Mauro Alexandre Benites Batista

Influence of training background on jumping height.

The aim of this study was to compare the pattern of force production and center of mass kinematics in maximal vertical jump performance between power athletes, recreational bodybuilders, and physically active subjects. Twenty-seven healthy male subjects (age: 24.5 ± 4.3 years, height: 178.7 ± 15.2 cm, and weight: 81.9 ± 12.7 kg) with distinct training backgrounds were divided into 3 groups: power track athletes (PT, n = 10) with international experience, recreational bodybuilders (BB, n = 7) with at least 2 years of training experience, and physically active subjects (PA, n = 10). Subjects performed a 1 repetition maximum (1RM) leg press test and 5 countermovement jumps with no instructions regarding jumping technique. The power-trained group jumped significantly higher (p > 0.05) than the BB and PA groups (0.40 ± 0.05, 0.31 ± 0.04, and 0.30 ± 0.05, respectively). The difference in jumping height was not produced by higher rates of force development (RFD) and shorter center of mass (CM) displacement. Instead, the PT group had greater CM excursion (p > 0.05) than the other groups. The PT and BB groups had a high correlation between jumping height and 1RM test (r = 0.93 and r = 0.89, p > 0.05, respectively). In conclusion, maximum strength seems to be important for jumping height, but RFD does not seem relevant to achieve maximum jumping heights. High RFD jumps should be performed during training only when sport skills have a time constraint for force application.

Intermittent exercise as a conditioning activity to induce postactivation potentiation

Postactivation potentiation (PAP) is defined as a short-term increase in voluntary muscle activation following a previous conditioning activity (CA). Controversy about PAP is mostly attributed to the characteristics of the CA and the training status of the subjects. While some studies have found that PAP can be induced by series of 5–10 second maximal voluntary isometric contractions or near maximal dynamic contractions (e.g., 3–5 repetition maximum), others have failed to do so. On the other hand, some studies suggest that intermittent contractions can also induce PAP. However, even though PAP was observed, its duration was not taken into account, leaving ground for further investigations. The purpose of this study was threefold: (a) to verify if PAP can progressively enhance performance of voluntary actions throughout a set of intermittent contractions; (b) to verify PAP duration when induced by an intermittent contractions protocol; and (c) to verify if PAP effects were reproducible in different sessions when induced by intermittent contractions. Ten physically active men, not engaged in strength training, underwent 5 randomized experimental sessions, during which they performed a set of 10 unilateral knee extensions (KE) (1 every 30 seconds) at 60°·s-1 in an isokinetic dynamometer. Peak torque was evaluated over the 10 unilateral KE and at the randomized intervals of 4, 6, 8, 10, and 12 minutes post CA. Peak torque was potentiated 1.3 (±0.79) N·m per unilateral KE, and the potentiation effect persisted for 12 minutes after the last contraction. These findings were reproduced in all 5 experimental sessions. Thus, intermittent conditioning activities seem to be an effective way to produce PAP. However, these activities should be tested in a more real world situation to verify the applicability as a warm-up routine.

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.

Efeito da familiarização na estabilização dos valores de 1RM para homens e mulheres

The purpose of this study was to determine the number of familiarization sessions for stabilizing the load of one repetition maximum (1RM) tests on the squat exercise in men and women. Eight men (25 ± 4 years) and eight women (20 ± 1 years) underwent five experimental sessions. ANOVA and Bland-Altman plotting were used to compare the 1RM load between the sessions (p<0.05). The stabilization of load occurred at the fourth session for men and at the third session for women, with significantly increased in relative and absolute strength from the first to the fourth (17kg and 19%) and from the first to the third (9kg and 14%) session, respectively. However, relative strength did not differ significantly between genders. According to our results, individuals not experienced with strength training can reach high reliability in the 1RM test in the squat exercise, after performing three or four familiarizations sessions.

