Efeitos da dor experimental no desempenho dos músculos flexores do cotovelo após oito semanas de treinamento de força: um estudo piloto / Effects of experimental pain on elbow flexor muscles performance after eight weeks of strength training: a pilot study

INTRODUÇÃO: O treinamento de força tem sido recomendado na reabilitação clínica, bem como no condicionamento físico de atletas. Não é incomum, em ambos os casos, a presença de dor durante a prática; no entanto, até o momento, não há informação consensual em relação aos efeitos da dor muscular aguda nas adaptações ao treinamento de força. OBJETIVO: O objetivo deste estudo piloto foi avaliar os efeitos da dor induzida experimentalmente na adaptação da força muscular após um período de treinamento de 8 semanas. MÉTODO: O estudo incluiu cinco voluntários saudáveis do sexo masculino e não treinados. Os participantes foram submetidos a um protocolo de treinamento de força (3x/semana durante 8 semanas) para os músculos flexores do cotovelo. A dor muscular aguda foi induzida no início de cada sessão de treinamento, por meio de infusão intramuscular de 2,5 ml de solução salina hipertônica (6%) no ventre do músculo bíceps braquial. A força dinâmica máxima (1RM) e a contração isométrica voluntária máxima (CIVM) foram medidas antes e após quatro e oito semanas de treinamento. RESULTADOS: A força dinâmica máxima aumentou, em média, 37,3% e 78,4% após quatro e oito semanas, respectivamente. Entretanto, pouca ou nenhuma diferença foi encontrada na CIVM (-1,7% e -3,0% após quatro e oito semanas, respectivamente). CONCLUSÃO: Após 24 sessões de treinamento de força, com dor muscular aguda induzida a cada sessão, voluntários saudáveis aumentaram sua capacidade de produzir força dinâmica máxima em mais de 75%; entretanto, a força isométrica apresentou apenas pequenas variações negativas.

INTRODUCTION: Strength training has been recommended in clinical rehabilitation, as well as in the physical conditioning of athletes. It is not uncommon, in both cases, the presence of pain during practice; however, to date, there is no consensual information about the effects of acute muscle pain on strength training adaptations. OBJECTIVE: The aim of this pilot study was to evaluate the effects of experimentally induced pain on muscle strength adaptation after an 8-week training period. METHOD: The study included five untrained, healthy male volunteers. Participants were submitted to a strength training protocol (3x/week for 8 weeks) for the elbow flexor muscles. Acute muscle pain was induced at the beginning of each training session through an intramuscular infusion of 2.5 ml of hypertonic saline (6%) into the biceps brachii muscle belly. Maximal dynamic strength (1RM) and maximal voluntary isometric contraction (MVIC) were measured at pre- and after four and eight weeks of training. RESULTS: Maximal dynamic strength increased, on average, 37.3% and 78.4% after four and eight weeks, respectively. However, little, if any, difference was found in MVIC (-1.7% and ­ 3.0% after four and eight weeks, respectively). CONCLUSION: After 24 strength training sessions, with acute muscle pain induced every session, healthy volunteers increased their ability to produce maximal dynamic strength by more than 75%; however, isometric strength presented only small negative changes.

Self-selected Rest Interval Improves Vertical Jump Postactivation Potentiation.

ABSTRACT: do Carmo, EC, De Souza, EO, Roschel, H, Kobal, R, Ramos, H, Gil, S, and Tricoli, V. Self-selected rest interval improves vertical jump postactivation potentiation. J Strength Cond Res 35(1): 91-96, 2021-This study compared the effects of self-selected rest interval (SSRI) and fixed rest interval (FRI) strategies on postactivation potentiation (PAP) in countermovement jump (CMJ) performance. Twelve strength-trained men (age: 25.4 ± 3.6 years; body mass: 78.8 ± 10.5 kg; height: 175 ± 7.0 cm; half-squat 1 repetition maximum: 188.7 ± 33.4 kg) performed 3 experimental conditions: (a) FRI: CMJ test; 4-minute rest interval; 5 repetition maximum (5RM) back squat; 4-minute rest interval; and CMJ test, (b) SSRI: CMJ test; 4-minute rest interval; 5RM back squat; SSRI; and CMJ test, and (c) control: CMJ test; 8-minute rest interval and CMJ test. In SSRI, subjects were instructed to rest until they felt fully recovered and able to exercise at maximal intensity based on the perceived readiness scale. Significant changes in pre-post CMJ performance were observed in the SSRI condition (38.2 ± 4.6 cm vs. 40.5 ± 4.4 cm; p = 0.08; confidence interval [CI]: 0.72-3.82 cm; effect size [ES] = 0.93). There were significant differences in post-CMJ performance when SSRI was compared with FRI (40.5 ± 4.4 cm vs. 37.7 ± 5.1 cm; p = 0.02; CI: 0.43-5.08; ES = 1.13) and control (40.5 ± 4.4 cm vs. 37.4 ± 5.7 cm; p = 0.01; CI: 0.66-5.61; ES = 1.35). The average rest interval length for the SSRI condition was 5:57 ± 2:44 min:sec (CI: 4:24-7:30). Our results suggest that the use of SSRI was an efficient and practical strategy to elicit PAP on CMJ height in strength-trained individuals.

