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

Complex network models reveal correlations among network metrics, exercise intensity and role of body changes in the fatigue process

The article of record as published may be located at https://doi.org/10.1038/srep10489The aims of the present study were analyze the fatigue process at distinct intensity efforts and to investigate its occurrence as interactions at distinct body changes during exercise, using complex network models. For this, participants were submitted to four different running intensities until exhaustion, accomplished in a non-motorized treadmill using a tethered system. The intensities were selected according to critical power model. Mechanical (force, peak power, mean power, velocity and work) and physiological related parameters (heart rate, blood lactate, time until peak blood lactate concentration (lactate time), lean mass, anaerobic and aerobic capacities) and IPAQ score were obtained during exercises and it was used to construction of four complex network models. Such models have both, theoretical and mathematical value, and enables us to perceive new insights that go beyond conventional analysis. From these, we ranked the influences of each node at the fatigue process. Our results shows that nodes, links and network metrics are sensibility according to increase of efforts intensities, been the velocity a key factor to exercise maintenance at models/intensities 1 and 2 (higher time efforts) and force and power at models 3 and 4, highlighting mechanical variables in the exhaustion occurrence and even training prescription applications

Computational and Complex Network Modeling for Analysis of Sprinter Athletes’ Performance in Track Field Tests

The article of record as published may be located at https://doi.org/10.3389/fphys.2018.00843Sports and exercise today are popular for both amateurs and athletes. However, we continue to seek the best ways to analyze best athlete performances and develop specific tools that may help scientists and people in general to analyze athletic achievement. Standard statistics and cause-and-effect research, when applied in isolation, typically do not answer most scientific questions. The human body is a complex holistic system exchanging data during activities, as has been shown in the emerging field of network physiology. However, the literature lacks studies regarding sports performance, running, exercise, and more specifically, sprinter athletes analyzed mathematically through complex network modeling. Here, we propose complex models to jointly analyze distinct tests and variables from track sprinter athletes in an untargeted manner. Through complex propositions, we have incorporated mathematical and computational modeling to analyze anthropometric, biomechanics, and physiological interactions in running exercise conditions. Exercise testing associated with complex network and mathematical outputs make it possible to identify which responses may be critical during running. The physiological basis, aerobic, and biomechanics variables together may play a crucial role in performance. Coaches, trainers, and runners can focus on improving specific outputs that together help toward individuals’ goals. Moreover, our type of analysis can inspire the study and analysis of other complex sport scenarios

Adaptation of invasive and non-invasive protocols to aerobic and anaerobic specific evaluation in female basketball players

