Effect of varied plyometric training in land and aquatic medium on anaerobic power of athletes / Efeito do treinamento pliométrico variado em meio terrestre e aquático na potência anaeróbia de atletas

ABSTRACT The aim of the present study was to find out the effect of varied plyometric training (land plyometric training, aqua plyometric training and weighted vest aqua-plyometric training) on anaerobic power of school athletes. A total of forty eight (n= 48) district level school athletes were randomly selected. All the subjects were divided into four equal groups: i) land plyometric training group (n=12), ii) aqua plyometric training group (n=12), iii) aqua-plyometric training with weighted vest group (n=12) and iv) control group (n=12). The varied plyometric training was intervened for fourteen weeks in the respective training groups. In the present study, anaerobic power was considered as the dependent variable, and it was measured by Margaria-Kalamen power test. To draw statistical inferences on anaerobic power among the groups in pre and post intervention conditions, ANCOVA was used, followed by Tukey's LSD post-hoc test. The significance of the means was tested at the 0.05 level. Different plyometric training groups improved significantly with respect to the control group in anaerobic power. Therefore, various plyometric training was found as an effective means for developing anaerobic power. A significant difference was also observed between the aqua-plyometric training with weighted vest group and land plyometric training group in anaerobic power. However, rest of the experimental groups didn't differ significantly. Aqua-plyometric training with weighted vest is a more effective training method than land plyometric training for improving the anaerobic power of the school athletes.

RESUMO O objetivo do presente estudo foi descobrir o efeito do treinamento pliométrico variado (treinamento pliométrico terrestre, treinamento aquapliométrico e treinamento aquapliométrico com colete ponderado) na potência anaeróbica de atletas escolares. Um total de quarenta e oito (n= 48) atletas escolares de nível distrital foram selecionados aleatoriamente. Todos os sujeitos foram divididos em quatro grupos iguais: i) grupo treinamento pliométrico terrestre (n=12), ii) grupo treinamento aquapliométrico (n=12), iii) grupo treinamento aquapliométrico com colete ponderado (n=12) e iv) grupo controle (n=12). O treino pliométrico variado foi intervencionado durante quatorze semanas nos respectivos grupos de treino. No presente estudo, a potência anaeróbia foi considerada como variável dependente e foi mensurada pelo teste de potência de Margaria-Kalamen. Para fazer inferências estatísticas sobre a potência anaeróbica entre os grupos nas condições pré e pós-intervenção, foi utilizada a ANCOVA, seguida do teste post-hoc de Tukey LSD. A significância das médias foi testada no nível 0,05. Diferentes grupos de treinamento pliométrico melhoraram significativamente em relação ao grupo controle na potência anaeróbica. Portanto, vários treinamentos pliométricos foram encontrados como um meio eficaz para o desenvolvimento da potência anaeróbica. Uma diferença significativa também foi observada entre o grupo de treinamento aquapliométrico com colete ponderado e o grupo de treinamento pliométrico terrestre na potência anaeróbica. No entanto, o resto dos grupos experimentais não diferiram significativamente. O treinamento aquapliométrico com colete ponderado é um método de treinamento mais eficaz do que o treinamento pliométrico terrestre para melhorar a potência anaeróbica dos atletas escolares.

An Analysis of Change on Alpine Skiers' Body Composition, Anaerobic Power, and Isokinetic Muscular Function between before and after Winter Season / 대한스포츠의학회지