Strength and power training improve skill performance in volleyball players

Abstract Aim: This study aimed to test the influence of functional improvements in volleyball skills performance. Methods: Twenty-eight amateur female volleyball players were assigned to Skill (S: n = 14, 19.5 ± 4.6 yrs; 169.7 ± 7.2 cm; 62.9 ± 12.7 kg) or Skill and Strength/Power (S+SP: n = 14; 18.6 ± 3.5 yrs; 169.7 ± 5.1 cm; 63.3 ± 9.2 kg). S+SP performed eight weeks of volleyball and conditioning training. S maintained only volleyball training. Functional variables (i.e. strength, power, and agility measures) and volleyball skills performance in a game-situation context were assessed before and after training. Results: 1-RM squat and bench press, time at modified agility T-test, peak power at bench throw and medicine-ball throw distance improved for the S+SP (p<0,05). S group increased only in medicine-ball throw distance (p<0.05). There were no differences between groups in the functional variables tested (p>0.05). The probabilities of a perfect set and an attack 'kill' in S+SP improved (¶>0.90). Changes from pre to post-training were higher in S+SP than in S for a perfect set, 'stuff block' and defense with displacement (¶>0.90). Conclusion: Our data suggest that functional improvements may positively affect volleyball skills performance. Although functional variables revealed only within-group changes, S+SP produced greater improvements in skill performance than S, supporting the use of conditioning training to improve volleyball performance.

Effect of eccentric action velocity on expression of genes related to myostatin signaling pathway in human skeletal muscle.

The aim of this study was to investigate the effects of an acute bout of eccentric actions, performed at fast velocity (210º.s-1) and at slow velocity (20º.s-1), on the gene expression of regulatory components of the myostatin (MSTN) signalling pathway. Participants performed an acute bout of eccentric actions at either a slow or a fast velocity. Muscle biopsy samples were taken before, immediately after, and 2 h after the exercise bout. The gene expression of the components of the MSTN pathway was assessed by real-time PCR. No change was observed in MSTN, ACTRIIB, GASP-1 or FOXO-3a gene expression after either slow or fast eccentric actions (p > 0.05). However, the MSTN inhibitors follistatin (FST), FST-like-3 (FSTL3) and SMAD-7 were significantly increased 2 h after both eccentric actions (p < 0.05). No significant difference between bouts was found before, immediately after, or 2 h after the eccentric actions (slow and fast velocities, p > 0.05). The current findings indicate that a bout of eccentric actions activates the expression of MSTN inhibitors. However, no difference was observed in MSTN inhibitors' gene expression when comparing slow and fast eccentric actions. It is possible that the greater time under tension induced by slow eccentric (SE) actions might compensate the effect of the greater velocity of fast eccentric (FE) actions. Additional studies are required to address the effect of eccentric action (EA) velocities on the pathways related to muscle hypertrophy.

Blood flow restriction increases metabolic stress but decreases muscle activation during high-load resistance exercise.

INTRODUCTION: We investigated differences in metabolic stress (lactate) and muscle activation (electromyography; EMG) when high-load resistance exercise (HL) is compared with a condition in which blood flow restriction (BFR) is applied during the exercise or during the rest interval. METHODS: Twelve participants performed HL with BFR during the intervals (BFR-I), during the set (BFR-S), and without BFR. Each condition consisted of 3 sets of 8 repetitions with knee extension at 70% of 1-repetition maximum. Lactate and root mean square (RMS) from the surface EMG of the vastus lateralis were calculated. RESULTS: Lactate increased in all protocols but was higher with BFR-I than with BFR-S and HL. RMS decreased under all conditions, with a larger effect size in BFR-I (1.47) than in BFR-S (0.66) and HL (0.59). DISCUSSION: BFR-I increases lactate, possibly as a result of reduced restoration of ATP. Muscle activation seems to be impacted by mechanical stress but may be reduced by metabolic stress. Muscle Nerve 57: 107-111, 2018.

Efeito da ordem dos exercícios de força sobre o volume, o lactato e o desempenho / Effect of the order of strength exercises on volume, lactate and performance / Efecto de la orden de los ejercicios de fuerza en el volumen, lactato y rendimiento

RESUMO Introdução: A alternância entre segmentos corporais para prescrição do treinamento de força (TF) é amplamente utilizada, entretanto seus efeitos permanecem desconhecidos. Objetivo: Verificar o efeito agudo da manipulação da ordem dos exercícios do TF, alternando segmentos corporais, sobre a força dinâmica máxima (1 RM) de membros inferiores (MMII) e superiores (MMSS), a concentração de lactato sanguíneo [La], a percepção subjetiva de esforço (PSE) e o volume total de treino (VT). Métodos: Dezoito homens (23,1 ± 3,8 anos; 78,4 ± 8,6 kg; 1,72 ± 0,06 m) executaram três condições de TF: condição A (supino reto, desenvolvimento, rosca Scott, meio-agachamento, leg press, cadeira extensora); condição B (meio-agachamento, leg press, cadeira extensora, supino reto, desenvolvimento, rosca Scott) e condição C (supino reto, meio-agachamento, desenvolvimento, leg press, rosca Scott e cadeira extensora). Os exercícios foram executados com três séries de 10 RM. Os testes de 1 RM para MMII e MMSS foram realizados nas semanas iniciais e após as condições experimentais. As coletas de sangue foram feitas no repouso [T0], imediatamente após [IA], 3 [T3] e 5 minutos [T5] após cada condição. A PSE de MMSS, MMII e geral, e o VT foram mensurados ao final de cada condição. Resultados: A 1 RM foi reduzida depois da sessão em todas as condições tanto para MMSS (A = -19,4%; B = -23,0%; C = -22,8%) quanto para MMII (A = -16,2%; B = -15,3%; C = -16,1%) sem diferença entre condições. A PSE apresentou resultados similares entre as condições (Condição A = 8,4; Condição B = 8,7; Condição C = 8,7). Houve aumento significante no La no momento T3 da condição C comparado com as outras condições: (C = 7,29 mmol.L-1; A = 6,60 mmol.L -1; B = 6,51 mmol.L-1) (p < 0,0001). O VT na condição C (16.169,4 ± 2.562,5 kg) foi superior às condições A (13.222,2 ± 2.010,4 kg) e B (13.989,8 ± 2.223,4 kg) (p < 0,0001). Conclusão: Os resultados sugerem que somente o VT e a demanda metabólica foram mais afetados pela ordem dos exercícios.

