Swimming rats’ model: influence of age and density on the maximal lactate steady state test

The aim of this study was to verify wether the density plays a significant role in the swimming model for rats. To verify such possibility the rats’ weight in the water was considered as an additional workload beyond the load increment. Forty Wistar rats divided in groups of 90, 120 and 210 days old were used. The animals had their hydrostatic weight and density determined by an apparatus for water weighing. Later, all the rats were evaluated at the maximal lactate steady state (MLSS) test adapted for swimming rats. Statistic Analysis was performed by Anova one-way and Scheffé post hoc test (p\u3c0.05). Results showed hydrostatic weight (g) and density (g/cm3) of 10.2 and 0.997, 16.8 and 1.011, 21.4 and 1.017 for G90, G120 and G210, respectively, with significant differences between ages. Blood lactate concentrations at the MLSS were 4.1, 4.8 and 5.5 mmol/L for G90, G120 and G210, respectively and were not significantly different; but it showed a trend to increase in agreement with the presented ages. In contrast, the workloads seemed to decrease with age in the conventional method (5.3, 4.7, 4.5% of body weight for G90, G120 and G210, respectively), however when the hydrostatic weight was considered, an increase in effort was found in agreement with age (7.9, 8.4, 8.5% of body weight for G90, G120 and G210, respectively). This fact could be an explanation for the higher lactate concentration found in older groups. So, it is possible to suggest that in the convencional workload method the 210 days group has its aerobic capacity underestimated because these rats are denser than those 90 days animals

Comparison of aerobic capacity determined by the lactate minimum test among guard, forward and forward-center positions in basketball players

To aim of this study was to verify the aerobic capacity by lactate minimum test (LM) among different positions in professional basketball players. Twelve high performance basketball players (12 Major National Leagues, 26.7± 3.2 years) were evaluated by LM. The method of lactate elevation consisted of 6 maximum sprints of 35 m separated by 10 s of recovery each (Running Anaerobic Sprint Test). The progressive phase in LM consisted of 4 periods of 3 min each at 8, 10, 11 and 12 Km/h. After lactate elevation phase and progressive periods, 25μL samples of blood were collected to determine peak lactate (PL) concentration and relative lactate minimum concentration (LACc) respectively. The running speed at the LM was taken when the gradient of the line was zero. Anova one-way statistical was utilized to compare the intensity corresponding LM, LACc and PL (p≤0.05). The velocity (Km/h) of LM did not differ among positions: Guard LM= 9.46±0.17 Km/h; Forward LM= 9.60±0.68 Km/h and Forward-Center LM= 9.64±0.25 Km/h. The LACc did not differ: Guard LM= 3.55±0.51 mmol/L; Forward LM= 3.48±1.63 mmol/L and Forward-Center LM= 4.00±0.43 mmol/L. No changes occurred in PL: Guard LM= 8.35±1.41 mmol/L; Forward LM= 8.16±1.47 mmol/L and Forward-Center LM= 8.76±1.20 mmol/L. The aerobic capacity determined by LM did not differ among guard, forward and forward center basketball players

Effect of cadence to determine critical power using non- exhaustive protocol in cycle ergometer

In cycling the exercise power (w) is a product of cadence (rpm) and kilopounds (kp). The purpose of this study was to check the pedaling frequency influence on critical power (CP) determined using non-exhaustive aerobic capacity test (Chassain, 1986). Adult men (n=2) were submitted to four powers (100, 120, 130 and 150 w) in two different cadences (40 and 70 rpm) in cycloergometer (Monark 894 E). Two exercise bouts lasting 180 seconds by 90 seconds of interval were performed at an equal intensity. For each intensity, delta heart rate (ΔHR) was determined by subtraction of the maximum heart rate (MHR) at the end of the first effort from the MHR at the end of the second effort (ΔHR= MHR 2 – MHR 1). Individual linear interpolation of ΔHR enabled determination of a null Δ equivalent to the CP. The mean value of CP at 70 rpm was 83.8 ± 22.5 W while the CP at 40 rpm was 100.2 ± 8.4 Watts. The mean value of CP at 40 rpm was 17% higher than at 70 rpm. The cadence can be decisive to determine the CP using non-exhaustive protocol

