Lúcio Flávio Soares-Caldeira

Noninvasive method to estimate anaerobic threshold in individuals with type 2 diabetes

BackgroundWhile several studies have identified the anaerobic threshold (AT) through the responses of blood lactate, ventilation and blood glucose others have suggested the response of the heart rate variability (HRV) as a method to identify the AT in young healthy individuals. However, the validity of HRV in estimating the lactate threshold (LT) and ventilatory threshold (VT) for individuals with type 2 diabetes (T2D) has not been investigated yet.AimTo analyze the possibility of identifying the heart rate variability threshold (HRVT) by considering the responses of parasympathetic indicators during incremental exercise test in type 2 diabetics subjects (T2D) and non diabetics individuals (ND).MethodsNine T2D (55.6 ± 5.7 years, 83.4 ± 26.6 kg, 30.9 ± 5.2 kg.m2(-1)) and ten ND (50.8 ± 5.1 years, 76.2 ± 14.3 kg, 26.5 ± 3.8 kg.m2(-1)) underwent to an incremental exercise test (IT) on a cycle ergometer. Heart rate (HR), rate of perceived exertion (RPE), blood lactate and expired gas concentrations were measured at the end of each stage. HRVT was identified through the responses of root mean square successive difference between adjacent R-R intervals (RMSSD) and standard deviation of instantaneous beat-to-beat R-R interval variability (SD1) by considering the last 60 s of each incremental stage, and were known as HRVT by RMSSD and SD1 (HRVT-RMSSD and HRVT-SD1), respectively.ResultsNo differences were observed within groups for the exercise intensities corresponding to LT, VT, HRVT-RMSSD and HHVT-SD1. Furthermore, a strong relationship were verified among the studied parameters both for T2D (r = 0.68 to 0.87) and ND (r = 0.91 to 0.98) and the Bland & Altman technique confirmed the agreement among them.ConclusionThe HRVT identification by the proposed autonomic indicators (SD1 and RMSSD) were demonstrated to be valid to estimate the LT and VT for both T2D and ND.

Cardiac autonomic responses to repeated shuttle sprints.

Team sport match play requires athletes to perform a number of repeated shuttle sprints. However, the acute effects of these repeated sprint sequences on lactic acidosis and resulting autonomic state perturbation are not known. The aim of this study was to observe and compare the blood lactate and post-exercise cardiac autonomic responses of a repeated shuttle-sprint ability test with the 30-15 Intermittent Fitness Test (30-15 (IFT)); the latter test representing a standard for exhaustive supramaximal effort. Thirteen adult team sport players performed the repeated shuttle-sprint ability test and the 30-15 (IFT) on separate days in a counter-balanced order. The repeated shuttle-sprint ability test consisted of six repetitions of maximal 2x15 m shuttle sprints ( approximately 5 s) departing every 20 s, while the 30-15 (IFT) involved progressive 30 s shuttle runs interspersed with 15 s of passive recovery until exhaustion. Blood lactate was measured before and after the tests, while autonomic responses were assessed using immediate heart rate recovery and heart rate variability indices. Peak blood lactate (10.6+/-2.1 vs. 10.2+/-2.8 mM) and heart beats recovered in one minute after exercise cessation (36.4+/-7.8 vs. 39.3+/-7.9 bpm) were similar after both the repeated shuttle-sprint ability test and the 30-15 (IFT). With the exception of the vagal-related time-varying root mean square of successive R-R interval differences at each 30 s, which recovered earlier after the repeated shuttle-sprint ability test compared with 30-15 (IFT), all heart rate variability indices decreased similarly after both tests in comparison to baseline values. In conclusion, the repeated shuttle-sprint ability test was shown to induce comparable levels of lactic acidosis and post-exercise autonomic state as the 30-15 (IFT). These levels of metabolic and autonomic states are likely to occur during team sport match play.

Effects of additional repeated sprint training during preseason on performance, heart rate variability, and stress symptoms in futsal players: a randomized controlled trial.

