The effects of high-intensity intermittent training on metabolic or circulatory parameters and exercise time during 30s lasting exhaustive exercise / 体力科学

Present study aimed to examine the effects of high-intensity intermittent training on metabolic or circulatory parameters and exercise time during 30s-lasting exhaustive exercise. Six healthy males (22 ± 1yrs) had an intermittent training four days a week for four weeks. The intermittent training consisted of 8 or more sets of 20s exercise bout at an intensity of 170%VO2 max separated by 10-s recovery. Before and after training period, VO2 max and maximal accumulated O2 deficit (MAOD) were determined as indices of metabolic capacity. During 30s-lasting exhaustive exercise, VO2, O2 deficit, and circulatory parameters, such as heart rate, stroke volume, and cardiac output, were also determined every 10s. After the training, VO2 max and MAOD were significantly increased. During 30s-lasting exhaustive exercise, exercise time, stroke volume, and cardiac output were also significantly enhanced. However, no significant differences were observed in VO2 and O2 deficit every 10s during 30s-lasting exhaustive exercise. Therefore, these findings suggest that high-intensity intermittent training enhances exercise time during 30s-lasting exhaustive exercise and that the improvement of exercise performance is closely related to an increase in anaerobic capacity.

Efectos de los métodos de entrenamiento discontinuo en atletas de combate colombianos / Effects of discontinuous training methods in Colombian combat athletes / Efeitos dos métodos de treinamento descontínuo nos atletas de combate colombianos

Objective: To determine the effectiveness of the discontinuous training of the VO2Máx, in a competitive period, in combat athletes who live and train in Medellín-Colombia, with national or international sports level. Method: A convenience sample of 42 subjects was selected: 15 women and 27 men, 21 of them judo athletes, 9 fenders, 6 taekwondo athletes, and 6 fighters, from the selections of Antioquia in the Absolute Category, with age = 21.26 ± 3,98 years, size: 1.69 ± 0.09 m, weight = 65.70 ± 12.05 k, and sports experience of 8.54 ± 4.27 years. They were randomly distributed in two experimental groups and one control group. Experimental groups trained endurance for 4 weeks, with 4 stimuli per week, before the National Games, the maximum sports competition in Colombia. One experimental group trained with the interval method and the other with the intermittent method. The control group did not perform a specific endurance training, maintaining the strength training and the technical-tactical components, similarly to the subjects integrating the experimental groups. Results: Significant differences between the pre-test and the post-test for the intermittent group (p < 0.05), and not for the interval or the control groups, were found. Conclusions: Endurance training, based on the intermittent method, produced significant differences in VO2Máx in combat athletes from Antioquia, during the final phase of its preparation. Likewise, it was found that the number of workouts carried out during a concentrated block of specific endurance training significantly influenced the changes that occurred in VO2Máx.

Objetivo: determinar la efectividad del entrenamiento discontinuo en el VO2Máx., en período competitivo, en atletas de combate que viven y entrenan en Medellín-Colombia, con nivel deportivo nacional o internacional. Método: se seleccionó, a conveniencia, una muestra de 42 sujetos: 15 mujeres y 27 hombres, de ellos 21 judokas, 9 esgrimistas, 6 taekwondokas y 6 luchadores, de las Selecciones Antioqueñas de la Categoría Absoluta, con edad= 21,26±3,98 años, talla: 1.69±0.09 m, peso= 65.70± 12.05 k. y experiencia deportiva de 8.54±4.27 años. Fueron distribuidos aleatoriamente en dos grupos experimentales y un grupo control. Los grupos experimentales entrenaron la resistencia durante 4 semanas, con 4 estímulos por semana, antes de ir a los Juegos Nacionales, máxima competencia deportiva en Colombia. Un grupo experimental entrenó con el método interválico y el otro con el método intermitente. El grupo control no realizó un entrenamiento específico de la resistencia, manteniendo el entrenamiento de fuerza y de las componentes técnico-tácticas en forma semejante a la de los sujetos que integraron los grupos experimentales. Resultados: se hallaron diferencias significativas entre el pre-test y el pos-test para el grupo intermitente (p<0,05), no así para el interválico ni el control. Conclusiones: el entrenamiento de la resistencia basado en el método intermitente, produjo diferencias significativas en el VO2Máx. en atletas Antioqueños de Combate, durante la fase final de su preparación. Igualmente, se encontró que el número de entrenamientos realizados durante un bloque concentrado de entrenamiento de la resistencia específica influyó de manera significativa en los cambios que se produjeron en el VO2Máx.

