Salomão Bueno

Pacing strategy determinants during a 10-km running time trial: contributions of perceived effort, physiological, and muscular parameters.

Abstract Bertuzzi, R, Lima-Silva, AE, Pires, FO, Damasceno, MV, Bueno, S, Pasqua, LA, and Bishop, DJ. Pacing strategy determinants during a 10-km running time trial: Contributions of perceived effort, physiological, and muscular parameters. J Strength Cond Res 28(6): 1688–1696, 2014—The purpose of this study was to identify the main determinants of the self-selected pacing strategy during a 10-km running time trial. Twenty eight male long-distance runners performed the following tests: (a) maximal incremental treadmill test, (b) economy running test, (c) maximum dynamic strength test, and (d) 10-km running time trial on an outdoor track. A stepwise multiple regression model was used to identify the contribution of rating of perceived exertion (RPE), physiological, and muscular parameters on the pacing strategy adopted by athletes. In the start phase (first 400 m), RPE accounted for 72% (p = 0.001) of the pacing variance. Peak treadmill speed (PTS) measured during a maximal incremental test explained 52% (p = 0.001) of the pacing variance during the middle phase (400–9,600 m), whereas maximal oxygen uptake and maximum dynamic strength accounted for additional 23% (p = 0.002) and 5% (p = 0.003), respectively. In the end phase (last 400 m), PTS accounted alone for 66% (p = 0.003) of the pacing variance. These data suggest that predictors of the pacing strategy during a 10-km running time trial have a transitional behavior from perceptive (start phase) to muscular and physiological factors (middle and end phases).

Bioenergetics and Neuromuscular Determinants of the Time to Exhaustion at Velocity Corresponding to V[Combining Dot Above]O2max in Recreational Long-Distance Runners

Abstract Bertuzzi, R, Bueno, S, Pasqua, LA, Acquesta, FM, Batista, MB, Roschel, H, Kiss, MAPDM, Serrão, JC, Tricoli, V, and Ugrinowitsch, C. Bioenergetics and neuromuscular determinants of the time to exhaustion at velocity corresponding to V[Combining Dot Above]O2max in recreational long-distance runners. J Strength Cond Res 26(8): 2096–2102, 2012—The purpose of this study was to investigate the main bioenergetics and neuromuscular determinants of the time to exhaustion (Tlim) at the velocity corresponding to maximal oxygen uptake in recreational long-distance runners. Twenty runners performed the following tests on 5 different days: (a) maximal incremental treadmill test, (b) 2 submaximal tests to determine running economy and vertical stiffness, (c) exhaustive test to measured the Tlim, (d) maximum dynamic strength test, and (e) muscle power production test. Aerobic and anaerobic energy contributions during the Tlim test were also estimated. The stepwise multiple regression method selected 3 independent variables to explain Tlim variance. Total energy production explained 84.1% of the shared variance (p = 0.001), whereas peak oxygen uptake (V[Combining Dot Above]O2peak) measured during Tlim and lower limb muscle power ability accounted for the additional 10% of the shared variance (p = 0.014). These data suggest that the total energy production, V[Combining Dot Above]O2peak, and lower limb muscle power ability are the main physiological and neuromuscular determinants of Tlim in recreational long-distance runners.

Strength-training with whole-body vibration in long-distance runners: a randomized trial.

A parallel group randomized trial was designed to analyze the impact of 6 weeks of strength training programs performed with or without whole-body vibration on muscular and endurance performance parameters in long-distance runners. 22 endurance runners were allocated into strength with whole-body vibration (n=8), without (n=8), and control (n=6) groups. Before and after the experimental period the subjects performed the following tests: a) maximum dynamic strength test, b) maximal incremental treadmill test, and c) time to exhaustion at velocity corresponding to maximal oxygen uptake. The fractions of the aerobic and anaerobic contribution in time to exhaustion test were also calculated. Both strength trained groups showed a similar increase in maximum dynamic strength (~18%). The aerobic contribution was enhanced for strength training group without whole-body vibration (~25%) after experimental period. No statistical differences were observed in any other variable. These results suggest that 6 weeks of strength training performed with or without whole-body vibration improve similarly the maximum dynamic strength in long-distance runners. In addition, both training modes studied had no deleterious effects on the traditional parameters of endurance performance, traditional strength training program results in increased aerobic contribution during high-intensity aerobic exercise.

GEDAE-LaB: A Free Software to Calculate the Energy System Contributions during Exercise.