ABSTRACT Introduction: The alternation between body segments for prescription of strength training (ST) is widely used; however, its effects remain unknown. Objective: To verify the acute effect of the manipulation of the order of ST exercises, alterna-ting body segments, on the maximum dynamic force (1 RM) of lower limbs (LL) and upper limbs (UL), blood lactate [La] concentration, subjective perception of effort (SPE) and the total training volume (TV). Methods: Eighteen men (23.1±3.8 years; 78.4±8.6 kg; 1.72±0.06 m) performed three ST conditions: condition A: (bench press, shoulder press, preacher arm curl, half squat, leg press, leg extension); condition B (half squat, leg press, leg extension, bench press, shoulder press, preacher arm curl) and condition C (bench press, half squat, shoulder press, leg press, preacher arm curl, leg extension). The exercises were performed in three sets of 10 RM. The 1 RM tests for LL and UL were performed in the initial weeks and after the experimental conditions. Blood samples were taken at rest [T0], immediately after [IA], 3 [T3], and 5 minutes [T5] after each condition. SPE of UL, LL, and general, and VT were measured at the end of each condition. Results: The 1 RM was reduced after the session in all conditions for both UL (A = -19.4%, B = -23.0%, C = -22.8%) and LL (A = -16.2 %, B = -15.3%, C = -16.1%) with no difference between conditions. The SPE presented similar results between the conditions (Condition A=8.4, Condition B=8.7, Condition C=8.7). There was a significant increase in La at time T3 of condition C compared to the other conditions: (C=7.29 mmol.L-1, A=6.60 mmol.L-1, B=6.51 mmol.L-1) (p<0.0001). The TV in condition C (16,169.4 ± 2,562.5 kg) was higher than conditions A (13,222.2 ± 2,010.4 kg) and B (13,989.8 ± 2223.4 kg) (p<0.0001). Conclusion: The results suggest that only TV and the metabolic demand were more affected by the order of exercises.

RESUMEN Introducción: La alternancia entre los segmentos del cuerpo para la prescripción de entrenamiento de fuerza (EF) es ampliamente utilizada, pero siguen desconocidos sus efectos. Objetivo: Evaluar el efecto agudo de la manipulación de la orden de los ejercicios de EF, alternando segmentos del cuerpo, en la fuerza máxima (1 RM) de las extremidades inferiores (EI) y superiores (ES), la concentración del lactato (La) en la sangre, la percepción subjetiva del esfuerzo (PSE) y el volumen de entrenamiento (VE). Métodos: Dieciocho hombres (23,1 ± 3,8 años; 78,4 ± 8,6 kg; 1,72 ± 0,06 m) realizaron tres condiciones de EF: Condición A (press de banca, press de hombros, rosca Scott, media sentadilla, prensa de piernas, extensión de la pierna); Condición B (media sentadilla, prensa de piernas, extensión de la pierna, press de banca, press de ombros, rosca Scott) y Condición C (press de banca, media sentadilla, press de hombros, prensa de piernas, rosca Scott, y extensión de la pierna). Los ejercicios se realizaron con tres series de 10 RM. Las pruebas de 1 RM de las EI y ES se llevaron a cabo en las primeras semanas y después de las condiciones experimentales. Las muestras de sangre fueron tomadas en reposo [T0] inmediatamente después [IA], 3 [T3] y 5 minutos [T5] después de cada condición. La PSE, de ES, EI y general y VE se midieron al final de cada condición. Resultados: La 1 RM se redujo después de la sesión en todas las condiciones para ES (A = -19,4%; B = -23,0%; C = -22,8%) y EI (A = -16,2%; B = -15,3%; C = -16,1%), sin diferencia entre las condiciones. La PSE mostró resultados similares entre las condiciones (Condición A = 8,4, Condición B = 8.7, Condición C = 8,7). Hubo un aumento significativo en La en el momento T3 de la condición C en comparación con las otras condiciones (C = 7,29 mmol.L-1; A = 6,60 mmol.L-1, B = 6,51 mmol.L-1) (p < 0,0001). El VE en la condición C (16.169,4 ± 2.562,5 kg) fue superior a las condiciones A (13.222,2 ± 2.010.4 kg) y B (13.989,8 ± 2.223,4 kg) (p < 0,0001). Conclusión: Los resultados sugieren que solamente el VE y las demandas metabólicas fueron afectados por el orden de los ejercicios.