Objetivo: determinar a efetividade do treinamento descontínuo e verificar se é possível melhorar o VO2Máx no período competitivo de atletas de combate que vivem e treinam em Medellín- Colômbia, com nível desportivo nacional ou internacional. Método: Selecionou-se uma amostra a conveniência de 42 sujeitos 15 mulheres e 27 homens , deles 21 judocas, 9 esgrimistas , 6 lutadores e 6 taekwondokas das Seleções antioqueñas da categoria absoluta, com idades = 21,26 ± 3, 98 anos; tamanho: 1,69 ± 0,09 m; peso = 65,70 ± 12,05 k. e 8,54 ± 4,27 anos de experiência esportiva. Eles foram distribuídos aleatoriamente em três grupos: dois grupos experimentais e um grupo controle. Os grupos experimentais treinaram resistência por 4 semanas com 4 estímulos por semana antes de irem aos Jogos Nacionais para a competição máxima de esportes na Colômbia. Um dos grupos experimentais baseou seu treinamento no método intervalado e o outro no método intermitente. Por sua vez, o grupo controle não realizou nenhum treinamento de resistência específico, mantendo o treinamento de força e os componentes técnico-táticos de forma semelhante aos sujeitos que integraram os grupos experimentais. Resultados: Diferenças significativas foram encontradas entre o pré-teste e o pós-teste para o grupo intermitente (p <0,05), mas não para o grupo intevalado nem para o grupo controle. Conclusão: o treinamento de resistência com base no método intermitente produz diferenças significativas no VO2Máx em atletas combate antioqueños durante a fase final de sua preparação. Também descobriram que o número de treinos realizados durante um bloco concentrado de treino da resistência específica influenciou significativamente as mudanças que ocorrem no VO2Máx.

Effects of High-Intensity Intermittent Training and FATmax Intensity Continuous Training on Body Composition of Female College Students / 中国运动医学杂志

Objective To investigate the effect of 10-week high-intensity intermittent training(HIIT) and maximum fat oxidation (FATmax)intensity training on body composition of female college students,and explore the difference between the 2 training types.Methods Thirty female college students were divided into an HIIT,an FATmax intensity training(FATmax)and a control(CON)group,each of 10.The HIIT and FATmax groups completed a 10-week high-intensity intermittent training and FATmax intensity continuous training with 90％ VO2 max and FATmax intensity respectively,while the CON group maintained the daily habitual behavior.The body weight,waist circumference,hip circumference and skinfold thickness of the triceps,midaxillary,chest,subscapular,abdomen,suprailiac and thigh were measured before and after the intervention.The body composition was evaluated using the Jackson/ Pollock seven-point method.Results The body max index(BMI),waist circumference,hip circumference and waist-hip ratio(WHR)decreased significantly in HIIT and FATmax groups after the 10-week training(P＜0.05),whereas the waist circumference and WHR of the CON group increased(P＜0.05).The decline rate of BMI,waist circumference,hip circumference and WHR of FATmax and HIIT groups were higher than that of the CON(P＜0.01),but there was no difference between the FATmax and HIIT groups.We further noticed no change in the bodyweight and body composition of the CON group,while a significant decrease in the bodyweight,fat percentage and fat mass (P＜0.001),but a significant increase(P＜0.01)in the lean body mass was observed in the FATmax and HIIT groups after the training.Ten weeks of HIIT significantly decreased the fat percentage and fat mass of the exercise groups compared with CON group(P＜0.05),and the rate of fat loss and lean body mass gain of the HIIT group was significantly higher than the FATmax group(P＜0.05).Moreover,the exercise intervention significantly decreased the skinfold thickness of the FATmax and HIIT groups(P＜0.001),but no changes in the CON group.Before the training,there was no significant difference in skinfold thickness among the three groups.However,after the training,the skinfold thickness of the chest,midaxillary,abdomen,suprailiac and thigh of the HIIT group was lower than CON(P＜0.05),and skinfold thickness of abdomen in HIIT group was lower than FATmax group(P＜0.05).Moreover,the decline rate of the skinfold thickness in the midaxillary,suprailiac,subscapular and thigh of the HIIT group was higher than the FATmax group(P＜0.05).Conclusion Both HITT and FATmax intensity continuous training of ten weeks sgnificantly improve the bodyweight,waist circumference,hip circumference and WHR without significant differences.Moreover,they both are effective in bettering the body composition and subcutaneous fat of female college students,with HITT superior to the FATmax intensity continuous training.

Effects of high-intensity intermittent training on carnitine palmitoyl transferase activity in the gastrocnemius muscle of rats

We examined the capacity of high-intensity intermittent training (HI-IT) to facilitate the delivery of lipids to enzymes responsible for oxidation, a task performed by the carnitine palmitoyl transferase (CPT) system in the rat gastrocnemius muscle. Male adult Wistar rats (160-250 g) were randomly distributed into 3 groups: sedentary (Sed, N = 5), HI-IT (N = 10), and moderate-intensity continuous training (MI-CT, N = 10). The trained groups were exercised for 8 weeks with a 10% (HI-IT) and a 5% (MI-CT) overload. The HI-IT group presented 11.8% decreased weight gain compared to the Sed group. The maximal activities of CPT-I, CPT-II, and citrate synthase were all increased in the HI-IT group compared to the Sed group (P < 0.01), as also was gene expression, measured by RT-PCR, of fatty acid binding protein (FABP; P < 0.01) and lipoprotein lipase (LPL; P < 0.05). Lactate dehydrogenase also presented a higher maximal activity (nmol·min-1·mg protein-1) in HI-IT (around 83%). We suggest that 8 weeks of HI-IT enhance mitochondrial lipid transport capacity thus facilitating the oxidation process in the gastrocnemius muscle. This adaptation may also be associated with the decrease in weight gain observed in the animals and was concomitant to a higher gene expression of both FABP and LPL in HI-IT, suggesting that intermittent exercise is a "time-efficient" strategy inducing metabolic adaptation.

