Nilo Massaru Okuno

Familiarization indexes in sessions of 1-RM tests in adult women.

Soares-Caldeira, LF, Ritti-Dias, RM, Okuno, NM, Cyrino, ES, Gurjão, ALD, and Ploutz-Snyder, LL. Familiarization indexes in sessions of 1-RM tests in adult women. J Strength Cond Res 23(7): 2039-2045, 2009-The objective of this study was to evaluate the familiarization to the 1-repetition maximum (1-RM) test in adult women with previous experience in resistance training and to compare the statistical methods to analyze familiarization. Twenty-seven women, with previous experience in resistance training but detrained for 6 months, participated in the study (21.6 ± 2.5 years; 59.1 ± 6.7 kg; 1.65 ± 0.04 m; 21.8 ± 2.4 kg/m2). The 1-RM test was used to verify the strength levels in 3 exercises: bench press, squat, and arm curl. Five 1-RM tests sessions were performed in distinct days. Analysis of variance (ANOVA) for repeated measures, intraclass correlation coefficient (ICC), and Bland-Altman plotting procedures were used to compare the 1-RM load between the familiarization sessions. The significance assumed was p < 0.05. All exercises presented good ICC between 1-RM familiarization sessions (0.97-0.98). However, there were significant increases in 1-RM load among the 5 sessions of 1-RM tests in the bench press (+5.7%), squat (+5.4%), and arm curl (+11.1%). In addition, there were different responses according to the statistical analyses used (ANOVA, higher 1-RM strength, and Bland-Altman plotting). The results of the present study suggest that familiarization sessions are important for an accurate assessment of 1-RM load even in subjects with previous experience in resistance training.

Critical power can be estimated from nonexhaustive tests based on rating of perceived exertion responses

The purpose of this study was to evaluate a novel procedure, based on the perceived exertion threshold (PET) concept, involving non-exhaustive tests (PET14-17) to estimate critical power (CP), as well as to examine the reproducibility of these indices. Twenty young men performed 2 trials (Trial 1 and Trial 2) of 4 exhaustive predictive tests to estimate CP, PET, and PET14-17. The slope coefficients of the regression lines corresponding to the ratings of perceived exertion (RPE) versus time relationship (y axis) obtained during the predictive tests were plotted against the power outputs (x axis) to estimate PET. PET was calculated as the intersection point of the regression line in the power axis. The 14-17 RPE range of each predictive test was modeled using the same mathematical procedures used to estimate PET14-17. CP was derived from the power-time hyperbolic equation. Analysis of variance revealed no significant differences among CP (189-194 W), PET (190-191 W) and PET14-17, (191-195 W). The correlations between CP and PET (r = 0.87), CP and PET14-17 (r = 0.89), and PET and PET14-17 (r = 0.88) were all strong. Additionally, the bias ± limits of agreement when plotting CP and PET was -2.16 ± 31.60 W, and -5.70 ± 31.21 W when comparing CP and PET14-17. Relatively high reproducibility levels of CP (ICC = 0.96), PET (ICC = 0.85) and PET14-17 (ICC = 0.83) were recorded in the test-retest fashion. It can be concluded that the PET14-17 can be utilized with relatively high accuracy and reproducibility to estimate CP without causing exhaustion in the subjects.

Postactivation Potentiation on Repeated-Sprint Ability in Elite Handball Players

Abstract Okuno, NM, Tricoli, V, Silva, SBC, Bertuzzi, R, Moreira, A, and Kiss, MAPDM. Postactivation potentiation on repeated-sprint ability in elite handball players. J Strength Cond Res 27(3): 662–668, 2013—The aim of this study was to analyze the changes on repeated-sprint ability (RSA) performance after heavy load exercise in elite handball players. Twelve subjects were submitted to the following experimental sessions: (a) 1-repetition maximum (1RM) test on the half squat exercise, (b) RSA test (control condition), and (c) RSA with a conditioning activity on the same exercise as 1RM test (experimental condition). The conditioning activity comprised 1 set of 5 × 50% 1RM, 1 set of 3 × 70% 1RM, and 5 sets of 1 × 90% 1RM. A significant improvement in the best sprint time (RSAbest) and mean sprint time (RSAmean) was observed with the conditioning activity (RSAbest = 5.74 ± 0.16 seconds; RSAmean = 5.99 ± 0.19 seconds) when compared with the situation without the conditioning activity (RSAbest = 5.82 ± 0.15 seconds; RSAmean = 6.06 ± 0.18 seconds; p < 0.01) with a moderate (Cohens d = −0.54) and small effect (Cohens d = −0.41) to RSAbest and RSAmean, respectively. Therefore, the findings of this study demonstrated that prior heavy load exercise can be used to improve the RSA performance, however, with a small to moderate magnitude of change.