Risco de fadiga prematura, percepção subjetiva de esforço e estratégia de prova durante uma corrida de 10 km / Hazard score, rating of perceived exertion and pacing strategy during a 10 km running

O objetivo do estudo foi verificar as modificações na estratégia de prova frente às alterações do risco de fadiga prematura e da percepção subjetiva de esforço (PSE) em corredores durante uma corrida de 10 km. Participaram do estudo 55 corredores com tempo nos 10 km de 41:39 ± 3:52 min:s. A estratégia de prova e a PSE foram avaliadas a cada quilômetro. O risco de fadiga prematura foi determinado pelo produto entre a PSE e a distância restante de prova e a estratégia de prova foi determinada pela curva da velocidade e distância. A ANOVA de um caminho para medidas repetidas foi utilizada para determinar as diferenças na velocidade, PSE e risco de fadiga a cada quilômetro e entre a velocidade a cada quilômetro e a velocidade média da prova. O coeficiente de correlação de Pearson foi calculado entre a PSE e o risco de fadiga prematura com a velocidade. A velocidade do primeiro quilômetro foi 8,1% maior do que a média (p ≤ 0,001). A velocidade diminuiu gradualmente ao longo da prova, ocorrendo um novo aumento no décimo quilômetro. A PSE aumentou linearmente ao longo da prova e o risco de fadiga diminuiu significantemente após o terceiro quilômetro. Houve forte correlação negativa entre a PSE e a velocidade desenvolvida durante a prova (r = -0,80; p = 0,006). Foi observada uma correlação moderada negativa entre o risco de fadiga prematura e a velocidade (r = -0,57; p = 0,04). Com isso, os achados do presente estudo sugerem que a PSE parece ter importante papel sobre os ajustes da velocidade ao longo da prova, sendo que o aumento da velocidade observado no último quilômetro pode estar associado ao baixo risco de fadiga prematura

The aim of the study was to verify the modifications on pacing strategy induced by the hazard score of premature fatigue and rated perceived exertion (RPE) in amateur runners during a simulated 10-km running. Fifty five amateur runners with the 10-km run time of 41:39 ± 3:52 min:s participated in the study. The pacing strategy and the RPE were analyzed each kilometer. The hazard score of premature fatigue was expressed as the product of RPE by the remaining distance of the running. An ANOVA one-way for repeated measures was applied to determine possible statistical differences in speed, RPE and hazard score at each kilometer or the running speed differences at each kilometer and the average running speed. Pearson's product moment correlations were calculated between RPE and hazard of premature fatigue and running speed. The speed in the first kilometer was 8.1% higher than the average speed (p ≤ 0.001). There was a progressive decrease in speed during the running with an increment near the last kilometer. The RPE increased linearly until the end of the running and the hazard score of premature fatigue significantly decreased after the third kilometer. During the running there was a strong negative correlation between speed and RPE (r = -0.80; p = 0.006). It was also observed a moderate negative correlation between speed and hazard score of premature fatigue (r = -0.57; p = 0.04). Thus, our results suggested the important role of RPE on speed adjustment during a 10-km running and the increase of running speed near the end of the race seems to be associated to the lower score of hazard of premature fatigue

Effects of concurrent strength and endurance training on genes related to myostatin signaling pathway and muscle fiber responses.

Concurrent training (CT) seems to impair training-induced muscle hypertrophy. This study compared the effects of CT, strength training (ST) and interval training (IT) on the muscle fiber cross-sectional area (CSA) response, and on the expression of selected genes involved in the myostatin (MSTN) signaling mRNA levels. Thirty-seven physically active men were randomly divided into 4 groups: CT (n = 11), ST (n = 11), IT (n = 8), and control group (C) (n = 7) and underwent an 8-week training period. Vastus lateralis biopsy muscle samples were obtained at baseline and 48 hours after the last training session. Muscle fiber CSA, selected genes expression, and maximum dynamic ST (1 repetition maximum) were evaluated before and after training. Type IIa and type I muscle fiber CSA increased from pre- to posttest only in the ST group (17.08 and 17.9%, respectively). The SMAD-7 gene expression significantly increased at the posttest in the ST (53.9%) and CT groups (39.3%). The MSTN and its regulatory genes ActIIb, FLST-3, FOXO-3a, and GASP-1 mRNA levels remained unchanged across time and groups. One repetition maximum increased from pre- to posttest in both the ST and CT groups (ST = 18.5%; CT = 17.6%). Our findings are suggestive that MSTN and their regulatory genes at transcript level cannot differentiate muscle fiber CSA responses between CT and ST regimens in humans.

Análise do desempenho em atletas de elite no "Ironman" Brasil entre os anos de 2003 a 2010 / Performance analysis of elite Brazil-Ironman athletes from 2003 to 2010

O objetivo do presente estudo foi analisar a evolução no desempenho no "Ironman" Brasil entre os anos de 2003 a 2010. Adicionalmente, verificamos qual modalidade apresentou maior influência sobre o desempenho final na prova. Foram analisados os 10 primeiros colocados da categoria elite masculino de cada ano avaliado. As diferenças entre os tempos foram analisadas por ANOVA, seguida por "post-hoc" de Tukey. O coeficiente de correlação de Pearson foi empregado para investigar a associação entre o desempenho total e o desempenho nas diferentes modalidades isoladas. Os resultados mostraram não ter havido evolução no desempenho ao longo dos anos, sendo observada grande variação nos resultados. Foi observada, ainda, correlação entre o tempo de prova no ciclismo e o tempo total (r = 0,82; p < 0,01), sendo que o atleta com melhor tempo no ciclismo foi, também, o campeão da prova em 75% das vezes. Por fim, concluímos que não houve evolução no desempenho ao longo dos anos analisados. Adicionalmente, o ciclismo parece ser a modalidade determinante para o sucesso do atleta no "Ironman" Brasil.

