Effects of strength training with Vascular Occlusion associated with Electrical Stimulation

INTERVENTION: E02.760.169.063.500.387.125 Participants will be randomized into two groups of 30 individuals: Blood Flow Restriction Group (BFRG) and Blood Flow Restriction Associated with Electrical Stimulation Group (BFRESG), totaling 60 participants, through randomization in 10 blocks of 6, through raffle held on a specialized site. The evaluator and the statistician will not know which group each individual was allocated to. The BFRG individuals will undergo the application of the blood flow restriction technique, with the pressure cuff positioned in the proximal third of the thigh (inguinal crease region) in the limb that will be determined during randomization. A pressure corresponding to 50% of the total occlusion pressure will be applied so that an equivalent and individualized restriction of the participants occurs. This pressure will be adjusted by 5% each week of the protocol until reaching 80% of the total restriction pressure. Four series of 30, 15, 15, 15 repetitions respectively of knee extension will be performed in the extension chair with 30% of 1 maximum repetition and the pressure cuff will remain inflated throughout the exercise and rest between series, which will be standardized in one minute. The BFRESG will receive the same restriction parameters as the BFRG associated with electrical stimulation of the quadriceps muscle, using bipolar electrodes connected to a neuromuscular electrical stimulator (Neurodyn II Ibramed®). The stimulation current will be in the form of an asymmetric biphasic wave with a rising and falling ramp of 2s and 1s, respectively, frequency of 50Hz and pulse duration of 400us. The contraction time will be 5s, with a rest of 10s (ratio 1:2). The intensity will have the participant s motor threshold as a reference, as well as the visible quadriceps muscle contraction CONDITION: G11.427.578 Muscle development PRIMARY OUTCOME: Muscle thickness before and after the interventions will be evaluated by means of ultrasonography through the images that will be obtained through the GE Voluson I system (GE Healthcare, Zipf, Austria) in two‐dimensional mode (B) with linear transducer. All muscle thickness measurements will be performed by a previously trained investigator. For the evaluation, participants will be positioned in dorsal decubitus to avoid hip rotation and both limbs, dominant and non‐dominant, will be evaluated. To obtain the image, conductive gel will be used for better reproduction of the images and the measurement of the distance between the anterior superior iliac spine and the upper border of the patella will be standardized by means of a vertical line. Then, the rectus femoris and the vastus intermedius will be measured from 50% of this distance. INCLUSION CRITERIA: Will be included in the study participants of both sexes; aged between 18 and 45 years; physically active SECONDARY OUTCOME: Muscle strength will be assessed using an isokinetic dynamometer. The participant will be seated, with hip and knee flexion of 90º and accommodated with inelastic bands to avoid compensations during the evaluation. The dynamometer axis will be positioned towards the lateral femoral condyle. The resistance pad will be fixed at the level of 3cm away from the malleolus ; medial. Isokinetic measurements will be performed under a concentric/concentric protocol to assess muscle performance at two angular velocities: 60º/s and 300º/s. Five movement practices will be performed without maximum strength for the volunteer to familiarize himself with the equipment; then, a verbal stimulus will be given so that maximum strength is performed during the test of five repetitions (60º/s), followed by fifteen repetitions of the second protocol (300º/s). There will be a 40 second rest interval between tests. The evaluation will be carried out bilaterally, with the dominant limb being evaluated first or the one that does not present any recent injury. The collected variables will be the peak torque, time of peak torque and power of the knee flexors