Effects of Drop-Set and Pyramidal Resistance Training Systems on Microvascular Oxygenation: A Near-Infrared Spectroscopy Approach

International Journal of Exercise Science 13(2): 1549-1562, 2020. Metabolic stress is a primary mechanism of muscle hypertrophy and is associated with microvascular oxygenation and muscle activation. Considering that drop-set (DS) and crescent pyramid (CP) resistance training systems are recommended to modulate these mechanisms related to muscle hypertrophy, we aimed to investigate if these resistance training systems produce a different microvascular oxygenation status and muscle activation from those observed in traditional resistance training (TRAD). Twelve volunteers had their legs randomized in an intra-subject cross-over design in TRAD (3 sets of 10 repetitions at 75% 1-RM), DS (3 sets of ~50-75% 1-RM) and CP (3 sets of 6-10 repetitions at 75-85% 1-RM). Vastus medialis microvascular oxygenation and muscle activation were respectively assessed by non- invasive near-infrared spectroscopy and surface electromyography techniques during the resistance training sessions in the leg-extension exercise. Total hemoglobin area under the curve (AUC) (TRAD: -1653.5 ± 2866.5; DS: -3069.2 ± 3429.4; CP: -1196.6 ± 2675.3) and tissue oxygen saturation (TRAD: 19283.1 ± 6698.0; DS: 23995.5 ± 15604.9; CP: 16109.1 ± 8553.1) increased without differences between protocols (p\u3e0.05). Greater decreases in oxygenated hemoglobin AUC and hemoglobin differentiated AUC were respectively found for DS (-4036.8 ± 2698.1; -5004.4 ± 2722.9) compared with TRAD (-1951.8 ± 1720.0; -2250.3 ± 1305.7) and CP (-1814.4 ± 2634.3; 2432.2 ± 2891.4) (p\u3c0.03). Higher increases of hemoglobin deoxygenated AUC were found for DS (1426.7 ± 1320.7) compared with TRAD (316.0 ± 1164.9) only (p=0.04). No differences were demonstrated in electromyographic amplitudes between TRAD (69.0 ± 34.4), DS (61.3 ± 26.7) and CP (60.9 ± 38.8) (p\u3e0.05). Despite DS produced lower microvascular oxygenation levels compared with TRAD and CP, all protocols produced similar muscle activation levels

Crescent pyramid and drop-set systems do not promote greater strength gains, muscle hypertrophy, and changes on muscle architecture compared with traditional resistance training in welltrained men

Purpose The aim of this study was to compare the effects of crescent pyramid (CP) and Drop-set (DS) systems with traditional resistance training (TRAD) with equalized total training volume (TTV) on maximum dynamic strength (1-RM), muscle cross-sectional area (CSA), pennation angle (PA) and fascicle length (FL). Methods Thirty-two volunteers had their legs randomized in a within-subject design in TRAD (3-5 sets of 6-12 repetitions at 75% 1-RM), CP (3-5 sets of 6-15 repetitions at 65-85% 1-RM) and DS (3-5 sets of ~50-75% 1-RM to muscle failure) protocols. Each leg was trained for 12 weeks. Participants had one leg fixed in the TRAD while the contralateral leg performed either CP or DS to allow for TTV equalization. Results The CSA increased significantly and similarly for all protocols (TRAD: 7.6%; CP: 7.5%; DS: 7.8%). All protocols showed significant and similar increases in leg press 45º (TRAD = 25.9%; CP = 25.9%; DS = 24.9%) and leg extension 1-RM loads (TRAD = 16.6%; CP = 16.4%; DS = 17.1%). All protocols increased PA (TRAD = 10.6%; CP = 11.0%; DS = 10.3%) and FL (TRAD = 8.9%; CP = 8.9%; DS = 9.1%) similarly. Conclusion CP and DS systems do not promote greater gains in strength muscle hypertrophy and changes in muscle architecture compared to traditional resistance training.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Objetivo: Comparar os efeitos dos sistemas pirâmide crescente (PC) e Drop-set (DS) com o treinamento de força tradicional (TRAD) na força máxima dinâmica (1-RM), área de secção transversa muscular (AST), ângulo de penação (AP) e comprimento do fascículo (CF). Métodos: Trinta e dois voluntários tiveram as pernas aleatorizadas em um design intra-sujeito nas protocolos TRAD (3-5 séries de 6-12 repetições à 75% 1-RM), PC (3-5 séries de 6-15 repetições a 65-85% 1-RM) e DS (3-5 séries à ~50-75% 1-RM até a falha muscular). Cada perna foi treinada por 12 semanas. Os participantes tiveram uma perna fixada no protocolo TRAD, enquanto a perna contralateral realizou a protocolo PC ou DS. Resultados: A AST aumentou significantemente e similarmente para todos os protocolos (TRAD: 7,6%; CP: 7,5%; DS: 7,8%). Todos os protocolos demonstraram aumentos significantes e similares nos valores de 1-RM para o leg press 45º (TRAD = 25,9%; CP = 25,9%; DS = 24,9%) e cadeira extensora (TRAD = 16,6%; CP = 16,4%; DS = 17,1%). O AP e o CF aumentaram significantemente e de maneira similar para todos os protocolos (TRAD = 10,6% e 8,9%, respectivamente; CP = 11,0% e 8,9%, respectivamente; DS = 10,3% e 9,1%, respectivamente). Conclusão: Os sistemas PC e DS não promovem maiores ganhos em força, massa muscular ou arquitetura muscular comparado ao treinamento de força tradicional.FAPESP: 2015/16090-