The aim of this study was to analyze the performance evolution on the Brazil-Ironman from 2003 to 2010. Additionally, we verified which of the modalities were the most influential on the overall performance. The first ten athletes for each year in the ELITE male category were analyzed. The differences between the racing times were analyzed by ANOVA, followed by Tukey post-hoc test. Pearson's correlation coefficient was utilized to investigate the association between races performance and the performance in each one of the different modalities. The results showed that there was no performance evolution over the years and a great variation in racing times was observed. We have found a important correlation between cycling performance and race time (r = 0.82; p < 0.01) and the fastest athlete in cycling was the Brazil-Ironman champion in 75% of the analyzed years. Thus, it was concluded that there was no evolution in race time over the analyzed years. Additionally, the cycling might be the most influential modality for athletes' success in Brazil-Ironman.

Comparação de inibições medulares entre indivíduos com doença de Parkinson e saudáveis / Comparison of spinal inhibitions between parkisonian and helathy individuals

O objetivo do presente estudo foi comparar os níveis de inibição pré-sináptica (IPS) e inibição recíproca (IR) entre indivíduos com Doença de Parkinson e saudáveis e, a correlação entre essas inibições e a rigidez muscular e a severidade clínica de indivíduos com Doença de Parkinson (avaliadas através da Escala Unificada de Avaliação da Doença de Parkinson). Foram avaliados 11 indivíduos nos estágios 2 e 3 da doença e 13 indivíduos saudáveis pareados pela idade. A IPS foi menor em indivíduos com Doença de Parkinson (31,6%) do que em saudáveis (67,1%) (p = 0,02). A IR não diferiu entre indivíduos com Doença de Parkinson (26,9%) e saudáveis (27,6%) (p = 0,91). Adicionalmente, não foram detectadas correlações entre os níveis de IPS com a rigidez e a severidade clínica (p > 0,05). Portanto, mecanismos inibitórios não explicam totalmente a rigidez muscular e a severidade clinica da doença. Alterações entre ativação de músculos agonistas e antagonistas parecem estar relacionadas a influências supraespinhais anormais nos mecanismos espinhais decorrentes da doença...

The purposes of the present study were to compare presynaptic inhibition (PI) and disynaptic reciprocal inhibition (DRI) levels between parkinsonians and healthy individuals and to verify the correlation of such inhibitions with muscle rigidity and clinical severity (assessed by the Unified Parkinson Disease Rating Scale). We evaluated 11 parkinsonians in stages 2 and 3 of the disease and 13 healthy individuals matched for age. The PI was significant lower in parkinsonians (31.6%) than in healthy individuals (67.1%) (p = 0.02). The DRI did not differ between parkinsonians (26.9%) and healthy individuals (27.6%) (p = 0.91). Furthermore, no significant correlation was observed between PI with muscle rigidity and clinical severity (p > 0.05). Therefore, inhibitory mechanisms do not fully explain the cause of muscle rigidity and clinical severity of parkinsonians. Changes between the activation of agonist and antagonist muscles seem to be caused by abnormal supraspinal influence on spinal mechanisms...

O treinamento de força com e sem o uso da plataforma vibratória é capaz de modular a variabilidade da frequência cardíaca em repouso? / Strength training with and without a vibration platform is capable to modulate heart rate variability?

Esse trabalho comparou a variabilidade da frequência cardíaca (VFC) de repouso antes e após 10 semanas de treinamento de força de grupos que usaram e não usaram a plataforma vibratória. Dezessete homens saudáveis foram divididos nos grupos treinamento de força convencional (TF) ou treinamento de força sobre a plataforma vibratória a frequência de 30 Hz (TF+V30). As mensurações do desempenho de força dinâmica máxima (1-RM) no exercício meio agachamento e da VFC de repouso foram feitas antes e após o programa de treinamento. Ambos os grupos tiveram aumento significante da força no período pós (de 15,1% no grupo TF e de 16,4% no grupo TF+V30), no entanto esse aumento se alterou na mesma magnitude para os dois grupos, não havendo diferença entre eles no desempenho de 1-RM nos períodos pré e pós-treinamento. Não foi observada diferença nas comparações entre os grupos e nas situações pré e pós-treinamento nas análises da VFC de repouso, no entanto a magnitude do effect size foi moderada (ES = 0,50-0,80) para algumas variáveis (intervalo R-R, desvio-padrão da média de todos os intervalos R-R - SDNN, raiz quadrada da média dos quadrados das diferenças entre os intervalos R-R sucessivos - RMSSD, componente de baixa frequência ajustada por meio de logarítmico - InLF e componente de alta frequência ajustada por meio de logarítmico - InHF) no grupo TF+V30 após o período de treinamento. Conclui-se que 10 semanas de treinamento de força com e sem a presença da vibração proporcionou aumento semelhante no desempenho de 1-RM em ambos os grupos e, embora o estímulo adicional da vibração tenha dado indícios de maior atividade vagal analisado por meio do ES, nenhum dos grupos apresentou alteração significante da VFC.

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.

Efeito agudo dos exercícios de flexibilidade no desempenho de força máxima e resistência de força de membros inferiores e superiores / Acute effect of stretching exercises on upper and lower limbs maximum strength and strength endurance performance

Este estudo verificou o efeito agudo dos exercícios de flexibilidade estática (EFlex) no desempenho de força máxima (FM) e de resistência de força (RF) em membros inferiores e superiores. Treze voluntários participaram do estudo e foram submetidos a testes de FM e RF (70% 1RM) nos exercícios supino e agachamento precedidos ou não de EFlex. O teste T pareado foi utilizado para comparação das médias nas duas condições. Os EFlex diminuíram a FM no agachamento (141,2±34,2 vs 132±34,9kg; p=0,007) e no supino (77,5±21,7 vs 71,7±17,7kg p=0,04). A RF no agachamento não sofreu efeito dos EFlex (16,2±5,7 vs 16,3±6,8 repetições p=0,48), porém, no supino a RF apresentou diminuição significante (11,7±4,8 vs 9,9±5,1 repetições; p=0,008). Portanto, os EFlex reduziram a FM nos membros inferiores e superiores e a RF somente nos membros superiores. Essa diferença na RF estaria relacionada ao volume de exercícios de flexibilidade pelo tamanho do grupo muscular.

