This study aims to analyze the effects of an 8-week strength training program combining different exercise intensities and blood flow restriction (BFR) conditions on safety, tolerability, muscle adaptations, and physical performance variables. Three training modalities will be compared: 1) high-intensity exercise with BFR therapy; 2) low-intensity exercise with BFR therapy; and 3) high-intensity exercise without BFR therapy. All groups will perform the same exercise modality, differing only in intensity and the application of BFR.

Participants will be randomly assigned to one of the three groups and will undergo a 8-week intervention. The variables of interest will be assessed in each group for subsequent analysis and comparison.

Inclusion Criteria:

• Healthy, untrained adults
• Age between 18 and 65

Exclusion Criteria:

• Current participation in an upper limb strength training program
• Presence of comorbidities that increase cardiovascular risk (uncontrolled ischemic heart disease, uncontrolled hypertension, diabetes, etc.)
• Patients with more than one thromboembolism risk factor (obesity, history of thrombosis, prolonged immobilization, recent surgery, use of contraceptives, etc.)
• Current diagnosis of any pathology affecting the cervical spine, shoulder, and/or thoracic spine
• History of surgery in the last year
• Use of ergogenic aids or medications that affect muscle metabolism (anabolic steroids, testosterone, creatine, protein supplements, corticosteroids, chronic use of nonsteroidal anti-inflammatory drugs, etc.)

The data that support the findings of this study will be available from the corresponding author upon reasonable request.