OBJECTIVE: To adapted the critical velocity (CV), RAST test and lactate minimum (LM) to evaluation of female basketball players. METHODS: Twelve well-trained female basketball players (19 ± 1yrs) were submitted to four intensities running (10 - 14 km/h) at shuttle exercise until exhaustion, applied on alternate days. The linear model 'velocity vs. 1/tlim' was adopted to determine the aerobic (CV) and anaerobic (CCA) parameters. The lactate minimum test consisted of two phases: 1) hiperlactatemia induction using the RAST test and 2) incremental test composed by five shuttle run (20-m) at 7, 8, 9, 10, and 12 km/h. Blood samples were collected at the end of each stage. RESULTS: The velocity (vLM) and blood lactate concentration at LM were obtained by two polynomial adjustments: lactate vs. intensity (LM1) and lactate vs. time (LM2). ANOVA one-way, Student t-test and Pearson correlation were used for statistical analysis. The CV was obtained at 10.3 ± 0.2 km/h and the CCA estimated at 73.0 ± 3.4 m. The RAST was capable to induce the hiperlactatemia and to determine the Pmax (3.6 ± 0.2 W/kg), Pmed (2.8 ± 0.1 W/kg), Pmin (2.3 ± 0.1 W/kg) and FI (30 ± 3%). The vLM1 and vLM2 were obtained, respectively, at 9.47 ±0.13 km/h and 9.8 ± 0.13 km/h, and CV was higher than vLM1. CONCLUSION: The results suggest that the non-invasive model can be used to determine the aerobic and anaerobic parameters. Furthermore, the LM test adapted to basketball using RAST and progressive phase was effective to evaluate female athletes considering the specificity of modality, with high success rates observed in polynomial adjustment 'lactate vs. time' (LM2).OBJETIVO: Adaptar os protocolos de velocidade crítica (Vcrit), RAST Test e Lactato Mínimo (LM) à especificidade do basquetebol feminino. MÉTODOS: Doze basquetebolistas bem treinadas (19 ± 1 anos) foram avaliadas pelo modelo velocidade crítica, composto por quatro intensidades (10,8, 12,0, 13,0, 14,5 km/h) de corridas vai-vem até exaustão, aplicadas em dias alternados. O modelo linear 'velocidade versus 1/tlim' foi adotado para determinação de parâmetros aeróbio (Vcrit) e anaeróbio (CCA). O LM foi composto por duas fases: 1) indução hiperlactacidêmica, caracterizada pelo RAST adaptado, e 2) fase progressiva, composta por cinco estágios de 3 minutos em corridas vai-vem de 20 m (7 a 12km/h), com coletas de sangue ao final de cada estágio. RESULTADOS: A velocidade (vLM) e a concentração do lactato mínimo foram obtidas pelos ajustes polinomiais 'lactato versus intensidade' (LM1) e 'lactato versus tempo' (LM2). A ANOVA one-way, teste t-Student e correlação de Pearson foram utilizados na análise estatística. A Vcrit foi obtida a 10,3 ± 0,2 km/h e a CCA estimada em 73,0 ± 3,4 m. O RAST foi capaz de induzir a hiperlactacidemia e determinar potências máxima (3,6 ± 0,2 W/kg), média (2,8 ± 0,1 W/kg), mínima (2,3 ± 0,1W/kg) e o índice de fadiga (30 ± 3%). A vLM1 e vLM2 foram obtidas, respectivamente, a 9,47 ± 0,13 e 9,8 ± 0,13km/h, sendo a vLM1 menor que a Vcrit. CONCLUSÕES: Os resultados sugerem que o modelo específico não invasivo pode ser utilizado para determinar parâmetros aeróbios e anaeróbios de basquetebolistas e, assim como em outras modalidades, a Vcrit superestima as intensidades de LM. Além disso, a adaptação do LM ao basquetebol feminino utilizando o RAST e a fase progressiva em exercício vai-vem foi efetiva para avaliar as atletas respeitando a especificidade da modalidade, com elevado percentual de sucesso no ajuste polinomial 'lactato versus tempo'.17117

MCT1 and MCT4 kinetic of mRNA expression in different tissues after aerobic exercise at maximal lactate steady state workload

We evaluate the mRNA expression of monocarboxylate transporters 1 and 4 (MCT1 and MCT4) in skeletal muscle (soleus, red and white gastrocnemius), heart and liver tissues in mice submitted to a single bout of swimming exercise at the maximal lactate steady state workload (MLSSw). After 72 h of MLSS test, the animals were submitted to a swimming exercise session for 25 min at individual MLSSw. Tissues and muscle samples were obtained at rest (control, n=5), immediately (n=5), 5 h (n=5) and 10 h (n=5) after exercise for determination of the MCT1 and MCT4 mRNA expression (RT-PCR). The MCT1 mRNA expression in liver increased after 10 h in relation to the control, immediate and 5 h groups, but the MCT4 remained unchanged. The MCT1 mRNA expression in heart increased by 31 % after 10 h when compared to immediate, but no differences were observed in relation to the control group. No significant differences were observed for red gastrocnemius in MCT1 and MCT4 mRNA expression. However, white gastrocnemius increased MCT1 mRNA expression immediately when compared to rest, 5 and 10 h test groups. In soleus muscle, the MCT1 mRNA expression increased immediately, 5 and 10 h after exercise when compared to the control. In relation to MCT4 mRNA expression, the soleus increased immediately and 10 h after acute exercise when compared to the control group. The soleus, liver and heart were the main tissues that showed improved the MCT1 mRNA expression, indicating its important role in controlling MLSS concentration in mice.644513522CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informaçãosem informação04/06643-1FAP-UNIME

Characterization and reproducibility of canoe slalom simulated races: physiological, technical and performance analysis