This study investigated the acute effect of static stretching exercises (SSE) on maximum strength (MS) and strength endurance (SE) performance in lower and upper limbs. Thirteen volunteers participated in the study and were submitted to MS and SE (70% 1RM) tests in the bench press and squat exercises with or without SSE. The paired T test showed that the SSE decreased MS in the squat (141.2±34.2 vs 132±34.9kg, p=0.007) and in the BP (77.5±21.7 vs 71.7±17.7kg p=0.04). Squat SE was not affected by SSE (16.2±5.7 vs 16.3±6.8 repetitions p=0.48). On the other hand, bench press SE decreased significantly after SSE (11.7±4.8 vs 9.9±5.1 repetitions p=0.008). Therefore, SSE impaired MS performance on upper and lower limbs but SE was affected only on upper limbs. This difference in SE may be related to the stretching exercises volume applied to the size of each muscle group.

Estratégia de corrida em média e longa distância: como ocorrem os ajustes de velocidade ao longo da prova? / La estratégia de la carrera del media y larga distancia: como se producen los ajustes de velocidad a lo largo de la carrera? / Pacing strategy in middle and long distance running: how are velocities adjusted during the race?

A estratégia de corrida tem sido apontada como um fator decisivo para o sucesso do atleta. Durante corridas de média e longa duração, a melhor estratégia será aquela capaz de poupar as "reservas fisiológicas", permitindo ao atleta terminar a prova no menor tempo possível. O controle da estratégia de corrida parece ser influenciado por fatores fisiológicos e psicológicos, que são ajustados constantemente durante a corrida, permitindo ao atleta determinar a intensidade do esforço. Diversas variáveis fisiológicas têm sido relacionadas aos ajustes da estratégia de corrida, no entanto, os resultados observados são controversos e foco de grandes discussões. Assim, a presente revisão tem como objetivo propiciar aos profissionais do esporte um melhor entendimento de questões como: 1) quais as melhores estratégias adotadas para determinado tipo de prova?; 2) como os ajustes da estratégia de corrida são realizados?; e 3) quais variáveis fisiológicas influenciam no controle da estratégia de corrida?.

The pacing strategy has been shown as an important factor for athletes' performance. During middle and long distance races, the best pacing strategy will be able to maintain a "physiological reserve" and to allow the athlete to run in his/her best time. It should be mentioned that the pacing strategy can be altered by physiological and psychological factors. These factors are frequently adjusted throughout the race and they will be used to control runner's pace. Several physiological variables have been suggested to have an important role in pacing strategy control. However, there is still controversial findings among the studies. Thus, the aim of this review was provide a better understanding about some questions such as: 1) what is the best pacing strategy for a specific race?; 2) how pacing strategy is controlled by the runner?; and 3) how physiological variables can induce changes on pacing strategy?.

La estrategia de la carrera ha sido identificada como un factor decisivo para el éxito del atleta. Durante las carreras de médio y largo plazo, la mejor estrategia es aquella que puede salvar a la "reserva fisiológica" que permite al atleta terminar la carrera en el menor tiempo posible. El control de la estrategia de carrera parece estar influenciada por algunos factores fisiológicos y psicológicos, que se ajustan com frecuencia durante la carrera, lo que permite al atleta determinar la intensidad del esfuerzo. Muchas de las variables fisiológicas se han relacionadas con los ajustes de la estrategia de carrera, sin embargo, los resultados observados son controvertidos y foco de muchos debates. Por lo tanto, esta revisión tiene como objetivo proporcionar a los profesionales del deporte una mejor comprensión de temas tales como: 1) cuáles son las mejores estrategias adoptadas para un tipo particular de prubea?; 2) cómo los ajustes de estrategia de prubea se hacen?; y 3) las variables fisiológicas que influyen en el control de la estrategia de carrera?.

Effects of strength and power training on neuromuscular adaptations and jumping movement pattern and performance.

This study aimed at comparing the effects of strength and power training (ST and PT) regimens on neuromuscular adaptations and changes on vertical jump performance, kinetics, and kinematics parameters. Forty physically active men (178.2 ± 7.0 cm; 75.1 ± 8.6 kg; 23.6 ± 3.5 years) with at least 2 years of ST experience were assigned to an ST (n = 14), a PT (n = 14), or a control group (C; n = 12). The training programs were performed during 8 weeks, 3 times per week. Dynamic and isometric maximum strength, cross-sectional area, and muscle activation were assessed before and after the experimental period. Squat jump (SJ) and countermovement jump (CMJ) performance, kinetics, and kinematics parameters were also assessed. Dynamic maximum strength increased similarly (p < 0.05) for the ST (22.8%) and PT (16.6%) groups. The maximum voluntary isometric contraction increased for the ST and PT groups (p < 0.05) in the posttraining assessments. There was a main time effect for muscle fiber cross-sectional area (p < 0.05), but there were no changes in muscle activation. The SJ height increased, after ST and PT, because of a faster concentric phase and a higher rate of force development (p < 0.05). The CMJ height increased only after PT (p < 0.05), but there were no significant changes in its kinetics and kinematics parameters. In conclusion, neuromuscular adaptations were similar between the training groups. The PT seemed more effective than the ST in increasing jumping performance, but neither the ST nor the PT was able to affect the SJ and the CMJ movement pattern (e.g., timing and sequencing of joint extension initiation).

