Superior bioavailability of the calcium salt form of ß-hydroxy-ß-methylbutyrate compared with the free acid form.

We investigated the bioavailability of the calcium salt (HMB-Ca) and the free acid (HMB-FA) forms of ß-hydroxy-ß-methylbutyrate (HMB). Sixteen young individuals received the following treatments on three different occasions in a counterbalanced crossover fashion: (1) HMB-FA in clear capsules; (2) HMB-Ca in gelatine capsules; (3) HMB-Ca dissolved in water. All treatments provided 1 g of HMB. Blood samples were taken before and on multiple time points following ingestion. The following parameters were calculated: peak plasma (Cmax), time to peak (Tmax), slope of HMB appearance in blood, area under the curve (AUC), half-life time (t1/2) and relative bioavailability (HMB-Ca in water set as reference). All treatments led to rapid and large increases in plasma HMB. HMB-Ca in capsules and in water showed similar plasma HMB values across time (p = 0.438). HMB-FA resulted in lower concentrations vs. the other treatments (both p < 0.001). AUC (HMB-Ca in capsules: 50,078 ± 10,507; HMB-Ca in water: 47,871 ± 10,783; HMB-FA: 29,130 ± 12,946 µmol L-1 × 720 min), Cmax (HMB-Ca in capsules: 229.2 ± 65.9; HMB-Ca in water: 249.7 ± 49.7; HMB-FA: 139.1 ± 67.2 µmol L-1) and relative bioavailability (HMB-Ca in capsules: 104.8 ± 14.9%; HMB-FA: 61.5 ± 17.0%) were lower in HMB-FA vs. HMB-Ca (all p < 0.001). HMB-Ca in water resulted in the fastest Tmax (43 ± 22 min) compared to HMB-Ca in capsules (79 ± 40 min) and HMB-FA (78 ± 21 min) (all p < 0.05), while t1/2 was similar between treatments. To conclude, HMB-Ca exhibited superior bioavailability compared to HMB-FA, with HMB-Ca in water showing faster absorption. Elimination kinetics were similar across all forms, suggesting that the pharmaceutical form of HMB affects the absorption rates, but not its distribution or elimination.

Kinematic Comparison of the Roundhouse Kick Between Taekwondo, Karate, and Muaythai.

ABSTRACT: Diniz, R, Del Vecchio, FB, Schaun, GZ, Oliveira, HB, Portella, EG, da Silva, ES, Formalioni, A, Campelo, PCC, Peyré-Tartaruga, LA, and Pinto, SS. Kinematic comparison of the roundhouse kick between taekwondo, karate, and muaythai. J Strength Cond Res 35(1): 198-204, 2021-The roundhouse kick (RHK) is frequently executed in taekwondo, karate, and muaythai because of its high technical effectiveness during combat. The purpose of this study was to compare kinematic characteristics during RHK performance between taekwondo, karate, and muaythai athletes. Forty-seven male athletes (25.5 ± 4.7 years, 1.75 ± 0.1 m, and 75.8 ± 11.5 kg) volunteered to participate (taekwondo: 17; karate: 15; and muaythai: 15). Self-selected distance from target, mean and peak fifth metatarsus linear velocity (LV5mean; LV5peak), mean and peak hip (HAVmean; HAVpeak) and knee (KAVmean; KAVpeak) angular velocities, as well as target linear acceleration (TLA) were analyzed with a 3D video motion analysis system. Comparisons between modalities were performed with 1-way analysis of variances and Bonferroni's post hoc test (α = 0.05). Self-selected distance was lower in muaythai compared with taekwondo and karate (p < 0.001). Also, karate had greater LV5mean compared with muaythai (p = 0.001), and muaythai showed higher HAVmean than karate (p = 0.011). In addition, HAVpeak was greater in muaythai than in taekwondo and karate (p < 0.001). No differences were found for KAVmean, KAVpeak, and TLA. Although it is similarly described between modalities, RHK showed distinct kinematic characteristics between taekwondo, karate, and muaythai. Based on these results, coaches and athletes can improve their RHK technique according to the specificities of each combat sport. Specifically, it is suggested that combat strategies should aim to increase the distance from the opponent during combat for muaythai athletes, whereas taekwondo and karate athletes should focus on decreasing it.