PURPOSE: The purpose of this study was to investigate the changes on alpine skiers' body composition, anaerobic power, isokinetic knee strength and muscle balance ratio (hamstring to quadriceps [HQ] ratio) before and after winter season. METHODS: The subjects of this study was 22 elite alpine skier, aged 16–20 years. Participants were divided into two groups (male, 12; female, 10). The study conducts a periodization training program in the winter season for 4 months. The data processing of this study was analyzed by paired t-test, using SPSS 21.0 statistics program. RESULTS: There was significance on fat free mass in male group (p < 0.05); there was significance on anaerobic power and average power in female group (p < 0.01), and fatigue index significantly increased in male group (p < 0.05). There was significance on extension power of male group and flexion power of female group in 30°/sec. There was significance on extension power of both groups in 180°/sec (p < 0.05). There was significant increase on flexion power of male group in 240°/sec (p < 0.01). There was significant increase on H/Q% of female right side in 30°/sec (p < 0.01). There was significance on right side of both groups in 180°/sec (p < 0.05). There were significances on right and left side of both groups in 240°/sec (male, p < 0.01; female, p < 0.05). CONCLUSION: Therefore, this study suggests that the periodization training should be important to maintain and to develop seasonal condition of alpine skiers.

Predicción del tiempo en la prueba de 300 metros en patinadores juveniles de rendimiento / Time prediction in the 300 meter test of young performance skaters

El patinaje de velocidad es una disciplina competitiva de popularidad creciente; sin embargo, la evidencia científica disponible sobre regímenes de entrenamiento, de evaluación y de control es aún limitada. Por la naturaleza de la disciplina es frecuente el uso de pruebas de fuerza explosiva, para la valoración de los deportistas. El objetivo del presente estudio es predecir el rendimiento en la prueba de 300m, en patinadores de velocidad de categoría juvenil pista, de Bogotá, Colombia. Se evaluaron 50 patinadores (37 mujeres y 13 hombres), de la categoría juvenil. Se realizaron carreras de 300m, en la pista de un patinódromo y el tiempo fue cronometrado mediante un sistema de fotoceldas (Microgate Polifemo). Se determinó la altura de los saltos squat (SJ) y contra-movimiento (CMJ), con un sistema óptico de medición (OptoGait, Microgate). Se realizó una prueba de Wingate de 30s, utilizando un ciclo-ergómetro (Cyclus 2, RBM Elektronik-Automation). Se hicieron análisis bivariados y multivariados, utilizando el tiempo de la prueba de 300m, como variable dependiente. El análisis multivariado arrojó que la potencia media relativa (b = -1,163; se b = 0,326) y el salto desde sentadilla (b = -1,137; se b = 0,053) fueron las variables significativas (p<0,01), para predecir el tiempo en la prueba de 300 m (r² = 0,7). El salto squat y la potencia media relativa han mostrado ser pruebas predictoras del rendimiento en el tiempo de la prueba de 300m, en patinadores juveniles de Bogotá, Colombia.

Skating race is a competitive discipline of growing popularity, however, the available scientific evidence on training, evaluation and control systems is still limited. By the nature of the discipline, using explosive force tests for the evaluation of athletes is frequent. The objective of the present study is to predict performance in the 300m test of junior category speed skaters. 50 skaters (37 women and 13 men) from junior category were evaluated. 300m races were held on the track of a skating rink, and time was measured by a photocells system (Microgate Polyphemus). Height in squat and countermovement jumps were determined using an optical system (OptoGait, Microgate). 30 s Wingate test was performed in a cycle-ergometer (Cyclus 2-RBM Elektronik Automation). Bivariate and multivariate analyzes were performed setting 300m race time as a dependent variable. Multivariate analysis showed that average relative power (b=-1.163; se b= 0.326) and squat jump height (b= -1.137; se b= 0.053) were the significant variables (p<0.01) to predict the 300m test (r²= 0.7). The squat jump height and average relative power tests have shown to be predictive of performance in 300m test in junior skaters.