Influence of the pedaling cadence in determining the critical power in the cycloergometer

The objective of this study was to determine the critical power (PCrit) using intensities of 230, 250, 270 and 300 Watts (W) under different speeds ranging from pedaling (60 and 80 rotations per minute - rpm). Two young adults, male, healthy and active, with an average age 22 years were selected. The test was conducted in cycle model Monark® ergomedic 894 E. The depth charges were chosen randomly, changing the relationship load and speed from the cadence. The exhaustion criterion was the voluntary withdrawal or failure to maintain the speed for 5 seconds. To determine the PCrit and anaerobic work capacity (CTA) the linear model of power 1/tempo x exhaustion was used. The results are expressed as mean ± standard deviation of the mean. The t Student test for independent samples for comparison PCrit CTA and the cadences of 60 and 80 rpm was used. During the tests the heart rate (bpm) every 15 seconds was recorded. The results of PCrit to 60 rpm (Pcrit60rpm) and PCrit at 80 rpm (Pcrit80rpm) were not statistically different (Pcrit60rpm=208.1±12.0 W and Pcrit80rpm=165.5±33.2 W). The average Pcrit60rpm was 25% higher than Pcrit80rpm. The absolute values of CTA were not different (CTA60rpm=10316.6±3766.7, CTA80rpm=15996.5±5247.4). The CTA80rpm was 55% higher compared to CTA60rpm. Thus, one can conclude that the cadence of pedaling at 60 rpm and 80 did not statistically influence the values of PCrit and CAT. However, the percentage of Pcrit80rpm was significantly below Pcrit60rpm

Comparison between critical speed and maximal lactate steady state in amateur distance runners

The purpose of this study was to compare maximal lactate steady state (MLSS) and the critical speed (CS) in distance runners. Six male athletes were submitted to the CS test, to linear regression of the distances (800, 1.500, 3.000 and 5.000m). The CS was determined by the angular coefficient of the linear regression (Distance x Time). The predicted workloads for the MLSS determination were: 103; 100 and 98% of the CS, randomized and in a continuous way in subsequent days. In MLSS test, the athletes run for 30 min, and it was collected blood samples (25μL) at 10th and 30th min, to determine the lactate concentration (YSI 1500 sport). It was determined MLSS the non lactate variation higher than 1.0 mmol/L between the 10th and 30th minute. The MLSS occurred for 5 athletes on the 100% intensity of CS (15.1 ± 1.5 Km/h) and for 1 athlete on the 95% (14.3 Km/h). At 100% of CS, the MLSS concentration was: rest lactate (RL)= 1.0 ± 0.3 mmol/L; 10thmin= 3.28 ± 0.64; 30th 3.92 ± 1.14. At 103% of CS, the MLSS concentration was: RL= 1.10 ± 0.41 mmol/L; 10thmin= 3.06 ± 1.44; 30th 4.12 ± 1.59. The MLSS occurred at 100% of MLSS. These results showed that the CS is a trustful test to predict the MLSS in distance runners with MLSS velocity at 15Km/h

Effects of fasting on critical velocity and anaerobic capacity determination in running rats