Strength training with blood flow restriction diminishes myostatin gene expression.

PURPOSE: The aim of the study was to determine whether the similar muscle strength and hypertrophy responses observed after either low-intensity resistance exercise associated with moderate blood flow restriction or high-intensity resistance exercise are associated with similar changes in messenger RNA (mRNA) expression of selected genes involved in myostatin (MSTN) signaling. METHODS: Twenty-nine physically active male subjects were divided into three groups: low-intensity (20% one-repetition maximum (1RM)) resistance training (LI) (n = 10), low-intensity resistance exercise associated with moderate blood flow restriction (LIR) (n = 10), and high-intensity (80% 1RM) resistance exercise (HI) (n = 9). All of the groups underwent an 8-wk training program. Maximal dynamic knee extension strength (1RM), quadriceps cross-sectional area (CSA), MSTN, follistatin-like related genes (follistatin (FLST), follistatin-like 3 (FLST-3)), activin IIb, growth and differentiation factor-associated serum protein 1 (GASP-1), and MAD-related protein (SMAD-7) mRNA gene expression were assessed before and after training. RESULTS: Knee extension 1RM significantly increased in all groups (LI = 20.7%, LIR = 40.1%, and HI = 36.2%). CSA increased in both the LIR and HI groups (6.3% and 6.1%, respectively). MSTN mRNA expression decreased in the LIR and HI groups (45% and 41%, respectively). There were no significant changes in activin IIb (P > 0.05). FLST and FLST-3 mRNA expression increased in all groups from pre- to posttest (P < 0.001). FLST-3 expression was significantly greater in the HI when compared with the LIR and LI groups at posttest (P = 0.024 and P = 0.018, respectively). GASP-1 and SMAD-7 gene expression significantly increased in both the LIR and HI groups. CONCLUSIONS: We concluded that LIR was able to induce gains in 1RM and quadriceps CSA similar to those observed after traditional HI. These responses may be related to the concomitant decrease in MSTN and increase in FLST isoforms, GASP-1, and SMAD-7 mRNA gene expression.

Creatine but not betaine supplementation increases muscle phosphorylcreatine content and strength performance.

We aimed to investigate the role of betaine supplementation on muscle phosphorylcreatine (PCr) content and strength performance in untrained subjects. Additionally, we compared the ergogenic and physiological responses to betaine versus creatine supplementation. Finally, we also tested the possible additive effects of creatine and betaine supplementation. This was a double-blind, randomized, placebo-controlled study. Subjects were assigned to receive betaine (BET; 2 g/day), creatine (CR; 20 g/day), betaine plus creatine (BET+CR; 2+20 g/day, respectively) or placebo (PL). At baseline and after 10 days of supplementation, we assessed muscle strength and power, muscle PCr content, and body composition. The CR and BET+CR groups presented greater increase in muscle PCr content than PL (p=0.004 and p=0.006, respectively). PCr content was comparable between BET versus PL (p=0.78) and CR versus BET+CR (p=0.99). CR and BET+CR presented greater muscle power output than PL in the squat exercise following supplementation (p=0.003 and p=0.041, respectively). Similarly, bench press average power was significantly greater for the CR-supplemented groups. CR and BET+CR groups also showed significant pre- to post-test increase in 1-RM squat and bench press (CR: p=0.027 and p<0.0001; BET+CR: p=0.03 and p<0.0001 for upper- and lower-body assessments, respectively) No significant differences for 1-RM strength and power were observed between BET versus PL and CR versus BET+CR. Body composition did not differ between the groups. In conclusion, we reported that betaine supplementation does not augment muscle PCr content. Furthermore, we showed that betaine supplementation combined or not with creatine supplementation does not affect strength and power performance in untrained subjects.

Efeito da familiarização na estabilização dos valores e 1RM para homens e mulheres / Effect of familiarization on the stabilization of 1RM values for men and women

O objetivo deste estudo foi verificar o número de sessões de familiarização necessárias para estabilização da carga do teste de uma repetição máxima (1RM) no exercício agachamento em homens e mulheres. Oito homens (25 ± 4 anos) e oito mulheres (20 ± 1anos) foram submetidos a cinco sessões experimentais. ANOVA e plotagem de Bland-Altman foram utilizadas para comparar a carga de 1RM entre as sessões (p<0,05). A estabilização da carga ocorreu na quarta sessão para os homens e na terceira para as mulheres, com aumentos significantes da força absoluta e relativa da primeira à quarta (17kg e 19%) e da primeira à terceira (9kg e 14%) sessões, respectivamente. Porém, não houve diferença significante na força relativa entre os gêneros. De acordo com nossos resultados, indivíduos inexperientes em treinamento de força atingem alta reprodutibilidade ao teste de 1RM no exercício agachamento, após realizar três a quatro sessões de familiarização.

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.