Effects of saddle height on performance and muscular activity during the wingate test / Efeitos da altura do selim no desempenho e na ativação muscular durante teste de wingate

ABSTRACT This study aimed to analyze the anaerobic performance and muscle activation during a supramaximal cycling test at three different saddle positions. Twelve competitive cyclists completed an incremental cycling test and three 30-s Wingate tests in three different saddle heights (reference, downward, and upward), in a random order, on different days. The saddle height was individually shifted downward and upward (seeing 2.5% of the distance from the pubic symphysis to ground) from the reference position. The electromyographic signal (EMG) data was obtained from the rectus femoris, vastus lateralis, biceps femoris (long head), and gastrocnemius lateralis in order to assess muscle activation during the entire test. The anaerobic variables and the EMG data were divided into six consecutive windows of 5-s. The EMG signals were normalized by the first 5-s window of the reference position to provide the percentage changes throughout the test. The results suggest that during a 30-s Wingate test small changes in saddle height result in greater peak power output (reference=1380±241 W; downward=1497±175 W, p=0.036; upward=1491±225 W, p=0.049) and greater activation period for vastus lateralis (reference=33.6%, downward=33.2%, upward=35.0%; p=0.001) in comparision to rectus femoris (reference=24.5%, downward=25.2%, upward=23.7%), biceps femoris (reference=20.7%, downward=20.8%, upward=19.9%), and gastrocnemius lateralis (reference=21.2%, downward=20.8%, upward=19.9%). The results suggest that small adjustments in saddle height may affect the force-length relationship of the muscles of the lower limb, and consequently their recruitment pattern and their ability to generate force.

RESUMO O presente estudo teve como objetivo analisar o desempenho anaeróbio e a ativação muscular durante um teste de ciclismo supramáximo em três diferentes alturas do selim. Doze ciclistas competitivos completaram um teste incremental em cicloergômetro e três testes de Wingate de 30 s em diferentes alturas do selim (referência, baixa e alta), de forma randomizada, em diferentes dias. A altura do selim foi alterada para baixo e para cima a partir da posição de referência usando como parâmetro o valor referente a (± 2,5%) da distância da sínfise púbica até o solo. O sinal eletromiográfico (EMG) foi obtido dos músculos reto femoral, vasto lateral, bíceps femoral (cabeça longa) e gastrocnêmio lateral. As variáveis anaeróbias e os dados de EMG foram divididos em seis janelas consecutivas de 5 s. Os sinals EMG foram normalizados pela primeira janela da posição de referência para estipular as mudanças percentuais ao longo do teste. Os resultados sugerem que durante o teste de Wingate de 30 s pequenas alterações na altura do selim resultam em aumento da potência pico (referência=1380±241 W; baixa=1497±175 W, p=0,036; alta=1491±225 W, p=0,049) e maior período de ativação percentual para o vasto lateral (referência=33,6%, baixa=33,2%, alta=35,0%; p=0,001) em relação ao reto femoral (referência=24,5%, baixa=25,2%, alta=23.7%), bíceps femoral (referência=20,7%, baixa=20,8%, alta=19,9%) e gastrocnêmio lateral (referência=21,2%, baixa=20,8%, alta=19,9%). Os resultados sugerem que pequenos ajustes na altura do selim podem afetar a relação força-comprimento e, consequentemente, a capacidade de gerar força e o padrão de recrutamento muscular dos membros inferiores.

Efeito da aprendizagem no desempenho de repetidos testes de Wingate / Learning effect in the performance in Wingate repeated tests / Efecto del aprendizaje nel desempeño de repetidas evaluaciones de Wingate

O objetivo do estudo foi verificar a existência do efeito aprendizagem nos resultados de repetidos testes de Wingate. Doze ciclistas foram submetidos a dois testes de Wingate (TW1 e TW2) com intervalo de uma semana. A resistência adicionada foi equivalente a 10% da massa corporal e as rotinas foram planejadas para reproduzir as mesmas condições em ambos os testes. Os resultados revelaram grande amplitude nos limites de concordância dos testes 1 e 2 em todas as variáveis, bem como diferenças significantes para Potência Média (PM), em valores absolutos (TW1: 579,7 ± 91,0 W vs TW2: 616,9 ± 102,2 W) e valores relativos (TW1: 8,3 ± 0,8 W/kg vs TW2: 8,8 ± 0,9 W/kg). A evidência demonstra a existência do efeito aprendizagem causando influência nos resultados da potência anaeróbica.