The non-invasive critical power model suggested for aerobic/anaerobic evaluation of human beings was adapted for rats in our Laboratory. The aim of the present study was to verify the effects of 12-hours fasting on the critical velocity (CV) and the anaerobic running capacity (ARC) determination in sedentary rats. 11 adult Wistar rats (90 days old, weighing 395.5 ± 17.6g) were submitted to four exercise tests at 25, 30, 35 and 40m/min (with 48 hours of interval), performed randomly and continuously until exhaustion, for the CV and ARC estimations. The protocol was executed with the rats in the fed state and after 12-hours fasting. The hyperbolic curve velocity versus time to exhaustion (tlim) was linearized to V = CV + ARC/tlim, where the CV and ARC were the linear and slope coefficients, respectively. For comparison of the parameters obtained in the fed state and after fasting, the Student t test for dependent measures was used (p\u3c0.05). The CV (m/min) and ARC (m) were 25.5 ± 1.5 and 21.8 ± 16.4 m in fed state and 22.5 ± 4.2 and 25.9 ± 14.0 m after fasting. The linear regression showed significant values (R2=0.85±0.07 in fed state and 0.88±0.09 after fasting). The 12-hours fasting modified the CV without changing ARC. The results indicate that there is a caution need with the alimentary condition of running rats previously to evaluation test. The physiological characteristics can mask the determination of the aerobic condition, resulting in the inadequate exercise prescription based on the parameters estimated by the non-invasive protocol

Anaerobic And Aerobic Performances In Elite Basketball Players.

THE PURPOSE OF THIS STUDY WAS TO PROPOSE A SPECIFIC LACTATE MINIMUM TEST FOR ELITE BASKETBALL PLAYERS CONSIDERING THE: Running Anaerobic Sprint Test (RAST) as a hyperlactatemia inductor, short distances (specific distance, 20 m) during progressive intensity and mathematical analysis to interpret aerobic and anaerobic variables. The basketball players were assigned to four groups: All positions (n=26), Guard (n= 7), Forward (n=11) and Center (n=8). The hyperlactatemia elevation (RAST) method consisted of 6 maximum sprints over 35 m separated by 10 s of recovery. The progressive phase of the lactate minimum test consisted of 5 stages controlled by an electronic metronome (8.0, 9.0, 10.0, 11.0 and 12.0 km/h) over a 20 m distance. The RAST variables and the lactate values were analyzed using visual and mathematical models. The intensity of the lactate minimum test, determined by a visual method, reduced in relation to polynomial fits (2nd degree) for the Small Forward positions and General groups. The Power and Fatigue Index values, determined by both methods, visual and 3rd degree polynomial, were not significantly different between the groups. In conclusion, the RAST is an excellent hyperlactatemia inductor and the progressive intensity of lactate minimum test using short distances (20 m) can be specifically used to evaluate the aerobic capacity of basketball players. In addition, no differences were observed between the visual and polynomial methods for RAST variables, but lactate minimum intensity was influenced by the method of analysis.42137-4

Transformações urbanas: volume 4

O processo de urbanização ocorrido após a Revolução Industrial, impulsionado com a migração dos trabalhadores rurais e imigrantes estrangeiros que buscavam empregos nas fábricas e indústrias e pela implementação de políticas públicas voltadas para o desenvolvimento urbano após a Segunda Guerra Mundial ocorreu de forma acelerada, desordenada e insustentável do ponto de vista ambiental. É comum nos grandes centros urbanos hoje redes de infraestrutura sobrecarregadas, com acesso insuficiente à água potável, saneamento básico precário, deficiência de transporte público e congestionamentos, além de processos de gentrificação, favelização e de habitação precária. Além disso, a ausência de um planejamento adequado também proporciona a existência de vazios urbanos e áreas subutilizadas, o que aumenta injustiça e a desigualdade social. Nesse contexto, o professor Gustavo Alexandre Cardoso Cantuária, na disciplina “Planejamento, Transformação Urbana e Requalificação Arquitetônica”, do programa de pós-graduação stricto sensu, coordenou trabalhos que apresentassem exemplos de intervenções que representassem impactos efetivos nos contextos urbanos em diferentes escalas: local, de bairro e de cidade. Por meio desses exemplos foi possível analisar as transformações espaciais, morfológicas, arquitetônicas, funcionais, bioclimáticas, sociais, econômicas, sustentáveis, de mobilidade, de identidade entre muitas outras características relevantes, relacionando os problemas pré-existentes, o que se buscou fazer e o que de fato foi ou será executado, pontuando os reflexos positivos e negativos da intervenção. Os trabalhos produzidos, ricos em conteúdo e em recursos gráficos, de exemplos variados de intervenções urbanas em diversos locais do mundo, foram compilados e podem ser conferidos nos 4 e-books desta série “Transformações Urbanas”