AUTONOMIC, CARDIOVASCULAR & PHYSIOLOGICAL RESPONSES IN STRENGTH TRAINING PROTOCOLS / Respostas autonômicas, cardiovasculares e fisiológicas em protocolos de treinamento de força / Respuestas autonómicas, cardiovasculares y fisiológicas en protocolos de entrenamiento de fuerza

ABSTRACT Introduction Strength training is a recurrent practice among several publics and the topic of several studies, yet there is a shortage of previous studies that analyzed these parameters in the same subjects in training sessions involving volume, interval and different repetitions maximum ranges. Objective The study was aimed at measuring and comparing the acute effect of different ST (strength training) protocols on HR (heart rate), HRV (heart rate variability), [LAC] (lactate concentration), [CK] (creatine kinase) and SPE (subjective perceived exertion). Methods Eleven individuals with previous experience were recruited and in three sessions they performed three different training models, namely: high load (4 sets at 90% of 1RM, 180s rest between sets), medium load (3 sets at 75% of 1 RM, 90s rest between sets), and low load (2 sets at 50% of 1 RM, 45s rest between sets) in free squat, bench press, deadlift and bent-over row exercises. Results There was no difference in CK between low load (resistance) and medium load (hypertrophy) (p = 0.60), between resistance and high load (strength) (p = 0.84), and between hypertrophy and strength (p = 0.91), while there was higher lactate accumulation in training with medium and low loads in comparison to training with high loads (p <0.001). Conclusion It can be noted that workouts with high loads, few repetitions and longer intervals (maximum strength) generate lower blood lactate concentrations and SPE values when compared to training with lower loads and shorter intervals (resistance training and hypertrophy). Additionally, when evaluating autonomic and cardiovascular variables, it would appear that manipulating the percentage of 1RM and the interval time does not generate significant changes in HRV, blood pressure (BP) and HR when the repetitions are executed until failure. Level of evidence II; Prospective comparative study.

RESUMO Introdução O treinamento de força é prática recorrente entre diversos públicos e alvo de diversos estudos, contudo há escassez de estudos prévios que analisaram esses parâmetros nos mesmos indivíduos em sessões de treino envolvendo volume, intervalo e faixas distintas de repetições máximas. Objetivo Mensurar e comparar o efeito agudo de diferentes protocolos de TF (treino de força) sobre a FC (frequência cardíaca), VFC (variabilidade da frequência cardíaca), [LAC] (concentração de lactato), [CK] (creatina quinase) e PSE (percepção subjetiva de esforço). Métodos Foram selecionados 11 indivíduos com experiência prévia e, em três sessões, os mesmos realizaram três diferentes modelos de treino, isto é: carga alta (4 séries a 90% de 1RM, 180s de descanso entre séries), carga média (3 séries a 75% de 1 RM, 90s de descanso entre séries) e carga baixa (2 séries a 50% de 1 RM, 45s de descanso entre séries) em exercícios de agachamento livre, supino reto, levantamento terra e remada curva. Resultados Não houve diferença da CK entre a carga baixa (resistência) e a carga média (hipertrofia) (p=0,60), entre resistência e carga alta (força) (p=0,84) e entre hipertrofia e força (p=0,91) e houve maior acúmulo de lactato nos treinos com carga média e baixa em relação ao treino com cargas altas (p<0,001). Conclusão Observa-se que os treinos com cargas altas, poucas repetições e intervalos mais longos (força máxima) geram concentrações de lactato sanguíneo e PSE menores quando comparados aos treinos que utilizam cargas mais baixas e intervalos mais curtos (treinos de resistência e hipertrofia). Adicionalmente, quando avaliadas as variáveis autonômicas e cardiovasculares, parece que manipular o percentual de 1RM e o tempo de intervalo não é capaz de gerar alterações significativas na VFC, pressão arterial (PA) e FC quando as repetições são executadas até a falha. Nível de evidência II; Estudo prospectivo comparativo.

