ABSTRACT
Backgroud: Heart rate variability (HRV) measurement is an important tool that may help indicate possible physiological changes, and HRV monitorization could be a great strategy for clinical analysis (autonomic control) and performance (internal load).Objective: The aim of the present study was to evaluate autonomic responses and internal load through HRV during a higintensity functional training (HIFT) session.Material and method: Thirty-three individuals (22 men and 11 women) participated in the study (Age: Mean = 34.9 ± 7.2years; Weight: Mean = 72.3 ± 13.7 kg; Height: Mean = 1.72 ± 0.1 m; BMI: Mean = 24.4 ± 3.0 kg/m²). All participants engaged ina 60-to-90-minute HIFT session. HRV analysis was performed during the specific warm-up period (targeted warm-up or skilltraining that followed the general mobility and light cardiovascular warm-up), during exercise (approximately 50 minutes),and in the recovery phase (10 minutes post-training). A Polar H10 heart rate monitor chest strap (Kempele, Finland®) wasused to collect HRV and was connected to the Elite HRV mobile application. The data were further transferred to Kubios HRVStandart software, version 3.3.1, in order to process the acquired data.Results: For isolated analyzes (pre- and post-), differences were found for SDNN (P<0.001), RMSSD (P<0.001) and HF(P=0.041), yet not for LF / HF (P=0.483). In the analysis of HRV kinetics, significant results were found between momentsfor RR, SDNN, RMSSD, LF and HF (P<0.05). In the analysis of the internal load, the highest level of stress was identified in 40(P=0.010) and 50 minutes of exercise (P=0.001), as well as in recovery (P<0.001), this assessment being carried out throughHRV through the LnRMSSD index. A negative correlation was observed between maximum heart rate (HRmax) and LnRMSSDat 40 (r=-0.51) and 50 minutes of exercise (r=-0.58). In recovery, the correlation was positive, yet insignificant (r=0.032)...(AU)
Introducción: La medición de la variabilidad de la frecuencia cardiaca (HRV) es una herramienta importante que puedeayudar a indicar posibles cambios fisiológicos. La monitorización de la HRV podría ser una gran estrategia para el análisisclínico (control autonómico) y el rendimiento (carga interna).Objetivo: El objetivo del presente estudio fue evaluar las respuestas autonómicas y la carga interna a través de la VFC duranteuna sesión de entrenamiento funcional de alta intensidad (HIFT).Material y método: Treinta y tres individuos (22 hombres y 11 mujeres) participaron en el estudio (Edad: Media = 34,9 ±7,2 años; Peso: Media = 72,3 ± 13,7 kg; Altura: Media = 1,72 ± 0,1 m; IMC: Media = 24,4 ± 3,0 kg / m²). Todos los participantesparticiparon en una sesión HIFT de 60 a 90 minutos. El análisis de la VFC se realizó durante el periodo de calentamiento específico (calentamiento dirigido o entrenamiento de habilidades que seguía al calentamiento cardiovascular ligero y demovilidad general), durante el ejercicio (aproximadamente 50 minutos) y en la fase de recuperación (10 minutos despuésdel entrenamiento). Se utilizó una banda de pecho con pulsómetro Polar H10 (Kempele, Finlandia®) para recoger la VFC y seconectó a la aplicación móvil Elite HRV. Los datos se transfirieron posteriormente al software Kubios HRV Standart, versión3.3.1, para procesar los datos adquiridos.Resultados: En los análisis aislados (pre y post), se encontraron diferencias para SDNN (p <0,001), RMSSD (p <0,001) y HF(p = 0,041), pero no para LF / HF (p = 0,483). En el análisis de la cinética de la VFC, se encontraron resultados significativos entremomentos para RR, SDNN, RMSSD, LF y HF (p <0,05). En el análisis de la carga interna, el mayor nivel de estrés se identificóen 40 (p = 0,010) y 50 minutos de ejercicio (p = 0,001), así como en la recuperación (p <0,001), realizándose esta valoración...(AU)
Subject(s)
Humans , Male , Female , Adult , Athletes , Resistance Training , Heart Rate , Exercise , Physical Functional Performance , Sports Medicine , Psychology, Sports , SportsABSTRACT
The purpose of the present study was to verify the acute effect of sodium bicarbonate supplementation on symptoms of gastrointestinal discomfort, acid-base balance and intermittent isometric handgrip test performance in Jiu-Jitsu athletes. Ten male (22.2 ± 3.9 years; 174 ± 0.07 cm; 74.5 ± 8.9 kg) jiu-jitsu athletes participated in this counterbalanced double-blind crossover study. Two protocols, a) supplementation with 0.3 g.kg-1 of body weight of sodium bicarbonate, and b) supplementation with 0.045 g.kg-1 of body weight of placebo substance, were employed. Gastrointestinal tolerability was assessed by the questionnaire. Blood samples were collected at three time points (baseline, pre-ISO, and post-ISO) to determine the responses of potential hydrogenionic (pH), bicarbonate (HCO3- ), base excess (EB) and lactate concentrations. The maximum voluntary contraction test and the intermittent isometric contraction test were also performed. As a result, none of the athletes reported significant gastrointestinal discomfort (p > 0.05). HCO3- , pH, and EB at the pre-ISO and post-ISO moments were significantly higher for the sodium bicarbonate protocol. Lactate concentrations were significantly higher for both post-ISO protocols (p = 0.000). There was no significant difference in the performance of the maximum voluntary contraction test and the intermittent isometric contraction test (p > 0.05). Thus, we conclude that sodium bicarbonate supplementation does not generate adverse responses resulting in gastrointestinal discomfort, and does not benefit performance yet promotes a state of metabolic alkalosis.