The purpose of this study was to verify the existence of learning effect in results of Wingate repeated tests. Twelve cyclists were submitted to two Wingate Tests (TW1 and TW2) with an interval of a week. The added resistance was equivalent to 10% of body mass, the routines were planned to reproduce the same conditions in both tests. Even though the high correlation (0,92), the results showed significant difference for Mean Power (PM), in absolute values (TW1: 579,7 ± 91,0 W vs TW2: 616,9 ± 102,2) and relative values, (TW1: 8,3 ± 0,8 W/kg vs TW2: 8,8 ± 0,9 W/kg) favoring the second test. The evidence demonstrated the existence of learning effect affecting results of anaerobic power.

El objetivo del estudio fue investigar la existencia del efecto del aprendizaje en los resultados de repetidas evaluaciones de Wingate. Doce ciclistas fueron sometidos a dos evaluaciones de Wingate (TW1 e TW2) con intervalo de una semana. La resistencia adicionada fue equivalente a 10% de la masa corporal y las rutinas fueron planeadas para reproducir las mismas condiciones en las dos evaluaciones. Mismo con la correlación de 0,92, los resultados revelaran diferencias significativas para la Potencia Media (PM) en valores absolutos (TW1: 579,7 ± 91,0 W vs TW2: 616,9 ± 102,2 W) y valores relativos (TW1: 8,3 ± 0,8 W/kg vs TW2: 8,8 ± 0,9 W/kg), favoreciendo la segunda evaluación. Eso demuestra la existencia del efecto del aprendizaje influyendo la potencia anaeróbica.

Suplementação de cafeína e indicadores de potência anaeróbia / Supplementation of caffeine and anaerobic power indicators

O objetivo foi verificar o efeito da suplementação de cafeína na potência anaeróbia intermitente em ciclistas treinados. Dez atletas foram submetidos a duas sessões experimentais em um modelo randomizado e duplo-cego. Em cada sessão, os participantes ingeriram aleatoriamente uma cápsula de cafeína (6 mg/kg) ou placebo, e, uma hora após realizaram dois testes de Wingate (T1, T2) para a determinação do desempenho anaeróbio, com um intervalo de 4 minutos entre si. A análise estatística, utilizado ANOVA para medidas repetidas, não revelou diferenças significativas entre os testes com cafeína e placebo. Na comparação intra-testes houve redução significativa apenas para a Potência Média (W) entre as sessões com cafeína (T1c: 673,6±59,5 vs T2c: 589,0±58,8). A ingestão oral aguda de cafeína não contribuiu para o aumento no desempenho anaeróbio intermitente, porém, a redução na potência média com o uso da cafeína, pode sugerir uma preferência do metabolismo para os ácidos graxos, o que seria desvantajoso durante esforços máximos intermitentes.

The aim was to investigate the effect of caffeine on anaerobic power intermittently trained cyclists. Ten athletes underwent two experimental sessions in a model randomized double-blind study. In each session, subjects ingested a random capsule caffeine (6 mg / kg) or placebo. One hour after, two tests Wingate were carried (T1, T2) for determining the anaerobic performance with 4 min of rest between each exercise bout. Statistical analysis used ANOVA for repeated measures revealed no significant differences between the caffeine and placebo trials. In comparing intra-tests was significantly reduced only to Mean Power (W) between sessions with caffeine (T1c: 673.6 ± 59.5 vs. T2c: 589.0 ± 58.8). The acute oral intake of caffeine did not contribute to the increase in intermittent anaerobic performance, however, the reduction in average power with the use of caffeine, may suggest a preference for fatty acid metabolism, which would be disadvantageous during intermittent maximal efforts.