Construct and concurrent validation of OMNI-Kayak rating of Perceived Exertion Scale.

This study tested the concurrent and construct validity of a newly developed OMNI–Kayak Scale, testing 8 male kayakers who performed a flatwater load-incremented “shuttle” test over a 500-m course and 3 estimation-production trials over a 1,000-m course. Velocity, blood lactate concentration, heart rate, and rating of perceived exertion (RPE), using the OMNI–Kayak RPE Scale and the Borg 6–20 Scale were recorded. OMNI–Kayak Scale RPE was highly correlated with velocity, the Borg 6–20 Scale RPE, blood lactate, and heart rate for both load-incremented test (rs = .87–.96), and estimation trials (rs = .75–.90). There were no significant differences among velocities, heart rate and blood lactate concentration between estimation and production trials. The OMNI–Kayak RPE Scale showed concurrent and construct validity in assessing perception of effort in flatwater kayaking and is a valid tool for self-regulation of exercise intensity.

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.

Cardiac autonomic recovery after a single session of resistance exercise with and without vascular occlusion.

Abstract Okuno, NM, Pedro, RE, Leicht, AS, de Paula Ramos, S, and Nakamura, FY. Cardiac autonomic recovery after a single session of resistance exercise with and without vascular occlusion. J Strength Cond Res 28(4): 1143–1150, 2014—The aim of this study was to investigate the heart rate variability (HRV) after resistance training with and without vascular occlusion. It was hypothesized that low intensity (LI) with vascular occlusion (LIO) would elicit comparable postexercise HRV responses with that of high intensity (HI) without vascular occlusion. Nine subjects undertook 4 experimental sessions of leg press exercise on different days: (a) 1 repetition maximum (1RM) test, (b) 4 sets of 8 repetitions + 1 set until exhaustion at 80% of 1RM without vascular occlusion (HI), (c) 4 sets of 16 repetitions + 1 set until exhaustion at 40% of 1RM with vascular occlusion (LIO), and (d) 4 sets of 16 repetitions + 1 set with the number of repetitions equal to the last set of LIO but at 40% of 1RM without vascular occlusion (LI). Heart rate variability was analyzed 10 minutes, 20 minutes, 30 minutes, 1 hour, 5 hours, and 24 hours after the HI, LIO, and LI sessions. The HI session increased the heart rate (HR) and reduced the root mean square of the successive difference of R-R intervals (RMSSD) and log-transformed high-frequency (lnHF) power during prolonged recovery (HR = 5 hours; RMSSD = 30 minutes; lnHF = 1 hour) at a greater magnitude when compared with LIO and LI. Despite the same intensity of exercise for LIO and LI, the occlusion delayed the recovery of HR and HRV variables. Postexercise blood lactate concentration was moderate to strongly correlated with peak HR (r = 0.87), RMSSD (r = −0.64), and lnHF (r = −0.68). This study has demonstrated that LIO was able to reduce cardiac autonomic stress when compared with HI.

Physiological and Perceived Exertion Responses at Intermittent Critical Power and Intermittent Maximal Lactate Steady State

Okuno, NM, Perandini, LAB, Bishop, D, Simões, HG, Pereira, G, Berthoin, S, Kokubun, E, and Nakamura, FY. Physiological and perceived exertion responses at intermittent critical power and intermittent maximal lactate steady state. J Strength Cond Res 25(7): 2053-2058, 2011—The aim of this study was to compare the power outputs of the intermittent critical power (CPi) with the intermittent maximal lactate steady state (MLSSi) and to compare the physiological and perceptual responses exercising at CPi and MLSSi. Ten subjects performed intermittent trials on a cycle ergometer to determine CPi and MLSSi using 30:30 seconds of effort and pause. The oxygen uptake (&OV0312;o2), heart rate (HR), blood lactate concentration ([Lac]), and rating of perceived exertion (RPE) responses were compared during 30-minute cycling at CPi and MLSSi. The CPi (267 ± 45 W) was similar to MLSSi (254 ± 39 W), and they were correlated (r = 0.88; p < 0.05). The &OV0312;o2 and HR responses stabilized throughout exercising at CPi (2.52 ± 0.52 L·min−1; 156 ± 8 b·min−1) and MLSSi (2.41 ± 0.32 L·min−1; 152 ± 10 b·min−1). These physiological variables were similar between conditions. However, the [Lac] and RPE were higher from the middle to the end of exercise duration at CPi ([Lac] = 6.9 ± 2.6 mM; RPE = 17.1 ± 2.1 a.u.) compared to MLSSi ([Lac] = 5.1 ± 0.9 mM; RPE = 15.7 ± 1.8 a.u.). Therefore, CPi intensity determined from 30:30 seconds of effort and rest periods on a cycle ergometer is equivalent to the MLSSi, and there is a physiological steady state throughout both exercise intensities, although the [Lac] and RPE responses at CPi are higher than at MLSSi. Thus, the CPi and MLSSi may be used as tools for intermittent training evaluation and prescription.