The aims of this study were to characterise and test the reproducibility of canoe slalom race simulations performed on two different days, analysing the physiological, technical and performance responses characteristic of the sport. Six high-performance male canoe slalom K1 athletes (age 17±2yrs) underwent two race simulations with an interval of 72 hours. The artificial course consisted of twelve gates. Each simulation was analysed the runtime, distance travelled, mean velocity; images were captured by the digital camera (JVC) and determined quantitative variables. Heart monitors (Polar, RS800x model) were used to record heart rate during race simulations and recovery; data were stored every 5 s, to determine the blood lactate concentration ([Lac]), blood samples were collected from the earlobe at rest and after 1, 3, 5, 7 and 9 min of race simulation (recovery). Tests of normality (Shapiro Wilk) and variance (Levene) were applied. The variables were compared using paired t-tests. Intraclass coefficient correlation (ICC) and Pearson product moment were used for relationship. In all cases, the level of significance was pre-fixed at 5%. Differences between the first and second simulations could not be noticed. Another important indicator was the high correlation found between the runtime (ICC=0.71), distance travelled (ICC=0.77), mean velocity (ICC=0.80) and total number of paddles (ICC=0.79). The lactate levels on minutes 3, 5, 7 and 9 also pointed towards strong correlations (ICC=0.88, ICC=0.90, ICC=0.95 and ICC=0.90 respectively), which may indicate that the adopted simulation model seems to be practicable and of great value to canoe slalom evaluations.We would like to thank FAPESP and CNPq for providing financial support

Is the aerobic power a delimitating factor for performance on canoe slalom? An analysis of Olympic Slovak canoe slalom medalists and non-Olympics since Beijing 2008 to Rio 2016

Information regarding the aerobic power on canoe slalom performance is scares. Moreover, the comparison of maximum oxygen uptake (VO2max) via specific and non-specific ergometer for slalom kayakers may improve training prescription and controlling over Olympic cycles. Lastly, it is still unknown to what extent the VO2max delimitate the high performance in this sport. To test this perspective, a highly qualified sample is desired. In overall statistics, Slovakian athletes gathered 14 Olympic medals over the last sixteen years. Therefore, the main aim of this study is to compare the aerobic power of Olympic medallists and Non-Olympic Slovakian kayakers via specific and non-specific evaluations from Beijing 2008 to Rio 2016 Summer Olympic Games. Forty-two male canoe slalom athletes from Slovak national team were evaluated between the years 2006 and 2016. Slovakian athletes were tested for specific (i.e. paddling ergometer) and non-specific (i.e. treadmill) incremental protocols for VO2max determination. Over the last three Summer Olympic Games, the VO2max of Slovakian Olympic medallists was consistently lower than most of the Slovakian team. Moreover, disregarding the medallist characteristic or the moment, Slovakian kayakers presented higher VO2max on treadmill (57.7±6.8 mL.kg-1.min-1) when compared to paddle ergometer (46.9±6.5 mL.kg-1.min-1) (p=0.000; ES=1.6). Based on the collected data over the last ten years, we suggest that although aerobic power may play a relevant and indirect role on performance of slalom kayakers, does not delimitate the high performance in this sport.This study was partly funded by the Ministry of Education, Science, Research and Sport of the Slovak Republic, grant no. 1/0058/16

Computational and Complex Network Modeling for Analysis of Sprinter Athletes’ Performance in Track Field Tests

Sports and exercise today are popular for both amateurs and athletes. However, we continue to seek the best ways to analyze best athlete performances and develop specific tools that may help scientists and people in general to analyze athletic achievement. Standard statistics and cause-and-effect research, when applied in isolation, typically do not answer most scientific questions. The human body is a complex holistic system exchanging data during activities, as has been shown in the emerging field of network physiology. However, the literature lacks studies regarding sports performance, running, exercise, and more specifically, sprinter athletes analyzed mathematically through complex network modeling. Here, we propose complex models to jointly analyze distinct tests and variables from track sprinter athletes in an untargeted manner. Through complex propositions, we have incorporated mathematical and computational modeling to analyze anthropometric, biomechanics, and physiological interactions in running exercise conditions. Exercise testing associated with complex network and mathematical outputs make it possible to identify which responses may be critical during running. The physiological basis, aerobic, and biomechanics variables together may play a crucial role in performance. Coaches, trainers, and runners can focus on improving specific outputs that together help toward individuals’ goals. Moreover, our type of analysis can inspire the study and analysis of other complex sport scenarios