RESUMEN Introducción El entrenamiento de fuerza es práctica recurrente entre diversos públicos y objetivo de diversos estudios. Sin embargo, hay escasez de estudios previos que analizaron esos parámetros en los mismos individuos en sesiones de entrenamiento abarcando volumen, intervalo y franjas distintas de repeticiones máximas. Objetivo Medir y comparar el efecto agudo de diferentes protocolos de EF (entrenamiento de fuerza) sobre la FC (frecuencia cardíaca), VFC (variabilidad de la frecuencia cardíaca), [LAC] (concentración de lactato), [CK] (creatina quinasa) y PSE (percepción subjetiva de esfuerzo). Métodos Fueron seleccionados 11 individuos con experiencia previa y, en tres sesiones, los mismos realizaron tres modelos de entrenamiento, a saber: carga alta (4 series a 90% de 1RM, 180s de descanso entre series), carga mediana (3 series a 75% 1RM, 90s de descanso entre series), y carga baja (2 series a 50% de 1RM, 45s de descanso entre series) en los ejercicios de agachamiento libre, supino recto, levantamiento tierra y remada curva. Resultados No hubo diferencias de la CK entre la carga baja (resistencia) y la carga mediana (hipertrofia) (p = 0,60) entre resistencia y carga alta (fuerza) (p = 0,84) y entre hipertrofia y fuerza (p = 0,91) y hubo mayor acumulación de lactato en los entrenamientos con carga mediana y baja con relación al entrenamiento con cargas altas (p <0,001). Conclusión Se observa que los entrenamientos con cargas altas, pocas repeticiones e intervalos más largos (fuerza máxima) generan concentraciones de lactato sanguíneo y PSE menores cuando comparados a los entrenamientos que utilizan cargas más bajas e intervalos más cortos (entrenamientos de resistencia e hipertrofia). Además, cuando evaluadas las variables autonómicas y cardiovasculares, parece que manipular el porcentaje de 1RM y el tiempo de intervalo no es capaz de generar alteraciones significativas en la VFC, presión arterial (PA) y FC cuando las repeticiones son ejecutadas hasta la falla. Nivel de evidencia II; Estudio prospectivo comparativo.

Anthropometric characteristics and physical performance of taekwondo athletes / Características antropométricas e desempenho físico de lutadores de taekwondo

Abstract The purpose of this investigation was to measure anthropometric and physical performance variables of TKD athletes from the city of Pelotas - RS. Forty-five athletes aged 16.4 ± 5.2 years and time of practice of 3.25 ± 3.6 years were evaluated. Athletes performed anthropometric evaluation and physical, general and specific performance tests. In the sum of seven skin folds, men presented lower values ??(106.1 ± 49.5 mm versus 143.4 ± 43.2 mm, p <0.002). Male seniors presented better performance in the vertical jump compared to beginners (42.3 ± 8.5cm versus 24.8 ± 10.1cm, p <0.03) and to women (22.1 ± 4.3cm, p <0.03). Graduated individuals perform higher number of arm pushups than beginners and women and more repetitions in the abdominal test. Male junior and senior athletes had higher isometric handgrip strength than females (48.3 ± 3.9 kgf and 38.1 ± 12.6 kgf versus 29 ± 5.6 kgf, p <0.001). Men covered longer distance in the yo-yo test than women (606.6 ± 233.8m versus 200 ± 113.1m, p <0.001). In the Wingate test, men produced greater peak and average relative power. No differences in flexibility were observed. In the single kick test, seniors kicked faster than less experienced athletes (200.6 ± 12.3m / s versus 258 ± 5.6m / s, p <0.001) and performed greater number of kicks in the 21s, 6 ± 2.1 reps versus 15.5 ± 0.7 reps, p <0.001). It was concluded that there are differences between male and female TKD athletes regarding anthropometric and motor characteristics, and that more experienced athletes exhibit greater general and specific physical fitness.

Resumo O objetivo desta investigação foi mensurar variáveis antropométricas e de desempenho físico de atletas de TKD da cidade de Pelotas - RS. Foram avaliados 45 atletas com idades 16,4±5,2 anos e tempo de prática de 3,25± 3,6 anos. Os atletas realizaram avaliação antropométrica, testes de desempenho físico, gerais e específicos. No somatório de sete dobras cutâneas, homens apresentam menores valores (106,1±49,5mm versus 143,4±43,2mm; p<0,002). Homens mais graduados apresentaram melhor desempenho no salto vertical que homens iniciantes (42,3±8,5cm versus 24,8±10,1cm; p<0,03) e que mulheres (22,1±4,3cm; p<0,03). Indivíduos graduados realizam maior número de flexões de cotovelo que iniciantes e mulheres e mais repetições no teste de abdominais. Atletas da categoria sênior e júnior masculino exibiram mais força isométrica de preensão manual que as mulheres (48,3±3,9kgf e 38,1±12,6kgf versus 29±5,6kgf; p<0,001). Homens percorreram maior distância no yo-yo test que mulheres (606,6±233,8m versus 200±113,1m; p<0,001). No teste de Wingate, homens produziram maior potência relativa máxima e média. Não foram observadas diferenças na flexibilidade. No teste de chute único, indivíduos mais graduados chutaram mais rápido do que os menos graduados (200,6±12,3m/s versus 258±5,6m/s; p<0,001) e executam maior número de chutes em 10s (21,6±2,1reps versus 15,5±0,7reps; p<0,001). Conclui-se que há diferenças entre homens e mulheres praticantes de TKD quanto a características antropométricas e motoras, e que atletas mais avançados exibem maior aptidão física geral e específica.