Effects of light-emitting diode irradiation on time to exhaustion at maximal aerobic speed

High-intensity exercises promote an increase in physiological variables until exhaustion and induce fatigue, leading to functional impairments and decreased performance [1, 2]. Thus, the skeletal muscles can play an important role in this type of exercise, mainly, through their ability to regulate the energy metabolism and ion homeostasis, reducing the fatigue process and optimizing performance [3, 4]. Several studies have sought strategies to reduce skeletal muscle fatigue and muscle damage and improve exercise performance [5–7]. A relatively recent technique that has aroused interest in an attempt to reduce fatigue and improve skeletal muscle recovery is photobiomodulation. Photobiomodulation is a technique performed by low-level laser [8] or light-emitting diode (LED) equipment [9] before or after musc le e f fo r t s . Some resea rche rs have shown tha t photobiomodulation increased performance in resistance exercise, improving the number of repetitions, strength, and maximal capacity for torque generation [9–11]. Likewise, photobiomodulation has been used to improve performance in running. De Marchi et al. [12] showed an increase on time to exhaustion (Tlim) after application of low-level laser therapy (LLLT) in an incremental test when compared to a placebo condition. In addition, the effectiveness of photobiomodulation has been observed when applied during exercise; Paolillo et al. [13] observed an increase on Tlim in submaximal constant load exercise. Additionally, Ferraresi et al. [14] observed an improvement on Tlim with decreased muscle damage and blood lactate concentration after applying LED irradiation prior to the high-intensity constant load exercise. However, the Ferraresi et al. [14] study analyzed the LED irradiation effect only in a single elite runner, which could present high bias, such as individual response and inter-day variability, in addition to which the authors did not use statistical analysis to strengthen their results. Furthermore, Thomas et al. [15] stated that fatigue in highintensity exercise is more dependent on peripheral factors (e.g., distinct physiological responses and disruption to intramuscular homeostasis). Therefore, the local application of LED irradiation could be an important strategy to improve performance. Moreover, considering that photobiomodulation stimulates mitochondrial activity [16, 17], it is supposed that there is a lower physiological demand during exercise, such as heart rate (HR) response, improving the exercise performance. Thus, the aim of this study was to verify the effects of LED irradiation on Tlim and HR response at maximum aerobic speed (MAS).

Effects of 16 Weeks of Concurrent Training on Resting Heart Rate Variability and Cardiorespiratory Fitness in People Living With HIV/AIDS Using Antiretroviral Therapy: A Randomized Clinical Trial.

Abstract Pedro, RE, Guariglia, DA, Okuno, NM, Deminice, R, Peres, SB, and Moraes, SMF. Effects of 16 weeks of concurrent training on resting heart rate variability and cardiorespiratory fitness in people living with HIV/AIDS using antiretroviral therapy: a randomized clinical trial. J Strength Cond Res 30(12): 3494–3502, 2016—The study evaluated the effects of concurrent training on resting heart rate variability (HRVrest) and cardiorespiratory fitness in people living with HIV/AIDS undergoing antiretroviral therapy (ART). Fifty-eight participants were randomized into 2 groups (control and training group); however, only 33 were analyzed. The variables studied were HRVrest indices, submaximal values of oxygen uptake (V[Combining Dot Above]O2sub) and heart rate (HR5min), peak speed (Vpeak), and peak oxygen uptake (V[Combining Dot Above]O2peak). The training group performed concurrent training (15–20 minutes of aerobic exercise plus 40 minutes of resistance exercise), 3 times per week, for 16 weeks. Posttraining V[Combining Dot Above]O2peak and Vpeak increased, and HR5min decreased. Resting heart rate variability indices did not present statistical differences posttraining; however, the magnitude-based inferences demonstrated a “possibly positive effect” for high frequency (HF) and low frequency (LF) plus high frequency (LF + HF) and a “likely positive effect” for R-Rmean posttraining. In conclusion, concurrent training was effective at improving cardiorespiratory fitness and endurance performance. Moreover, it led to probably a positive effect on HF and a likely positive effect on R-Rmean in people living with HIV/AIDS undergoing ART.

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.