GPR56 mRNA Expression Is Modulated by Acute and Chronic Training Variable Manipulations in Resistance-Trained Men

Background: Skeletal muscle adaptations are affected by resistance training (RT)-induced acute and chronic transcriptional responses. An under-explored gene target involved in mechanotransduction is the expression of the G protein-coupled receptor 56 (GPR56). However, studies investigating the acute and chronic effects of RT manipulations on GPR56 mRNA are scarce. Methods: Twenty subjects had each leg randomly assigned to a standard ((CON) no specific manipulation) or a variable RT (manipulations in load, volume, muscle action, and pause in a session-by-session fashion (VAR)). GPR56 mRNA expression was assessed before and after 16 training sessions (chronic effect) and 24 h after a 17th session (acute effect). Results: Acute GPR56 mRNA expression increased at 24 h (p < 0.01) without differences between CON and VAR (p > 0.05). No differences were found in GPR56 mRNA expression when comparing each VAR condition (load vs. sets vs. eccentric actions vs. pause) nor with CON at 24 h (p > 0.05). Chronic GPR56 mRNA expression increased at Post compared with Pre (p < 0.02) for VAR only, with a tendency (p = 0.058) toward higher expression for VAR as compared with CON. Conclusion: GPR56 mRNA expression is acutely and chronically modulated by RT. Additionally, chronic GPR56 mRNA expression is modulated by RT variable manipulations

Respostas neuromorfológicas referentes a um protocolo de treino resistido com ênfase na ação muscular isométrica

Neuromorphological responses due to a training protocol with emphasis in isometric muscular actionAim: The objective of this research was to investigate the potential of isometric muscle action in the routine of resistance training in relation to the increase in strength and muscle hypertrophy. Material and Methods: The study was with 12 men of 20.75 ± 1.22 years, 2.58 ± 0.79 trained years where 6 conducted structured workouts in 3 sets of 8 reps with 4 seconds of isometric at the beginning of each repetition concentric actions, 1 minute break between sets, 6x/weed, for 8 weeks (GE). Six subjects trained disregarding isometric emphasis, besides respecting the above conditions (GC). Were pre and post-experiment tests the Bench Press 1RM (SR) and 45 ° Leg Press (LP) and anthropometric test to determine body fat percentage (%G) and lean body mass (MCM). In the data we used the ANOVA with Tukey post-test, considering p<0.05. Discussion: We found an increase of force across joint amplitude and tending hypertrophy. Results: The data indicated a significant increase intra-group (p=0,049) in the 1RM test in the exercise of the GE SR (Pre: 105.00±10.18 Post: 119.67±10.15) at the end of eight weeks, plus an observable tendency to increase (p=0,98) MCM (Pre: 71.68± 5.03 Post: 73.34 ± 4.71). Conclusion: It is concluded that the use of isometrics with the dynamic efforts proved effective as the variable resistance training, enhancing the performance increase and eventually muscle hypertrophy.O objetivo desta pesquisa foi verificar o potencial da ação muscular isométrica na rotina do treinamento resistido em relação ao aumento da força e hipertrofia muscular. Material e Métodos: A pesquisa se deu com 12 homens de 20,75±1,22 anos, treinados a 2,58±0,79 anos, onde 6 realizaram treinos estruturados em 3 séries de 8 repetições, com 4 segundos de isometria no início das ações concêntricas de cada repetição, pausa de 1 minuto entre séries, 6x/semana,durante 8 semanas (GE). Seis sujeitos treinaram desconsiderando a ênfase isométrica, ademais respeitando as condições anteriores (GC).  Realizou-se pré e pós-experimento testes de 1RM no Supino Reto (SR) e Leg Press 45° (LP) e teste antropométrico para determinar percentual de gordura (%G) e massa corporal magra (MCM). No tratamento dos dados utilizou-se a análise de variância ANOVA com pós-teste de Tukey, considerando p<0,05. Resultados: Os dados indicaram significativo aumento intra-grupo (p=0,049) no teste de 1RM no exercício de SR no GE (Pré: 105,00±10,18Kg; Pós: 119,67±10,15Kg) ao final das oito semanas, além de uma observável tendência de aumento (p=0,98) da MCM (Pré: 71,68±5,03Kg; Pós: 73,34±4,71Kg). Discussão: Constatou-se aumento de força máxima nos MMSS e tendência à hipertrofia. Conclusão: Conclui-se que a utilização da isometria junto dos esforços dinâmicos mostrou-se eficaz como variável do treinamento resistido, potencializando o aumento de desempenho e, eventualmente, a hipertrofia muscular.