Diversidade e eficiência das dinâmicas de criação de espaço e grau de cooperação entre as equipes de basquetebol paulistas: efeito da faixa etária / Diversity and efficiency of the space creation dynamics and cooperation rate in basketball teams: age effect

O objetivo deste trabalho foi avaliar o efeito da experiência competitiva sobre as seguintes variáveis de desempenho: 1) diversidade das dinâmicas de criação de espaço (DCEs) no setor defensivo; 2) eficiência das DCEs (i.e., frequência de êxito/total de execuções); 3) grau de cooperação ofensiva (i.e. número de passes e assistências). Foram analisados 46 jogos do Campeonato Paulista Masculino de Basquetebol (i.e. pré-mini a adulto). Variáveis medidas: 1) DCEs realizadas, que precederam o término da posse de bola em finalização, falta ou erro; 2) eficiência das DCEs; 3) passes em um ataque; 4) assistências. A reprodutibilidade foi testada pelo teste Kappa, tendo apresentado índices entre 0,78-0,85. A diversidade das DCEs não apresentou diferença significante para nenhuma classe de DCE entre todas as faixas etárias. Na análise intra-faixa etária, contra defesa individual, verificou-se significante predomínio de Desmarque com Bola com Drible para os mais jovens (pré-mini a infantil) e de Bloqueio Direto para os mais velhos (juvenil e adulto). Contra defesa zona, Desmarque sem Bola foi significantemente mais frequente em todas as faixas etárias em relação às demais DCEs, exceto Desmarque com Bola com Drible. Não foi verificada diferença significante para nenhuma das DCEs quanto à eficiência entre todas as faixas etárias. Todas as faixas etárias apresentaram perfil semelhante quanto ao número de passes, assim como de assistências. Estes resultados contrariam a hipótese formulada que previa aumento da complexidade e diversificação das ações com o aumento da experiência competitiva dos jogadores. Estas evidências sugerem a necessidade de propostas metodológicas de ensino do jogo com foco no coletivo e na cooperação.

The aim of the present study was to evaluate the effect of competitive experience in the following performance variables: 1) diversity of the Space Creation Dynamics (SCDs); 2) efficiency of the SCDs (i.e. successful SCDs/total amount of SCDs); 3) offensive cooperation (i.e. number of passes and assists). A total of 46 matches of all age goups (i.e. pré-mini to seniors) of the São Paulo state championship for men were analyzed. Measured/ calculated variables: 1) SCDs performed; 2) SCDs efficiency; 3) passes performed on ball possession; 4) assists performed. Researcher's reliability was tested in three moments with one week apart of each other (Kappa rates: 0.78-0.85). SCDs diversity presented no significant difference for any SCD class among all age groups. Intra-age analysis, against man-to-man defense, presented significant prevalence of "Desmarque com Bola com Drible" for younger players (pré-mini to infantil) and of "Bloqueio Direto" for older players (juvenil and seniors). Against zone defense, "Desmarque sem Bola" was significantly more frequent for all age groups in comparison to all others SCDs, except for "Desmarque com Bola com Drible". It was not observed a significant difference for efficiency of the SCDs at any age group. All age groups presented similar distribution regarding frequencies of number of passes and assists as well. These results contradicted the preliminary hypothesis, which expected an increase in complexity and diversity of actions paralleled with an increase in players' competitive expertise. These evidences suggest the need of cooperation and collective-focused teaching games methodology.

A fisiologia em educação física e esporte / The physiology in physical education and sport

A Fisiologia do Exercício, área de conhecimento derivada da Fisiologia, é caracterizada pelo estudo dos efeitos agudos e crônicos do exercício físico sobre as estruturas e as funções dos sistemas do corpo humano. Ela pode ser considerada uma das disciplinas mais tradicionais relacionadas à prática acadêmica e profissional da Educação Física e do Esporte em função da grande herança biológica destas áreas. Neste artigo, serão abordadas às linhas de pesquisa nessa área, a integração do conhecimento científico com a prática profissional e as perspectivas futuras da Fisiologia do Exercício.

Exercise Physiology is a sub discipline from the area of Physiology. It is characterized by the investigation of the acute and chronic effects of physical exercise on the structures and functions of the human body. Exercise Physiology can be considered one of the most traditional academic and professional sub disciplines of the Physical Education and Sport because of the biological heritage of these fields. In this paper, we are going to discuss the lines of investigation, the relationship between the scientific knowledge and professional practice, and the future perspectives for the Exercise Physiology.

Treinamento físico: considerações práticas e científicas / Physical training: scientific and practical considerations

O treinamento físico é uma importante área de atuação profissional da Educação Física e do Esporte. Ela tem por objetivo precípuo, a melhoria do desempenho físico-esportivo através da aplicação de um processo organizado e sistemático composto por exercícios físicos. Nos últimos anos, os progressos tecnológicos e nos métodos de investigação científica nas diferentes subáreas relacionadas ao treinamento físico trouxeram um avanço significativo na obtenção deste objetivo. Neste artigo será discutido, do ponto de vista acadêmico-científico e também da prática profissional, o estado da arte do conhecimento associado à avaliação do treinamento, ao controle da carga de treinamento, aos modelos de organização da carga de treinamento e ao desenvolvimento das capacidades motoras. Esperamos que ao final, o leitor possa ter um bom entendimento destes diferentes componentes, como eles contribuem para a modificação do desempenho motor e como aplicá-los para a elaboração, implementação, avaliação e reformulação de programas de treinamento físico.

Physical training is an important field of work for the Physical Education and Sport professional. Its main goal is to develop the physical capacity and sports performance of an individual by means of an organized and systematic application of physical exercises. In the past years, the technological progress in the scientific investigation within the different disciplines related to physical training have contributed a great deal towards the accomplishment of such goal. In this manuscript we discuss, from both an academic-scientific and from a practical application point-of-view, the state of the art of the knowledge associated with the physical training evaluation, loading control, loading scheming, and the development of physical abilities. Our goal is to provide a comprehensive overview of the different components of the physical training and how they contribute to the development of the physical performance as well as how to apply these concepts in the elaboration, implementation, and evaluation of physical training programs.