Blood flow restriction (BFR) is a widely studied technique that combines low-intensity exercise with vascular occlusion, resulting in muscular benefits. However, its application is challenging due to methodological variations and equipment costs. Tissue Flossing (TF) appears as an affordable alternative, but lacks solid scientific evidence.

Objectives: to evaluate the intra- and inter-rater reliability of the occlusion pressure generated by TF, investigate the reproducibility of TF application on different days and compare TF with traditional RFS in terms of muscle gains.

Methods: the study is divided into two stages: First stage, randomized controlled crossover clinical trial, 80 healthy individuals aged 18 to 30 years old evaluated to determine the reliability of the TF. Participants will follow one of two types of randomization, with exclusions based on health criteria. Assessments include anthropometric characteristics, determination of occlusion pressure (POT), identification of 40% and 80% of POT, flow data and arterial diameter after TF application. Statistical analysis will use the intraclass correlation index (ICC) and specific models for intra- and inter-rater analyses. Second stage, randomized controlled clinical trial with parallel groups, 34 participants will be evaluated over fifteen weeks. The initial procedures involve anthropometric assessments, POT determination, myotonometry, ultrasound, perceptual scale and 1RM test, applied to both upper limbs. Participants will perform a upper limb training protocol using RFS or TF, following myotonometric and perceptual assessments. After training, final assessments will measure the same parameters initially assessed. Statistical analysis will use normality tests, Generalized Mixed Models and effect size analysis in SPSS software, with a significance level of p<0.05. Expected results: This study is expected to provide information on the reliability and reproducibility of TF in generating occlusion pressure. Furthermore, the investigatorsF seek to validate TF by comparing it with traditional RFS in terms of muscle gains. If effective, TF could become an affordable option to promote muscle gains, in different application scenarios.

Participants will be duly informed about the procedures and objectives of this study, and after agreeing, they will sign an informed consent form, effectively becoming part of it. In the consent form, participants will be asked if they agree to the use of their data if they choose to withdraw from the study. Participants will also be asked for permission for the research team to share relevant data with people at universities participating in the research or regulatory authorities, where relevant. The study were approved to the Research Ethics Committee of FCT/UNESP, Presidente Prudente, SP, Brazil.

Inclusion Criteria:

• Individuals who present one or more of the following characteristics will not be included:
• 1 presence of any health condition that contraindicates or prevents exercise;
• 2 diabetes and diagnosed high blood pressure;
• 3 inflammatory, psychiatric, cardiovascular and/or respiratory rheumatological disease; - -4 being dependent on alcohol, consuming drugs and/or being a smoker;
• 5 history of knee surgery (e.g., meniscal repair and ligament reconstruction) or recent upper limb musculoskeletal injury that may impair performance during tests or interventions (e.g., muscle injury, tendinopathy, patellofemoral pain and/or back pain column in the last six months);
• 6 use of ergogenic supplements to improve physical performance and/or muscle mass and/or vasoactive medications;
• 7 having one or more risk factors predisposing to thromboembolism

Exclusion Criteria:

• Participants will be excluded from the study if they:
• 1 have a health problem that does not allow them to continue;
• 2 wish to leave the study;
• 3 not sign the consent form