Purpose The aim of the current study is to describe the functionality of free software developed for energy system contributions and energy expenditure calculation during exercise, namely GEDAE-LaB. Methods Eleven participants performed the following tests: 1) a maximal cycling incremental test to measure the ventilatory threshold and maximal oxygen uptake (V˙O2max); 2) a cycling workload constant test at moderate domain (90% ventilatory threshold); 3) a cycling workload constant test at severe domain (110% V˙O2max). Oxygen uptake and plasma lactate were measured during the tests. The contributions of the aerobic (AMET), anaerobic lactic (LAMET), and anaerobic alactic (ALMET) systems were calculated based on the oxygen uptake during exercise, the oxygen energy equivalents provided by lactate accumulation, and the fast component of excess post-exercise oxygen consumption, respectively. In order to assess the intra-investigator variation, four different investigators performed the analyses independently using GEDAE-LaB. A direct comparison with commercial software was also provided. Results All subjects completed 10 min of exercise at moderate domain, while the time to exhaustion at severe domain was 144 ± 65 s. The AMET, LAMET, and ALMET contributions during moderate domain were about 93, 2, and 5%, respectively. The AMET, LAMET, and ALMET contributions during severe domain were about 66, 21, and 13%, respectively. No statistical differences were found between the energy system contributions and energy expenditure obtained by GEDAE-LaB and commercial software for both moderate and severe domains (P > 0.05). The ICC revealed that these estimates were highly reliable among the four investigators for both moderate and severe domains (all ICC ≥ 0.94). Conclusion These findings suggest that GEDAE-LaB is a free software easily comprehended by users minimally familiarized with adopted procedures for calculations of energetic profile using oxygen uptake and lactate accumulation during exercise. By providing availability of the software and its source code we hope to facilitate future related research.

Influence of ACTN3 R577X polymorphism on ventilatory thresholds related to endurance performance

Abstract The purpose of this study was to verify the association between ACTN3 polymorphism and physiological parameters related to endurance performance. A total of 150 healthy male volunteers performed a maximal incremental running test to determine the speeds corresponding to ventilatory threshold (VT) and respiratory compensation point (RCP). Participants were genotyped and divided into terciles based on the analysed variables. Genotype frequencies were compared through χ2 test between lower and higher terciles, with the lowest or highest values of each analysed variable. ACTN3 XX genotype was over-represented in higher tercile for VT and RCP. Odds ratio also showed significantly higher chances of XX individuals to be in higher tercile compared to RR (7.3) and RR + RX (3.5) for VT and compared to RR genotype (8.1) and RR + RX (3.4) for RCP. Thus, XX individuals could attain the VT and RCP at higher speeds, suggesting that they are able to sustain higher running speeds in lower exercise intensity domains. It could result in higher lipid acids oxidation, saving muscle glycogen and delaying the fatigue during prolonged exercises, which could be the advantage mechanism of this genotype to endurance performance.

Is the COL5A1 rs12722 Gene Polymorphism Associated with Running Economy

The COL5A1 rs12722 polymorphism is considered to be a novel genetic marker for endurance running performance. It has been postulated that COL5A1 rs12722 may influence the elasticity of tendons and the energetic cost of running. To date, there are no experimental data in the literature supporting the relationship between range of motion, running economy, and the COL5A1 rs12722 gene polymorphism. Therefore, the main purpose of the current study was to analyze the influence of the COL5A1rs12722 polymorphism on running economy and range of motion. One hundred and fifty (n = 150) physically active young men performed the following tests: a) a maximal incremental treadmill test, b) two constant-speed running tests (10 km•h−1 and 12 km•h−1) to determine the running economy, and c) a sit-and-reach test to determine the range of motion. All of the subjects were genotyped for the COL5A1 rs12722 single-nucleotide polymorphism. The genotype frequencies were TT = 27.9%, CT = 55.8%, and CC = 16.3%. There were no significant differences between COL5A1 genotypes for running economy measured at 10 km•h−1 (p = 0.232) and 12 km•h−1 (p = 0.259). Similarly, there were no significant differences between COL5A1 genotypes for range of motion (p = 0.337). These findings suggest that the previous relationship reported between COL5A1 rs12722 genotypes and running endurance performance might not be mediated by the energetic cost of running.

The genetics of human running: ACTN3 polymorphism as an evolutionary tool improving the energy economy during locomotion

Abstract Background: Covering long distances was an important trait to human evolution and continues to be highlighted for health and athletic status. This ability is benefitted by a low cost of locomotion (CoL), meaning that the individuals who are able to expend less energy would be able to cover longer distances. The CoL has been shown to be influenced by distinct and even ‘opposite’ factors, such as physiological and muscular characteristics, which are genetically inherited. In this way, DNA alterations could be important determinants of the characteristics associated with the CoL. A polymorphism in the ACTN3 gene (R577X) has been related to physical performance, associating the X allele with endurance and the R allele with strength/power abilities. Aim: To investigate the influence of ACTN3 genotypes on the CoL. Subjects and methods: One hundred and fifty healthy male individuals performed two constant speed tests (at 10 and 12 km/h) to determine the CoL. Results: Interestingly, the results showed that heterozygous individuals (RX genotype) presented significantly lower CoL compared to RR and XX individuals. Conclusions: It is argued that RX genotype might generate an intermediate strength-to-endurance phenotype, leading to a better phenotypic profile for energy economy during running and, consequently, for long-term locomotion.