Características aeróbias e anaeróbias de mesatenistas brasileiros treinados / Aerobic and anaerobic characteristics of Brazilian trained table tennis players

O objetivo deste estudo foi determinar, em mesatenistas bem treinados, as aptidões aeróbia e anaeróbia. Participaram do presente estudo oito mesatenistas brasileiros treinados do sexo masculino (18±2 anos). Os sujeitos foram submetidos a um teste incremental específico para determinação do consumo pico de oxigênio (VO2PICO), intensidade associada ao VO2PICO(iVO2PICO) e do ponto de compensação respiratório (PCR) e a dois testes de esforço repetitivo, sendo o teste de RAST e o índice anaeróbio alático (IAA), para determinação dos índices anaeróbios. O VO2PICO correspondeu a 50,5±4,4ml kg-1 min-1, a VO2PICO a 52,1±9,6 bolas min-1 e o PCR a 44,9±8,0 bolas min-1. No RAST, a potência pico (PP) e a potência média (PM) relativa corresponderam a 9,0±1,3W kg-1 e 7,0±0,9W kg-1, respectivamente, enquanto que o IAA foi 1,14±0,51 mM/m s-1. Esses valores de VO2PICO e dos parâmetros anaeróbios quando comparados a valores de outros esportes com raquetes caracterizaram que mesatenistas brasileiros treinados apresentam potência aeróbia moderada e potência anaeróbia é baixa.

The purposes of this study were to determine the aerobic conditioning and anaerobic conditioning in trained table tennis players. Eigth Brazilian male table tennis players (18±2 years) participated of the study. Subjects performed graded exercise test in specific procedure to measure peak oxygen uptake (VO2peak), intensity associated at VO2PEAK (iVO2PEAK) and respiratoty conpensation point (RCP), and two repeated-sprint abilit tests (i.e., RAST and alactic anaerobic índex (AAI)), which were considered as anaerobic parameters. VO2PEAK corresponded to 50.5±4.4ml kg-1 min-1 , iVO2PEAK to 52.1±9.6balls min-1 e o RCP 44.9±8.0balls min-1. Peak power (PP) and mean power (MP) relative to body mass (PPr and MPr, respectively) measured during RAST were 9.0±1.3W kg-1 and 7.0±0.9W kg-1, respectively, whereas AAI (i.e., ratio of blood lactate and average speed) was 1.14±0.51mM/m s-1. Thus, we can conclude that trained Brazilian table tennis players have moderated aerobic power, low anaerobic conditioning.

Composição corporal, limiar anaeróbio e consumo máximo de oxigênio de atletas de futsal: analise descritiva entre as posições / Body composition, anaerobic threshold and maximal uptake oxygen in athletes of futsal: descriptive analyses between the positions

o futsal é um esporte dinâmico e dependendo das movimentações do jogo, ocorre grande acúmulo de ácido láctico, tornando a capacidade e a potência aeróbia qualidades físicas essenciais na manutenção das intensas movimentações características desta modalidade. Objetivo: descrever as características da composição corporal, limiar anaeróbio e o consumo máximo de oxigênio nas diferentes posições do futsal. Materiais e métodos: participaram do estudo 22 atletas integrantes da seleção brasiliense de futsal, com idade entre 23 e 32 anos. A composição corporal com as variáveis: peso, estatura e dobras cutâneas foram feitas de acordo com os procedimentos descritos por Petroski, 1995. O VO2 máximo foi mensurado em esteira ergométrica com protocolo de rampa até atingir a fadiga voluntária. As trocas gasosas foram coletadas e medidas a cada ventilação. O limiar anaeróbio foi determinado com base nos equivalentes metabólicos de oxigênio e gás carbônico. A normalidade dos dados foi testada e utilizada a Estatística Descritiva e Analise de Variância com comparações múltiplas através do Bonferroni Post Hoc Test. O nível de significância p < 0,05 foi usado para apontar as diferenças significativas. As análises foram realizadas no programa SPSS 11.5. Resultados: os atletas apresentaram idade média de 26,9 ± 3,6 anos, massa corporal 72,7 ± 12,9kg, estatura 175,2 ± 6,9cm, gordura corporal 13 ± 5,7%, VO2 máximo 52,8 ± 6,4 ml/kg/min-1 e limiar anaeróbio 45,7 ± 5,7 ml/kg/min-1. Conclusão: a massa corporal dos alas foi menor que os goleiros e o VO2 máximo e o limiar anaeróbio dos alas foi superior aos goleiros.

