Effects of Warm-up Intensity and Blood Flow Restriction

Introduction: warming up has the function of preparing the body structures for a given task to be performed during sports, increasing body and muscle temperature, focusing on improving performance. Therefore, the use of the blood flow restriction technique (BFR) can be seen as a promising alternative for promoting greater mechanical and muscular stress, thus providing a more efficient warm-up and optimizing performance. Objectives: to analyze the effects of RFS used during low-intensity warm-up compared with low-intensity and high-intensity warm-up without RFS on performance (jump test and 30-meter sprint test) and skin surface temperature. In addition to analyzing and comparing, after the warm-up protocols with and without RFS, the acute responses on perceptual outcomes (perception of pain, change in sensitivity, subjective perception of exertion and perception of discomfort in relation to RFS) and muscle outcomes (tonus , muscle stiffness and elasticity). Methods: a randomized controlled clinical trial will be carried out, with 33 amateur soccer players aged between 18 and 35 years who will be randomly divided into three groups: low-intensity warm-up without RFS (30% VO2max), high-intensity warm-up without RFS ( 80% VO2max) and low-intensity warm-up associated with BFR (80% of total occlusion pressure) \[30% VO2max-BFR\]. All groups will carry out the heating protocol and the outcomes will be evaluated at baseline and immediately after the end of the heating, as well as 10 and 20 minutes after its completion, namely: skin surface temperature through thermography; tone, stiffness and muscle elasticity by myotometry, subjective perception of pain (VAS); pain threshold through the pressure algometer; subjective perception of exertion (BORG scale); perception of discomfort in relation to RFS (LIKERT-CR-10 scale); 30-meter sprints measured through photocells and vertical jump, measured through the force platform. Descriptive statistics will be used and comparisons will