Fiber type composition in semitendinous muscle of Wistar rats and effects of intermittent training on its hypertrophy / Composición de los tipos de fibras del músculo semitendinoso de ratas Wistar y los efectos del entrenamiento intermitente en su hipertrofia

Skeletal muscles respond to several stimuli changing their phenotype. Muscular fibers adaptation capability is related to the presence of several myosin heavy chains (MHC). These express four types of pure fibers: I, IIA, IID and IIB containing MHCI, IIa, IId and IIb, respectively. Among pure fibers, there are hybrid fibers, which can express two or more types of myosins. In this study, types of fibers constituting male Wistar rats semitendinous and their myosin heavy chains, as well as influence of intermittent training on hypertrophy of these fibers have been checked through MATPase histochemical technique and electrophoretic proteins separation. All types of pure and hybrid muscular fiber have been found, however the fibers of the types IIA, IID and IIB were predominant, featuring muscle as a fast-contracting one. Training has promoted muscular fibers transition with a significant increase of fibers of IC, IIAD and IIDB type. A cross-section increase of fibers of IIDB and IIB type has also been noticed. In summary, semitendinous muscle is essentially constituted by fast-contracting fibers and training could promote transition and hypertrophy of these fast fibers.

Los músculos esqueléticos responden a diversos estímulos cambiando su fenotipo. La capacidad de adaptación de las fibras musculares está relacionada con la presencia de diversas miosinas de cadena pesada (MHC). Estas miosinas expresan cuatro tipos de fibras puras: I, IIA, IID, IIB, que contienen MHCI IIa IId IIb, respectivamente. Entre las fibras puras hay fibras híbridas, las cuales pueden expresar dos o más tipos de miosinas. En este trabajo, se observaron los tipos de fibras y las cadenas pesadas de miosinas del músculo semitendinoso en ratas Wistar macho, así como también, la influencia del entrenamiento intermitente en la hipertrofia de aquellas fibras, a través de la técnica histoquímica de mATPasa y separación eletroforética de proteínas. Todos los tipos de fibras musculares puras e híbridas fueron encontradas, siendo las fibras de tipo IIA IID y IIB predominantes, por ser un músculo de contracción rápida. El entrenamiento promovió la transición de las fibras musculares con un aumento significativo de las fibras del tipo IC, IIAD y IIDB. En una sección transversal, un incremento de fibras del tipo IIDB y IIB también fue reportada. En resumen, el músculo semitendinoso está compuesto esencialmente por fibras de contracción rápida y el entrenamiento puede promover la transición e hipertrofia de las fibras musculares rápidas.

Effect of high intensity intermittent training and resistance training on the maximal oxygen defieit and VO2max / 体力科学

This study examined the effects of (1) an intermittent training using a mechanically braked cycle ergometer and (2) resistance training using free weight on the maximal oxygen deficit and VO<SUB>2</SUB>max. For the first 6 weeks, six subjects trained using an intermittent training protocol five days per week. The exhaustive intermittent training consisted of seven to eight sets of 20 s exercise at anintensity of about 170% of VO<SUB>2</SUB>max with a 10 s rest between each bout. After the training, the maximal oxygen deficit increased significantly from 64.3±5.0 ml⋅kg<SUP>-1</SUP> to 75.1±5.7 ml⋅kg<SUP>-1</SUP> (p<0.01), while VO<SUB>2</SUB>max increased from 52.0±2.7 ml⋅kg<SUP>-1</SUP>⋅min<SUP>-1</SUP> to 57.6±2.9 ml⋅kg<SUP>-1</SUP>⋅min<SUP>-1</SUP> (p<0.05) . For the following 6 weeks, the subjects used the same intermittent training for 3 days per week and a resistance training for the other 3 days per week. The resistance training consisted of (1) 4 sets of 12 bouts of squat and leg curl exercise at 12 repetition maximum (RM) . (2) 2 sets of maximal bouts of the same exercise with a load of 90%, 80%, and 70% of 1 RM. After the training period, the maximal oxygen deficit increased further to the value of 86.8±5.9 ml⋅kg<SUP>-1</SUP>which was significantly higher than the value attained at the end of the intermittent training. On the other hand, VO<SUB>2</SUB>max did not increase significantly from the value observed at the end of the 6 weeks of intermittent training. Body weight was not significantly changed throughout the 12-week training period. Maximal circumference of the thigh did not changed during the first 6-week of the intermittent training period (pre-training: 57.1±1.2 cm, after 6-week training: 57.3±1.1 cm), while it increased significantly after the last 6-week combined training (59.0±0.8 cm, p<0.05) . In conclusion, this study showed that (1) high intensity intermittent training improves both the anaerobic and aerobic energy supplying systems, (2) additional resistance training with the intermittent training further increases the anaerobic energy supplying system, probably through increased muscle mass.