Futsal is a dynamic sport and depending of movements of the game is large accumulation of lactic acid, making the capacity and aerobic power physical qualities essential to maintain the intense movement characteristics of this type modality. Objective: To describe the characteristics of body composition, anaerobic threshold and maximum oxygen consumption in the different positions of Futsal. Materials and Methods: Twenty two elite Brasilia athletes, with ages between 22 and 33 years old, participated in the study. Anthropometric measures with the variables weight, height and skinfolds were measured in accordance with Petroski, 1995 procedure. VO2 maximal was measured in treadmill with ramp protocol until voluntary fatigue. The gas exchange was collected and measures ventilation by ventilation. The anaerobic threshold was determinate on the basis of metabolic equivalents of oxygen and carbon dioxide. The normality of the data has been tested and used the descriptive statistics and analysis of variance with multiple comparisons Bonferroni Post Hoc Test. Value p < 0.05 was adopted to show the significant differences. The analyses were performed through the SPSS 11.5 program. Results: Athletes had a mean age of 26.9 ± 3.6 years, body mass 72.7 ± 12.9 kg, height 175.2 ± 6.9 cm, body fat, 13 ± 5.7%, VO2 maximal 52.8 ± 6.4 ml/kg/min-1 and anaerobic threshold 45.7 ± 5.7 ml/kg/min-1. Conclusion: Body mass of wings was lower than the goalkeepers and VO2 maximal and anaerobic threshold was higher than the wings of goalkeepers.

RELATIONSHIP BETWEEN MIDDLE-DISTANCE RUNNING PERFORMANCE AND POWERS ESTIMATED FRONT BLOOD LACTATE CONCENTRATION DURING INTERMITTENT RUNNING / 体力科学

This study was conducted to clarify the relationship between power estimated by blood lactate movement during intermittent running test (Maximal Anaerobic Running Test : MART), and velocity of middle distance running (V 800 m, V 1500 m) . The subjects were well-trained male middledistance runners (n=8) .<BR>MART consisted of a variable number of 20 seconds runs on a treadmill with a 100 seconds recovery period between runs. The runs were performed ona a 4° incline. After 40 second recovery, earlobe blood samples were taken and blood lactate concentrations were analyzed. The first run was performed at 250 m/min. Velocity of the treadmill was increased by 25 m/min for each consecutive run until volitional exhaustion.<BR>The power requirement associated with the absolute value of blood lactate (La) and relative value of peak blood lactate (PBLa) was determined from the La or %PBLa vs power curve by linear interpolation from the two consecutive La values which were above and below the desired value.<BR>Results were summarized as follows:<BR>(1) Maximal power (Pmax) for MART was correlated positively with V800m (r=0.880, P<0.01) and V1500m (r=0.948, p<0.001) .<BR>(2) Power estimated at 40% value of PBLa (P40%La) correlated positively with V 1500 m (r=0.903, P<0.01), and at 60% value of PBLa (P60%La) was correlated positively with V800m (r=0.835, P<0.01) and 1500m (r=0.936, p<0.001) .<BR>These results indicate that MART is a valid test for estimating middle distance running performance and P40%La, and P60%La are important indexes with 800-m and 1500-m running.