Effects of Strength Training Associated With Whole-Body Vibration Training on Running Economy and Vertical Stiffness

Abstract Roschel, H, Barroso, R, Tricoli, V, Batista, MAB, Acquesta, FM, Serrão, JC, and Ugrinowitsch, C. Effects of strength training associated with whole-body vibration training on running economy and vertical stiffness. J Strength Cond Res 29(8): 2215–2220, 2015—Running economy (RE) is defined as the energy cost to maintain a submaximal running velocity and seems to be affected by individuals neuromuscular characteristics, such as stiffness level. Both resistance training (RT) and whole-body vibration training added to RT (WBV + RT) have been shown to influence those characteristics. Thus, it is conceivable that RT and WBV + RT could also affect RE. The objective of this study was to investigate if a 6-week training period of RT and WBV + RT influences RE and vertical stiffness (VS). Fifteen recreational runners were divided into RT or WBV + RT groups. Running economy, VS, and lower-limb maximum dynamic strength (1 repetition maximum [1RM] half-squat) were assessed before and after the 6-week training period. There was a main time effect for 1RM, but no other statistically significant difference was observed. Neither conventional RT nor RT performed on a WBV platform improved VS and RE in recreational long distance runners. It is possible that movement velocity was rather low, and utilization of stretch-shortening cycle might have been compromised, impairing any expected improvement in RE.

Do whole-body vibration exercise and resistance exercise modify concentrations of salivary cortisol and immunoglobulin A?

A single bout of resistance exercise (RE) induces hormonal and immune responses, playing an important role in a long-term adaptive process. Whole-body vibration (WBV) has also been shown to affect hormonal responses. Evidence suggests that combining WBV with RE may amplify hormonal and immune responses due to the increased neuromuscular load. Therefore, the aim of this study was to evaluate salivary cortisol (Scortisol) and salivary IgA (SIgA) concentrations following a RE session combined or not with WBV. Nine university students (22.9 ± 5.1 years, 175.8 ± 5.2 cm, and 69.2 ± 7.3 kg) performed five sets of squat exercise (70% one-repetition-maximum) combined (R+V30) or not (R) with WBV at 30 Hz. Saliva samples were obtained before and after exercise. Subjects also rated their effort according to the Borg CR-10 scale (RPE). Data were analyzed by a mixed model. RPE was higher after R+V30 (8.3 ± 0.7) compared to R (6.2 ± 0.7). However, Scortisol (pre: 10.6 ± 7.6 and 11.7 ± 7.6, post: 8.3 ± 6.3 and 10.2 ± 7.2 ng/mL for R and R+V30, respectively) and SIgA concentrations (pre: 98.3 ± 22.6 and 116.1 ± 51.2, post: 116.6 ± 64.7 and 143.6 ± 80.5 µg/mL for R and R+V30, respectively) were unaffected. No significant correlations were observed between Scortisol and RPE (r = 0.45, P = 0.22; r = 0.30, P = 0.42, for R and R+V30, respectively). On the basis of these data, neither protocol modified salivary cortisol or IgA, although RPE was higher after R+V30 than R.

O treinamento de força com e sem o uso da plataforma vibratória é capaz de modular a variabilidade da frequência cardíaca em repouso

The current research compared resting heart rate variability (VFC) before and after 10 weeks of strength training in groups that used and did not use a vibration platform. Seventeen healthy men were divided into conventional strength training (TF) or strength training using a vibration platform with a frequency of 30 Hz (TF+V30) training groups. One repetition maximum load (1-RM) on half squat exercise and VFC measurements were determined pre- and post-training program. Both groups had improved 1-RM load after the program (15.1% in TF group and 16.4% in TF+V30 group), although this increase was changed in the same extent for the two groups and there was no difference in 1-RM load between groups pre- and post-training program. No significant difference was observed in resting VFC measurements between groups pre and post-training program, however the magnitude of the effect size was moderated (ES = 0.50-0.80) for some variables (R-R interval, standard deviation of all R-R interval - SDNN, RMSSD, log-transformed of low frequency - InLF, and log-transformed of high frequency - InHF) in TF+V30 group. It was concluded that 10 weeks of strength training program with or without the vibration platform provided similar increase in 1-RM load in both groups, and although some evidences in this study indicate that vibration can increase vagal activity analyzed by ES, in neither groups the strength training was able to change VFC significantly.

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.