RESUMEN
BACKGROUND: Low-intensity resistance exercises with blood flow restriction have been shown is effective to increase muscular strength and hypertrophy. However, the effects of combined training: one-week occlusion training with various exercise intensities by using less occlusion pressure on muscle strength improvement, fatigability and their work capacity are not clear. METHODS: Participants (N.=24) were middle-distance runners with 4-6 years of training experience. A control group without blood flow restriction (N.=12, age 23±1 years) and an experimental group with blood flow restriction (N.=12, age 22±1 years). In this study, the calf muscles were impacted by the training with occlusion 120 mmHg. We used intensive one-week daily training, whereby exercise intensity was gradually increased daily from 20% to 80% of maximal voluntary contraction (MVC) and then decreased to 60% by the end of the week. RESULTS: MVC of foot flexion muscles after the one-week occlusion training in the experimental group and control group increased (P<0.05) by 5.6±1.3% and 5.3±1.2%, respectively. Meanwhile in experimental group work capacity improved only 2.4±3.5% (P>0.05) and in control group it significantly decreased 11.8±2.5% (P<0.05). StO2 decreased during exercise test from the baseline 100% to 45.2±4.3% before occlusion training and to 34.6±6.2% after the week of occlusion training (P<0.05). CONCLUSIONS: Intensive one-week training with occlusion with varying intensity improves resistance to fatigue and recovery after training. This kind of training improves oxygen consumption while exercising.
Asunto(s)
Fatiga Muscular , Músculo Esquelético/fisiología , Consumo de Oxígeno/fisiología , Entrenamiento de Fuerza/métodos , Adulto , Estudios de Casos y Controles , Prueba de Esfuerzo/métodos , Femenino , Hemodinámica , Humanos , Masculino , Fuerza Muscular/fisiología , Músculo Esquelético/irrigación sanguínea , Flujo Sanguíneo Regional , Adulto JovenRESUMEN
PURPOSE: This study aimed to examine the effect of acute blood flow restriction during the late recovery phase between two resistance exercise bouts on muscular endurance and oxygenation. METHODS: Amateur male middle- and long-distance runners performed two bouts of one-leg dynamic plantar flexion exercise to failure with the load equivalent to 75% of maximum. Subjects were randomly assigned into two experimental groups with thigh occlusion pressure between bouts at either 120 or 200 mmHg with 20 min of passive rest in between, and two control groups without any blood flow restriction separated by either 5 or 20 min of rest. Blood flow restriction in the experimental groups was implemented during the last 15 min of recovery. Calf arterial blood flow and muscle oxygenation were measured by venous occlusion plethysmography and near-infrared spectroscopy, respectively. RESULTS: Decrease of muscular oxygenation and blood flow during recovery between exercise bouts depended on the applied occlusion pressure. When compared with bout 1, work capacity in the experimental groups during bout 2 was reduced by 9.3 ± 2.2% with 120 mmHg and by 10.5 ± 3.1% (p < 0.05) with 200 mmHg occlusion pressure. In the control groups, work capacity was restored after 20 min (- 3.9 ± 3.2%, p > 0.05) but not after 5-min recovery (- 20.0 ± 1.8%, p < 0.05). CONCLUSIONS: Blood flow restriction late in recovery after a heavy resistance exercise bout decreased muscle oxygenation and work capacity during the subsequent heavy resistance exercise bout.
Asunto(s)
Músculo Esquelético/fisiología , Recuperación de la Función , Reperfusión/métodos , Entrenamiento de Fuerza/efectos adversos , Arterias/fisiología , Humanos , Masculino , Fatiga Muscular , Músculo Esquelético/irrigación sanguínea , Consumo de Oxígeno , Flujo Sanguíneo Regional , Reperfusión/efectos adversos , Muslo/irrigación sanguínea , Muslo/fisiología , Adulto JovenRESUMEN
[Purpose] Occlusion training with low-intensity resistance exercises and blood flow restriction increases muscle cross-sectional area and strength. This form of training is used in rehabilitation; therefore, the aim of this study was to examine the effect of one occlusion training session on the cardiovascular response to bouts of exercise. [Subjects and Methods] Two groups took part: a control group without blood flow restriction and an experimental group with blood flow restriction. A single training session was used with the exercise intensity set at 40% of the one repetition maximum. Maximum voluntary contraction, arterial blood pressure, and electrocardiogram measurements were performed. [Results] Heart rate was slightly higher in the control group. The performed training had no effect on diastolic blood pressure in either group, however, a tendency for a small systolic blood pressure increase was observed during the session in the experimental group. JT interval changes did not reveal significant differences between groups. There were no significant changes in ST-segment depression during the exercise or at rest. A lower tendency for JT/RR increases was observed during the repeated exercise tasks with partial blood flow restriction. [Conclusion] Low intensity exercises carried out with a partial blood flow restriction do not result in significant overload of cardiac function.