ABSTRACT
Ischemic preconditioning (IPC) has been used to increase performance in sports. The aim of this study was to compare the acute effects of IPC with different warm-up methods on the number of repetitions and total volume in resistance exercise (RE). Sixteen healthy men recreationally trained in RE participated in this study. After the anthropometric evaluation and familiarization, a one-repetition maximum (1RM) test and retest were performed in the bench press (BP) and in the leg press 45° (LP) exercise. After these tests, participants were randomly assigned to one of the five protocols: a) IPC; b) SHAM; c) a specific warm-up (SW); d) aerobic exercise (AE), and e) active stretching (AS) prior to performing 3 sets at 80% 1RM until concentric failure. The number of repetitions was higher following IPC compared to the SW following three sets both for the BP and LP. Similarly, the number of repetitions for IPC was higher in comparison to SHAM following three sets for the LP. The number of repetitions was higher following IPC compared to AE following 1st and 2nd sets for the LP and following the 2nd set for the BP. Finally, the number of repetitions was higher following IPC compared to AS following 1st and 2nd sets for the LP. The total volume was higher following IPC compared to SHAM, SW, AE, and AS for both the BP and LP. The IPC protocol increased the number of maximum repetitions and the total volume when compared to the other tested methods, thus indicating a better utilization during the pre-work warm-up. These results indicate positive associative responses to IPC with performance maintenance, which is of importance for both athletes and coaches.
ABSTRACT
En este trabajo se estudió la relación entre las dimensiones antropométricas y la insatisfacción corporal en socios de gimnasios. Los participantes fueron 276 personas de Brasil socios de centros de fitness (168 varones y 108 mujeres) de una edad comprendida entre los 17 y 39 años (m = 23.93, sd = 5.17). después de la medición de la masa corporal (Mc), del índice de masa corporal (IMc) y de la porcentaje de grasa corporal (% Gc), los participantes indicaran las siluetas más semejantes a su apariencia corporal (silueta real sr) y a su apariencia corporal ideal (silueta ideal sI), lo que permitió el cálculo de la insatisfacción corporal como la discrepancia entre la sI y la sr. IMc y % Gc fueron agrupados por categorías de insatisfacción corporal y analizados por medio de ANoVA univariada y de medidas repetidas. Los resultados revelaron que sólo 1.2% de los hombres y 6.5% de las mujeres se consideraban satisfechos con su cuerpo. Las comparaciones de las sr por sexo indicaran que los hombres y mujeres consideran sus actuales sr significativamente menos corpulentas que las sI (p < .001), aunque el grado de insatisfacción fue semejante en ambos sexos. Además, los resultados demostraron que la relación entre la composición corporal y la insatisfacción corporal sólo se demuestra en personas que se sienten muy insatisfechas con su imagen y apariencia corporal (AU)
The purpose of this study was to identify the anthropometric dimensions related with body image dissatisfaction among fitness center users. Participants were 276 Brazilian members of fitness centers (168 males and 108 females) with ages between 17 and 39 years (mage = 23.93, sd = 5.17). After body mass (BM), body mass index (BMI) and body fat (% BF) were measured, participants indicated their current (cs) and ideal (Is) silhouettes, allowing the calculation of body dissatisfaction as the difference between Is and cs. BMI and % BF were grouped by body dissatisfaction category and analyzed using one-way and repeated measures ANoVA. results revealed that only 1.2 % of men and 6.5 % of women considered themselves satisfied with their body. comparisons of global ratings of their cs and Is revealed that male and female individuals reported that their current bodies were significantly less muscular than their ideal bodies (p < .001), although the degree of dissatisfaction revealed no significant difference between sexes. Moreover, results demonstrated that the relationship between body composition and body dissatisfaction only occurs in individuals that feel very dissatisfied with their body image and appearance (AU)