The validity of Keiser-M3 stationary bicycle with standard ergometer for physiological measurements associated with maximum effort

Abstract Aim: This study aims to investigate the concordance between two cycle ergometers for variables measured in the test of maximum incremental effort. Methods: This correlation study enrolled 15 inactive women (19,2 ± 4,0 years old). At random, the participants performed two maximal effort incremental tests (MEIT), using cycle ergometers (Keiser-M3 and Ergo-167) on different days with a minimum interval of 72 hours. The test had stages of two minutes, and two-step increments were carried out at the end of each stage. Lactate concentration ([LAC]), and rated perceived exertion (RPE) were collected, in addition to monitoring oxygen uptake (VO2) and heart rate (HR). The Paired t-test was carried out to compare physiologic variables, Lin's test was used for correlation, and Bland Altman was used to measuring concordances among variables. Results: The correlations between physiologic parameters were considered strong for HR on the anaerobic threshold (Keiser M3 = 146 ± 14 bpm; Ergo-167 = 149 ± 9 bpm; r = 0.762), greater blood lactate value (Keiser M3 = 9,97 ± 2,51 mmol/L; Ergo-167 = 9.71 ± 2.56 mmol/L; r = 0.820), VO2max (Keiser M3 = 38,37 ± 6,97 mL/kg/min; Ergo-167 = 36.06 ± 8.4 mL/kg/min; r = 0,806) and HRmax (Keiser M3 = 186 ± 53 bpm; Ergo-167 = 188 ± 11 bpm; r = 0.716). Conclusion: The results show the feasibility of using the cycle ergometer Keiser, model M3, to perform the maximal effort incremental test, whereas there was high concordance in the physiologic responses in both ergometers for inactive women.

Acute responses of high-intensity circuit training in women: Low physical fitness levels show higher muscle damage / Respostas agudas de um circuito de treino de alta intensidade em mulheres: Níveis baixos de aptidão física apresentam maior dano muscular

High-intensity intermittent exercise (HIIE) elicits large improvements in health and cardiorespiratory fitness (CRF). HIIE can be applied with calisthenics exercises to improve strength and endurance. The acute effects of high-intensity circuit training (HICT) considering different CRF on myological variables are unknown. The aim was measure acute effects of HICT in young women considering different levels of CRF. Twelve women were allocated in two groups, who achieve 41mLO2•kg-1•min-1 or more= High Physical Fitness (HPF, n=5) and who achieve less than 41mLO2•kg-1•min-1= Low Physical Fitness (LPF,n=7). Protocol: 2x4 sets of 20 seconds at maximum intensity (all-out fashion) interspersed with 10 seconds of passive rest (jumping jacks, squat and thrust using 2kg dumbbells, mountain climber, and burpees). Blood samples were collected before, immediately after, 15minutes, 30minutes, one hour and 24 hours after. Heart rate, serum myoglobin, lactate, and creatine kinase (CK) concentration were analyzed. The HR achieved 94.1±3.7% of HRmax for LPF and 104.5±20.3% for HPF, p=0.03. The mean of delta lactate was similar between groups. The highest myoglobin has reached at 1h after the exercise protocol, with 50.0±30.2 ng/mL for LPF and 36.9±9.25 ng/mL for HPF. The delta of total CK before and after the exercise protocol shows that the serum CK level in LPF was significantly higher than HPF group (p=0.042). HICT composed by calisthenic protocol produced elevated and similar effects on HRmax, serum lactate and myoglobin in the woman with HPF and LPF. However, LPF group presented higher muscle damage inferred by serum CK concentrations.

