Effect of Blood Flow Restriction on Recovery After Maximal Resistance Exercise

Muscle power will be assessed through the Squat Jump test using a contact platform (Multisprint). Participants will begin in a 90° knee flexion position (verified with a goniometer), with hands on hips, and will perform a vertical jump without countermovement. Variables to be analyzed will include jump height, modified reactive strength index, jump power, and take-off moment.

Muscle function will be assessed through the single leg hop functional test sing a measuring tape in centimeters. The participant will be positioned standing on a flat surface, barefoot, and with their hands on their waist. They will be asked to perform a horizontal jump with the greatest possible reach using only one lower limb (test performed unilaterally). The contralateral limb will remain flexed without touching the ground during the execution. After the jump, the participant must maintain balance for at least two seconds without losing stability or moving the landing foot. The jump distance will be measured in centimeters from the toe of the supporting foot (before the jump) to the heel at the moment of landing, using a measuring tape.

The isometric peak torque of the quadriceps and hamstring will be measured using a digital handheld dynamometer (DD-300, Instrutherm). For the quadriceps strength assessment, the participant will be seated in a chair with their knee bent at 90° and instructed to push maximally against the dynamometer. To measure hamstring strength, the participant will be positioned in a prone position with their knee flexed at 90º and will be instructed to push maximally against the dynamometer. Three attempts will be performed with a 1-minute rest interval. The highest value will be used for analysis.

Muscle soreness will be assessed using a Numeric Pain Rating Scale (0-10). Pain threshold will be measured with a pressure algometer (FPX 50/220; Wagner) at four sites: biceps femoris and rectus femoris. Measurements will be recorded in kgf and will not exceed 2.55 kgf.

Perceived exertion, recovery, and discomfort will be measured using the Borg CR-10 scale (0-10). Participants will rate: (1) exertion as whole-body effort, (2) discomfort as muscular sensations in the lower limbs, and (3) recovery as general physical and psychological recovery. Values will be individually recorded at each time point.

Muscle tone, stiffness, and elasticity will be measured using the MyotonPRO device. The probe will be positioned perpendicularly over the following sites: biceps femoris and rectus femoris. The device will apply a 0.18 N pre-load and a 0.40 N impulse to induce tissue oscillation for measurement.

Bioimpedance will be measured using a tetrapolar device (BIA Analyzer, 50 kHz, 800 µA). Electrodes will be positioned on the biceps femoris and rectus femoris. Analyzed variables will include resistance (R), reactance (Xc), phase angle (PhA), and tolerance ellipse, via Bioscan software.

To determine the AOP, the Doppler equipment transducer will be used, which will be positioned over the posterior tibial artery to capture the auscultatory pulse. A blood pressure cuff will be fixed to the participant's thigh close to the region of the inguinal fold of the dominant limb, and then with the inflatable region of the cuff on the medial portion of the thigh covering the femoral artery, it will be progressively inflated, waiting 15 seconds every 30 mmHg until the point at which the auscultatory pulse of the tibial artery is interrupted.