Association between Ventilatory Thresholds Related to Aerobic Fitness and MCT1 A1470T Polymorphism

The purpose of this study was to verify the association between MCT1 polymorphism with physiological parameters related to aerobic fitness. A hundred fifty healthy male volunteers performed a maximal incremental running test to determine the speeds corresponding to Ventilatory Threshold (VT) and Respiratory Compensation Point (RCP). Participants were genotyped and divided in terciles based on the analyzed variables. Genotype frequencies were compared through chi-square test between lower (LT) and higher terciles (HT), with the lowest or highest values of each analyzed variable. MCT1 TT genotype was overrepresented in HT only for VT and showed a significantly higher odds ratio of belong to HT for VT compared only to AA (5.1). These results suggest that TT individuals could attain the VT and RCP at higher speeds, being able to sustain higher running speeds in lower exercise intensity domains. In other words, it is possible that individuals carrying the MCT1 TT genotype might run at higher speeds with lower fatigue signals, mimicking an inner aerobic fitness adaptation.

Risco de fadiga prematura, percepção subjetiva de esforço e estratégia de prova durante uma corrida de 10 km

O objetivo do estudo foi verificar as modificacoes na estrategia de prova frente as alteracoes do risco de fadiga prematura e da percepcao subjetiva de esforco (PSE) em corredores durante uma corrida de 10 km. Participaram do estudo 55 corredores com tempo nos 10 km de 41:39 ± 3:52 min:s. A estrategia de prova e a PSE foram avaliadas a cada quilometro. O risco de fadiga prematura foi determinado pelo produto entre a PSE e a distância restante de prova e a estrategia de prova foi determinada pela curva da velocidade e distância. A ANOVA de um caminho para medidas repetidas foi utilizada para determinar as diferencas na velocidade, PSE e risco de fadiga a cada quilometro e entre a velocidade a cada quilometro e a velocidade media da prova. O coeficiente de correlacao de Pearson foi calculado entre a PSE e o risco de fadiga prematura com a velocidade. A velocidade do primeiro quilometro foi 8,1% maior do que a media (p ≤ 0,001). A velocidade diminuiu gradualmente ao longo da prova, ocorrendo um novo aumento no decimo quilometro. A PSE aumentou linearmente ao longo da prova e o risco de fadiga diminuiu significantemente apos o terceiro quilometro. Houve forte correlacao negativa entre a PSE e a velocidade desenvolvida durante a prova (r = -0,80; p = 0,006). Foi observada uma correlacao moderada negativa entre o risco de fadiga prematura e a velocidade (r = -0,57; p = 0,04). Com isso, os achados do presente estudo sugerem que a PSE parece ter importante papel sobre os ajustes da velocidade ao longo da prova, sendo que o aumento da velocidade observado no ultimo quilometro pode estar associado ao baixo risco de fadiga prematura.

É possível determinar a economia de corrida através do teste progressivo até a exaustão

O objetivo do presente estudo foi verificar a possibilidade de se estimar a economia de corrida (EC) a partir do coeficiente angular gerado pela relacao VO2 vs. intensidade de testes progressivos ate a exaustao (ECINCLINA). Para tanto, 16 corredores de provas de longa duracao (idade 32 ± 7 anos, massa corporal 70,0 ± 6,7 kg, estatura 173,3 ± 5,0 cm, O2max 57,9 ± 5,8 ml·kg-1·min-1) foram submetidos a um teste incremental e a dois testes de cargas constantes (12 km·h-1 e a intensidade de 90% do segundo limiar ventilatorio) para a mensuracao da EC. Foram detectadas correlacoes fracas entre o ECINCLINA e a EC estabelecida a 12 km·h-1 (r = 0,49; p = 0,054) e na intensidade de 90% do segundo limiar ventilatorio (r = 0,55; p = 0,027). Alem disso, o ECINCLINA tambem estava negativamente correlacionado com a concentracao sanguinea de lactato (r = -0,75; p = 0,001) e a razao de troca respiratoria (r = -0,80; p < 0,001) mensuradas ao final no teste progressivo. Portanto, esses achados sugerem que, embora a sua aplicacao para determinar a EC seja limitada, o ECINCLINA pode ser um parâmetro alternativo empregado para o diagnostico da aptidao de corredores de provas de longa duracao devido a sua relacao com o metabolismo anaerobio.