O exercício intermitente de alta intensidade(HIIE) melhora a saúde e a aptidão cardiorrespiratória(CRF). HIIE pode ser aplicado com exercícios calistênicos para melhorar a força e resistência. Os efeitos agudos do treinamento de alta intensidade(HICT) considerando diferentes CRF em variáveis miológicas são desconhecidos. O objetivo foi medir os efeitos agudos do HICT em mulheres jovens, considerando diferentes níveis de CRF. Elas foram alocadas pelo nível de VO2máx. em dois grupos, as que atingiram 41mLO2•kg-1•min-1 ou mais= alta aptidão física(HPF,n=5) e menos de 41mLO2•kg-1•min-1= baixo aptidão física(LPF,n=7). Protocolo: 2x4 séries de 20s com intensidade máxima (all-out) intercalados com 10s de repouso passivo (jumping jacks, squat and thrust usando halteres 2kg, mountain climber e burpees). Sangue foi coletado antes, zero, 15, 30min, 1h e 24hs depois. Foram analisadas, freqüência cardíaca, mioglobina sérica, lactato e creatina quinase (CK). A FC alcançou 94,1±3,7% da FCmax para LPF e 104,5±20,3% para HPF, p=0,03. A média do delta lactato foi semelhante entre os grupos. O pico de mioglobina foi 1h após o protocolo de exercício, com 50.0±30.2ng/mL para LPF e 36.9±9.25ng/mL para HPF. O delta de CK total antes e depois do protocolo de exercício mostra que o nível sérico de CK no LPF foi significativamente maior do que o grupo HPF(p=0,042). O HICT com exercícios calistênicos produziu efeitos elevados e semelhantes sobre FCmax, lactato sérico e mioglobina nas mulheres com alta e baixa aptidão física. No entanto, o grupo LPF apresentou maior dano muscular inferido pelas concentrações séricas de CK.

Comparação das respostas fisiológicas durante a prática de exergame e atividades convencionais: uma revisão sistemática com metanálise / Comparison of physiological responses during practices of exergames and conventional activities: a systematic review and meta-analysis

O objetivo do presente trabalho foi realizar revisão sistemática com metanálise dos estudos sobre efeitos fisiológicos da prática de exergames, a fim de compará-las quando realizadas de maneira convencional. As buscas foram realizadas nas bases eletrônicas: PubMed, Science Direct, Google Scholar e a revista Games For Health Journal, utilizando os seguintes descritores ou termos: "health video game" OR "active video game" AND "energy expenditure"; exergam* AND "physical activity"; exergam* AND comparison; exergam* compared to real; exergam* AND "real game"; exergam* AND "real sports". Para serem incluídos, além de serem originais, os artigos também deveriam comparar a realização das atividades convencionais igualmente efetivadas com exergame (EXG). Foram encontrados 2.928 estudos que abordaram a temática. Após avaliação por títulos, 13 artigos foram excluídos por serem duplicatas. No total foram lidos 20 resumos, no entanto, selecionamos apenas sete para entrar na revisão. Além disso, três estudos localizados nas listas de referências foram incluídos. Os estudos que passaram pelos filtros de análise acabaram submetidos à escala PEDro, para mensuração de qualidade metodológica. A metanálise apontou não haver diferença significativa, entre atividades com EXG e atividades convencionais, para frequência cardíaca (p = 0,248), percepção subjetiva de esforço (p = 0,295), gasto energético (p = 0,664) e consumo de oxigênio (p = 0,455). Desta maneira, conclui-se que não há diferença para as variáveis apresentadas em ambas as atividades propostas.

The aim of this study was to perform a systematic review and metanalysis on the physiological effects of exergames practice compared to the same activities performed in a conventional manner. Therefore, a search was made in the databases PubMed, Science Direct, Google Scholar and Games For Health magazine using the following descriptors or terms "health video game" oR "active video game" AND "energy expenditure"; exergam * AND "physical activity"; exergam * AND comparison; exergam * Compared to real; exergam * AND "real game"; exergam * AND "real sports". To be included in the review, studies should be original articles and rely on activities performed with active videogames, namely exergames (EXG), which should be compared with the same conventional activities. An amount of 2928 studies were found. After title evaluation, 13 studies were excluded for duplication, lasting 20 titles. After abstract's evaluation, 7 titles were selected for entering this study. Besides, 3 other studies were found in reference lists and were included.Studies passed by search filters were submitted to PEDro scale for methodological quality evaluation. Metanalysis showed no significant differences for heart rate (p=0.248), rating of perceived exertion (p=0.295), energy expenditure (p=0.664) and oxygen uptake (p=0.455) between EXG and conventional activities. In conclusion, there are no differences between activities with EXG and the same activities realized in a conventional manner on heart rate, rate of perceived exertion, energy expenditure and oxygen consumption.