Abstract Soares-Caldeira, LF, de Souza, EA, de Freitas, VH, de Moraes, SMF, Leicht, AS, and Nakamura, FY. Effects of additional repeated sprint training during preseason on performance, heart rate variability, and stress symptoms in futsal players: A randomized controlled trial. J Strength Cond Res 28(10): 2815–2826, 2014—The aim of this study was to investigate whether supplementing regular preseason futsal training with weekly sessions of repeated sprints (RS) training would have positive effects on repeated sprint ability (RSA) and field test performance. Thirteen players from a professional futsal team (22.6 ± 6.7 years, 72.8 ± 8.7 kg, 173.2 ± 6.2 cm) were divided randomly into 2 groups (AddT: n = 6 and normal training group: n = 7). Both groups performed a RSA test, Yo-Yo intermittent recovery test level 1 (YoYo IR1), squat (SJ) and countermovement jumps (CMJ), body composition, and heart rate variability (HRV) measures at rest before and after 4 weeks of preseason training. Athletes weekly stress symptoms were recorded by psychometric responses using the Daily Analysis of Life Demands for Athletes questionnaire and subjective ratings of well-being scale, respectively. The daily training load (arbitrary units) was assessed using the session of rating perceived exertion method. After the preseason training, there were no significant changes for body composition, SJ, CMJ, and RSAbest. The YoYo IR1, RSAmean, RSAworst, and RSAdecreament were significantly improved for both groups (p ⩽ 0.05). The HRV parameters improved significantly within both groups (p ⩽ 0.05) except for high frequency (HF, absolute and normalized units, [n.u.]), low frequency (LF) (n.u.), and the LF/HF ratio. A moderate effect size for the AddT group was observed for resting heart rate and several HRV measures. Training load and psychometric responses were similar between both groups. Additional RS training resulted in slightly greater positive changes for vagal-related HRV with similar improvements in performance and training stress during the preseason training in futsal players.

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.

The Effects of 17 Weeks of Ballet Training on the Autonomic Modulation, Hormonal and General Biochemical Profile of Female Adolescents

Abstract This study aimed to examine the alterations in physiological and biochemical markers, after 17 weeks of ballet training in high level ballet dancers. Twenty four female ballet dancers from 12 to 15 years old took part in the study. The study followed 17 weeks of ballet training and analyzed changes in body composition, the autonomic nervous system and biochemical variables before and after (post) training. The internal training load was obtained using the session rating of perceived exertion (session-RPE) method, calculated as the mean weekly session-RPE, monotony and strain. After 17 weeks of training there were significant increases in body mass, height, lean body mass, total protein, urea, hemoglobin concentration, testosterone and thyroxine. During this period, decreases in relative body fat, uric acid, red blood cells, C-reactive protein, and ferritin were also found. After the training period, the autonomic modulation demonstrated significant positive alterations, such as increases in parasympathetic related indices. Based on the results obtained we concluded that ballet training led to improvements in body composition and autonomic modulation. In general hematological and biochemical variables demonstrated that the training did not have adverse effects on the health state of the adolescents.

Predição do desempenho aeróbio na canoagem a partir da aplicação de diferentes modelos matemáticos de velocidade crítica

O modelo de velocidade critica com dois parâmetros vem sendo utilizado para a determinacao do desempenho aerobio e anaerobio. No entanto, o modelo com tres parâmetros preve um parâmetro adicional correspondente a velocidade instantânea maxima (Vmax) ao modelo original, tendo impacto sobre a estimativa dos outros dois parâmetros. Sendo assim, o objetivo deste trabalho foi verificar e comparar a relacao da velocidade critica (VCrit), fornecida pelos modelos com dois (VCrit-2parâmetros) e tres (VCrit-3parâmetros) parâmetros, com a velocidade media mantida em esforco maximo de 6.000m (V6000m) na canoagem. Nove canoistas (17,4 ± 2,4 anos) competitivos do sexo masculino realizaram, em dias diferentes, testes maximos de 200, 500, 1.000, 1.800 e 6.000m. A VCrit foi calculada para todos os sujeitos, a partir das distâncias de 200 a 1.800m, utilizando-se as equacoes hiperbolicas com dois e tres parâmetros. As duracoes dos percursos ficaram no intervalo entre 46,1 ± 2,5s e 513,9 ± 25,6s. Para comparacao entre as velocidades (VCrit-2parâmetros, VCrit-3parâmetros e V6000m) foi utilizada ANOVA one way para medidas repetidas, seguida pelo teste post hoc de Newman-Keuls. A associacao entre as variaveis foi feita a partir de correlacao de Pearson. Para analise de concordância foi aplicada a plotagem de Bland-Altman entre os valores de VCrit-2parâmetros, VCrit-3parâmetros e V6000m . Em media, o tiro de 6.000m teve duracao de 29,9 ± 1,0 min. Houve diferenca significante da VCrit-3parâmetros (2,93 ± 0,36m/s) em relacao a VCrit-2parâmetros (3,31 ± 0,22m.s-1) e V6000m (3,35 ± 0,11m.s-1). VCrit-2parâmetros e V6000m nao diferiram entre si. A correlacao entre VCrit-2parâmetros e V6000m foi de 0,72 (p = 0,03), enquanto que a entre VCrit-3parâmetros e V6000m nao foi significante. Os resultados deste estudo sugerem que o modelo de velocidade critica de dois parâmetros fornece valor de VCrit mais adequado para a avaliacao aerobia de canoistas. A VCrit-3parâmetros subestima a velocidade que pode ser mantida por aproximadamente 30 min, com baixa capacidade preditiva de desempenho aerobio. Assim, foram obtidas evidencias de validade do modelo original de velocidade critica de dois parâmetros proposto por Monod e Scherrer.