Effects of off-season training on anaerobic power and muscle thickness of varsity male rowers / 体力科学

The purpose of this study was to examine the effects of off-season training on the anaerobic power output and muscle thickness of male varsity rowers. 23 rowers participated in this study. Four all-out cycle ergometer work tests lasting 7 and 40 seconds were used to estimate anaerobic alactic power (AAP) and anaerobic lactic power (ALP) with leg (pedaling) and arm (cranking) exercises. AAP was computed as the highest power output during 7 seconds and ALP was obtained as the mean power output during 40 seconds. Muscle thickness was measured by B-mode ultrasonography at 11 sites on the body. There were significant differences between before and after off-season training in AAP (cranking : 8.4±1.00 vs 9.2±1.10W /kg, p<0.001, pedaling: 14.4± 1.10 vs 15.0±1.00 W/kg, p<0.001) and ALP (cranking : 5.2±0.42 vs 5.5±1.20W/kg, p<0.001, pedaling: 10.1±0.62 vs 9.5±2.10 W/kg, n, s.) . Muscle thickness increased significantly as a result of off-season training at sites on the biceps, triceps, pectoralis major, subscaplar and hamstrings. Similarly, there were significant differences in estimated muscle cross-sectional area (MCSA) on sites on the elbow flexor (20.6±2.6 vs 22.1±1.8cm<SUP>2</SUP>, p< 0.01), elbow extensor (25.3 ±4.8 vs 28.6±4.2cm<SUP>2</SUP>, p<0.001) and knee flexor (71.1±5.8 vs 74.3±5.2cm<SUP>2</SUP>, p<0.01) . The main training program in the off-season consisted of resistance training of the whole body. The high intensity training, used by male varsity rowers during off-season training, increased arm AAP, leg AAP, arm ALP and muscle thickness of the upper body ; but there was no difference in leg ALP and knee extensor muscle. It was suggested that improvements in leg ALP and knee extensor muscle are necessary to during the off-season training program of male varsity rowers.

Aerobic and anaerobic power and muscle thickness of varsity kayak paddlers / 体力科学

The purpose of this study was to clarify the characteristics of the ability of aerobic and anaerobic power output and the muscle thickness at each site of varsity kayak paddlers. Twenty-three male kayak paddlers who divided into skilled and unskilled group by their career participated in this study. Maximal oxygen uptake as a measure of aerobic power was determined with a progressive arm cranking exercise. Four all-out ergometer work tests lasting 7 and 40 seconds were used to estimate anaerobic alactic power and anaerobic lactic power with leg (pedaling) and arm (cranking) exercises. Anaerobic alactic power (AAP) was computed as the highest power output during 7 seconds and anaerobic lactic power (ALP) was obtained as the mean power output during 40 seconds. Muscle thickness were measured by B-mode ultrasonography at 11 sites on the body. Maximal oxygen uptake of skilled paddlers (3.501/min) was significantly higher than that of unskilled ones (2.701/min) . Similarly, there were significant differences between skilled and unskilled paddlers in AAP and ALP, especially as measured by the arm cranking exercise. The results showed that the career of arm-specific training induced the large specificity of aerobic and anaerobic power output with arm cranking mode. Muscle thickness of skilled paddlers were significantly larger than those of unskilled paddlers at sites on the biceps, abdomen, back muscles, quadriceps and hamstrings, and these strongly correlated with aerobic and anaerobic power output. It is suggested that for the improvement in power output it was necessary to train the muscles of trunk and thigh, and have a specific exercise mode.

The difference between effects of "power-up type" and "bulk-up type" strength training exercises. With special reference to muscle cross-sectional area, muscular strength, anaerobic power and anaerobic endurance / 体力科学

In this study, the difference between the effects of “power-up type” and “bulk-up type” strength training exercise was investigated by analyzing parameters such as structural and functional adaptations in the neuromuscular system. Eleven subjects were divided into power-up and bulk-up groups. The power-up group comprised five male subjects who performed 5 sets at 90% of one repetition maximum (1 RM) with a 3-min rest between sets (repetition method) . The bulk-up group comprised six male subjects who performed 9sets at 80-60-50%, 70-50-40%, and 60-50-40% of 1 RM with rest intervals between sets of either 30 s or 3 min (interval method) . Both groups performed isotonic knee extension exercise twice a week for 8 weeks. The power-up group showed a lower rate of improvement than the bulk-up group in terms of cross-sectional area (CSA) of the quadriceps femoris at levels 30%, 50% and 70% from the top of the femur, and also in average isokinetic strength (Isok. ave. ; 180 deg/s, 50 consecutive repetitions) . However, the power-up group showed a greater rate of improvement in 1 RM, maximal isometric strength (Isom. max), and maximal isokinetic strength (Isok. max ; 60, 180, 300 deg/s) . Furthermore, the rate of reduction in strength over 50 consecutive isokinetic repetitions decreased in the bulk-up group. On the other hand, the power-up group showed no significant changes in the above throughout the entire training program. These results indicate that the characteristics of the two types of training exercise are as follows : (1) power-up exercise is effective mainly for improving muscular strength and anaerobic power, and (2) bulk-up exercise is effective mainly for improving hypertrophy and anaerobic endurance. These findings support the idea that “power-up type” and “bulk-up type” strength training exercises should be applied appropriately according to the training aim.