Growth of Crassostrea gasar cultured in marine and estuary environments in Brazilian waters

O objetivo deste trabalho foi avaliar o crescimento da ostra-do-mangue Crassostrea gasar cultivada em ambiente marinho e estuarino. As ostras foram cultivadas por 11 meses em sistema de espinhel, em dois locais de estudo – São Francisco do Sul e Florianópolis –, em Santa Catarina. A concentração de clorofila‑α, a temperatura e a salinidade da água foram registradas semanalmente. As ostras foram medidas mensalmente (tamanho da concha e ganho de peso) para avaliar o crescimento. No final do período de cultivo, os pesos médios de carne úmida, carne seca e concha foram determinados, bem como a distribuição das ostras por classes de tamanho. Seis modelos não lineares (logístico, exponencial, Gompertz, Brody, Richards e Von Bertalanffy) foram ajustados aos dados de crescimento das ostras. As médias finais de tamanho da concha foram maiores em São Francisco do Sul do que em Florianópolis. Além disso, as ostras cultivadas em São Francisco do Sul apresentaram distribuição mais uniforme nas classes de tamanho do que aquelas cultivadas em Florianópolis. Os maiores valores médios de peso de carne úmida e peso de concha foram observados em São Francisco do Sul, enquanto o peso da carne seca não diferiu entre os locais. O ambiente estuarino é mais promissor para o cultivo de ostras.The objective of this work was to evaluate the growth of the mangrove oyster Crassostrea gasar cultured in marine and estuarine environments. Oysters were cultured for 11 months in a longline system in two study sites – São Francisco do Sul and Florianópolis –, in the state of Santa Catarina, Southern Brazil. Water chlorophyll‑α concentration, temperature, and salinity were measured weekly. The oysters were measured monthly (shell size and weight gain) to assess growth. At the end of the culture period, the average wet flesh weight, dry flesh weight, and shell weight were determined, as well as the distribution of oysters per size class. Six nonlinear models (logistic, exponential, Gompertz, Brody, Richards, and Von Bertalanffy) were adjusted to the oyster growth data set. Final mean shell sizes were higher in São Francisco do Sul than in Florianópolis. In addition, oysters cultured in São Francisco do Sul were more uniformly distributed in the four size classes than those cultured in Florianópolis. The highest average values of wet flesh weight and shell weight were observed in São Francisco do Sul, whereas dry flesh weight did not differ between the sites. The estuary environment is more promising for the cultivation of oysters

Assessing the performance of the south american land data assimilation system version 2 (SALDAS-2) energy balance across diverse biomes

Understanding the exchange of energy between the surface and the atmosphere is important in view of the climate scenario. However, it becomes a challenging task due to a sparse network of observations. This study aims to improve the energy balance estimates for the Amazon, Cerrado, and Pampa biomes located in South America using the radiation and precipitation forcing obtained from the Clouds and the Earth’s Radiant Energy System (CERES) and the precipitation CPTEC/MERGE datasets. We employed three surface models—Noah-MP, Community Land Model (CLSM), and Integrated Biosphere Simulator (IBIS)—and conducted modeling experiments, termed South America Land Data Assimilation System (SALDAS-2). The results showed that SALDAS-2 radiation estimates had the smallest errors. Moreover, SALDAS-2 precipitation estimates were better than the Global Land Data Assimilation System (GLDAS) in the Cerrado (MBE = −0.16) and Pampa (MBE = −0.19). Noah-MP presented improvements compared with CLSM and IBIS in 100% of towers located in the Amazon. CLSM tends to overestimate the latent heat flux and underestimate the sensible heat flux in the Amazon. Noah-MP and Ensemble outperformed GLDAS in terms latent and sensible heat fluxes. The potential of SALDAS-2 should be emphasized to provide more accurate estimates of surface energy balance