar os efeitos da Ovx e do TR sobre a expressão gênica de moléculas relacionadas tanto a oxidação de gordura quanto a lipogênese no fígado de ratas. Métodos: Ratas Sprague-Dawley adultas foram divididas em 4 grupos (n = 6 por grupo): sham operado sedentário (Sham-Sed), Ovx sedentário (Ovx-Sed), sham operado TR (Sham-Tr) e Ovx-Tr. O protocolo de TR exigiu dos animais a escalada de uma escada vertical de 1,1 m com pesos atados as suas caudas. Cada sessão consistiu de 4-9 escaladas, com intervalo de 2 min entre as escaladas, realizado com freqüência semanal de 3 vezes durante 10 semanas. A análise da expressão gênica foi realizada por PCR-RT pelo método ΔΔCt. Resultados: A Ovx diminui significativamente a expressão gênica das moléculas relacionadas à oxidação de gordura; carnitina palmitoil transferase I 53% e da hidroxiacil-CoA desidrogenase 27%, e aumentou das moléculas relacionadas com a lipogênese; proteína 1c ligadora do elemento regulado por esteróis 106%, acetil-CoA carboxilase 72% e estearoil-CoA dessaturase-1 109%, as quais tiveram suas expressões restauradas com o TR, com exceção da ACC. Conclusão: Os resultados presentes sugerem que o TR pode ter importantes efeitos sobre a prevenção da EH em animais Ovx, possivelmente por meio da restauração da expressão gênica de moléculas relacionadas ao metabolismo lipídico hepático

Efeitos da ovariectomia, do treinamento resistido e da terapia de reposição hormonal sobre a expressão gênica de marcadores da biogênese mitocondrial em cérebro de ratas

Decreased levels of estrogen are associated with a decline in brain bioenergetics, which could be associated with a decrease in mitochondrial biogenesis (MB). Endurance training (ET) has been shown to increase markers of MB within the brain. However, the molecular events associated with this process were only investigated for ET but not for resistance training (RT) and hormone replacement therapy (HRT). In the study, we attempted to investigate the effects of ovariectomy (Ovx), RT and HRT on markers of MB (mRNA expression of peroxisome proliferator - activated receptor - γ coactivator 1 (PGC - 1α), nuclear respiratory fator- 1 (NRF - 1), and mitochondrial transcription factor A (TFAM)) in specific brain regions, cortex (CX), hippocampus (HC), and hypothalamus (HT) in rats. Sprague - Dawley adult female rats were grouped into six groups: sham - operated sedentary (Sham - Sed); Ovx - Sed; Sham - RT; Ovx - RT; Ovx – Sed - HRT and Ovx - RT - HRT. The animals in HRT groups received subcut aneously implanted silastic capsules with a solution of 180 μg 17β - estradiol/ml sunflower oil. A 12- week RT period, during which the animals climbed a 1.1 - m vertical ladder with weights attached to their tails, was used. The sessions were performed once every 3 days, with 4 - 9 climbs. Gene expression was analyzed by RT - PCR by the ∆∆Ct method. The Ovx decreased the gene expression of molecules related to BM, PGC - 1α (28%), NRF - 1 (29%) and TFAM (20%) in the HC. These Ovx - induced lower gene expressions were totally restored in this structure by RT. RT increased the markers of MB, PGC - 1a (~33%), NRF - 1 (~31%) and TFAM (~44%) in CX, HC and HT. These findings suggest that OVX decreases brain MB, in our data observed in HC, and RT increases brain MB, which may have important implications with respect to various central nervous system diseases and age - related dementia that are often characterized by mitochondrial dysfunction. Stimulation or enhancement of mitochondrial biogenesis may prove a novel neuroprotective strategy in the future.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)A diminuição dos níveis dos hormônios ovarianos está associado a um declínio na bioenergética cerebral, o que poderia estar associado a uma diminuição da biogênese mitocondrial (BM). O treinamento de endurance (TE) foi demonstrado aumentar a expressão gênica dos marcadores da BM em diferentes regiões do cérebro. No entanto, os eventos moleculares da BM ainda não foram investigados em outros tipos de treinamento, como, o treinamento resistido (TR) ou em outros tipos de modelo experimental, como a ovariectomia (Ovx) e a terapia de reposição hormonal (TRH). Assim, o objetivo deste trabalho foi analisar os efeitos da Ovx, do TR e da TRH sobre a expressão gênica dos marcadores chaves da biogênese mitocondrial, o coativador 1α do receptor gama ativado por proliferador de peroxissoma (PGC-1α), o fator respiratório nuclear 1 (NRF-1) e o fator de transcrição mitocondrial A (TFAM) em diferentes regiões do cérebro, córtex (CX), hipocampo (HC) e hipotálamo (HT) de ratas. Trinta e seis ratas adultas Sprague - Dawley foram distribuídas em seis grupos experimentais (n = 6 por grupo): (I) sedentário sham-operação (Sed-Sham); (II) Ovx - Sed; (III) Sham-TR; (IV) Ovx - TR; (V) Ovx – Sed - TRH e (VI) Ovx- TR- TRH. Os animais dos grupos Ovx foram submetidos aos procedimentos cirúrgicos de remoção bilateral dos ovários, dos grupos TRH foram submetidos aos procedimentos cirúrgicos de implantação subcutânea de cápsulas silásticas preenchidas com uma solução de 180 μg de 17 β - estradiol/ml de óleo de girassol e os animais dos grupos TR foram submetidos a doze semanas de treinamento resistido progressivo em escada, sendo as sessões de treinos realizadas uma vez a cada 3 dias. A expressão gênica foi analisada por PCR-RT e determinada pelo método do ∆∆Ct. O grupo Ovx - Sed apresentou uma menor expressão gênica dos marcadores chaves da BM no HC quando comparado ao grupo Sham - Sed. A expressão do PGC - 1α foi 28% menor, do NRF - 1 29% menor e do TFAM 20% menor. Estas menores expressões gênicas no HC foram restauradas nas ratas do grupo Ovx - TR e parcialmente restauradas nas ratas do grupo Ovx – Sed - TRH. Adicionalmente, as ratas do grupo Sham-TR apresentaram maior expressão gênica nas três áreas investigadas (CX, HC e HT), PGC - 1α ~33% maior, NRF - 1 ~31% maior e TFAM ~44% maior. Estes resultados sugerem que o declínio na concentração circulante dos hormônios ovarianos diminui a BM no cérebro, em nossos resultados observados no HC, e que o TR pode aumentar a BM no cérebro, o que pode ter importantes implicações no que diz respeito a várias doenças do sistema nervoso central e demência relacionada com a idade que são frequentemente caracterizadas por disfunção mitocondrial. Sendo assim, a estimulação da BM cerebral estimulada pelo exercício pode ser uma importante estratégia de neuroproteção