Studies on muscle metabolism and cross-sectional area in the elite Japanese soccer players using NMR / 体力科学

We investigated the muscle energetics using <SUP>31</SUP>P nuclear magnetic resonance (<SUP>31</SUP>P NMR) spectroscopy, muscle cross-sectional area by magnetic resonance imaging (MRI), isokinetic strength, maximal anaerobic power and 40-sec maximal cycling test (40 seconds power) in All Japan soccer players (JPN: n=6), Olympic and Youth representatives (OL: n=6), and Japan Soccer League players (JSL: n=5) . There was no significant difference in muscle energy metabolism measured by <SUP>31</SUP>P NMR between the JPN and the OL or JSL players at rest, during exercise, or in the recovery period. The total muscle cross-sectional area was significantly larger in the JPN players than in the OL players at the upper (70%) and the middle (50%) parts of the thigh (p<0.05) and than in the JSL players in the upper (p<0.01), middle (p< 0.05), and lower (30%) parts (p<0.01) . The isokinetic strength in left leg extension at 180 deg/sec was significantly greater in the JPN players than in the OL players (p<0.05) . Muscle strength was also greater in extension of both legs at 450 deg/sec (left p<0.05, right p<0.01) in the JPN players than in the JSL players. The maximum anaerobic power was significantly greater in the JPN players than in the OL players (p<0.05) and the JSL players (p<0.05), and the anaerobic power per kilogram of body weight was significantly higher in the JPN players than in the JSL players (p<0.01) . There was no significant difference in the 40 seconds power among the three groups. These results suggest that the JPN players have greater muscle power than the OL or JSL players because of the differences in the muscle mass.

The Effect of "Living High and Training Low" with a Normobaric Hypoxic Tabernacle on Exercise Performance of Rowers / 中国运动医学杂志

This study was to investigate the influnce of 4 weeks of living high-training low on exercise performance of rowers. Twenty rowers were divided into two groups: ten subjects spent 8-10h per night in a tabernacle simulated at an altitude of 2500m in normobaric hypoxia; 10 control subjects slept at near sea level. During the 4-week periods, all rowers were trained at the same relative or at the same intensity of work in normoxia state. The red cell volume (RCV) , haemoglobin mass (Hb) and hematocrit (HCT) were measured before test, 15th and 30th day of study,and measurements were done on a rowing ergometer at sea-level, which included an ergometer test at 4 mmol/L lactate anaerobic threshold and performance in exercise tasks of 2km, 5km, and a Wingate Anaerobic Test before test and 30th day of study. The results showed that adaptation to simulated moderate altitude can stimulate red cell production sufficiently: increase in red cell volume (RCV) , haemoglobin mass (Hb) and hematocrit (Hct). And there were significant increases in all important parameters at 4 mmol/L lactate anaerobic threshold as well as performance of 5km, while the performance of 2km showed no significant improvement, the mean values of both mean power per kilogram body weight and peak power per kilogram body weight were not increased significantly. In the control group, there were no significant changes in the all abovementioned parameters. The results of this study indicate that living high-training low can improve the aerobic energy-supply systems. We conclude that 4-week of living high and training low can improve sea level endurance performance in rowers.