Effects of Back Squat Exercise with or Without Blood Flow Restriction in Healthy Adolescent Basketball Athletes

The goal of this clinical trial is to assess the effectiveness of Blood Flow Restriction (BFR) training compared to traditional high-intensity training in adolescent basketball players aged 16-18. The main questions it aims to answer are:

Does BFR training improve muscle strength more effectively than traditional high-intensity training? Does BFR training enhance jump height and ground reaction force (GRF) while reducing mechanical load? Researchers will compare BFR training to traditional high-intensity training to see if BFR training offers greater improvements in muscle strength, jump height, and GRF while potentially reducing knee joint stress.

Participants will:

Be randomly assigned to either the BFR training group or the high-intensity training group.

Undergo performance evaluations, including measurements of muscle strength, jump height, and GRF at three time points throughout the study.

Follow a training protocol specific to their assigned group

Detailed Description:

This randomized controlled study aims to evaluate the effectiveness of Blood Flow Restriction (BFR) training compared to traditional high-intensity training in adolescent basketball players, focusing on performance enhancement and safety. The study was approved by the Committee Research Ethics of Saint Joseph University of Beirut (Code: 2023-325) on December 7, 2023.

Study Setting and Participants: The research was conducted within two sports academies in Lebanon, Mont La Salle and Rebound academies. A total of 50 adolescent basketball players, aged 16-18 years, participated. Inclusion criteria required regular training (at least three sessions per week) and competitive basketball experience within the last six months. Exclusion criteria included history or presence of cardiovascular, pulmonary, or metabolic conditions, vascular disorders, coagulation disorders, or ongoing anticoagulant therapy. Before starting the study, participants completed a recruitment questionnaire to gather demographic data and assess eligibility for BFR training.

Study Design and Randomization: Participants were randomly assigned into two groups:

Group 1 (BFR Training Group): Engaged in low-intensity resistance training (20-30% of 1RM) with BFR using pressure cuffs on the lower limbs.

Group 2 (High-Intensity Training Group): Engaged in traditional high-intensity resistance training (65-80% of 1RM) without BFR.

Both groups completed 12 sessions over six weeks, with a 48-hour interval between sessions. The study's structured approach allows for a comparison of the training modalities' effects on muscle strength, jump height, and ground reaction force (GRF).

Evaluation Protocol: Participants underwent baseline assessments before starting the exercise regimen. These assessments included occlusion pressure, 1-repetition maximum (1RM) testing, muscle strength, jump height, and GRF.

Occlusion Pressure Measurement: Measured using the VALD-performance system (Version 3 of the Airbands model, Australia) with athletes seated and cuffs placed proximally on the thigh (25% of the femur length).

1RM Testing: Participants performed warm-up sets before progressively increasing load until reaching the maximum weight they could lift with proper form.

Muscle Strength: Assessed using a digital dynamometer (KINVENT, K-PULL, France) for both quadriceps and hamstring muscles.

Jump Height and GRF: Evaluated using a force platform (KINVENT, France) during counter-movement jumps (CMJs).

Evaluations were conducted at three time points: baseline (M1), mid-intervention at three weeks (M2), and post-intervention at six weeks (M3). Each measurement was performed three times to ensure inter-rater reliability, with four physiotherapists maintaining consistency by evaluating the same athletes throughout the study.

Intervention Protocols:

Group 1 (BFR Training Group): Performed four sets of back squats at 20% of 1RM during weeks 1-3, increasing to 25% at week 3, and 30% during weeks 5-6.

Group 2 (High-Intensity Training Group): Began with 65% of 1RM in weeks 1-3, increasing to 70% at week 3, and 80% during weeks 5-6.

Both protocols aimed to progressively enhance strength while monitoring the effects on joint stress and overall performance.

Outcome Measures: The primary outcomes included changes in quadriceps and hamstring strength, jump height, and GRF over the intervention period. Secondary outcomes assessed knee joint stress and participant satisfaction with their respective training protocols.

Statistical Analysis: Data were analyzed using XLStat® software (AddinsoftR, Paris, France; version 2019.1.2). Descriptive statistics were calculated for demographic data. Mann-Whitney U tests were used for comparing groups, while Wilcoxon signed-rank tests evaluated within-group differences across time points (ΔM2-M1, ΔM3-M2, and ΔM3-M1). The reliability of measurements was assessed using the Intraclass Correlation Coefficient (ICC).

The study results are expected to provide insights into the effectiveness of BFR as a safer, low-load alternative to traditional high-intensity training in adolescent athletes, potentially offering a means to optimize performance while minimizing injury risk.

Eligibility Criteria:
Inclusion Criteria:

* Aged between 16 and 18 years.
* Engaged in basketball training sessions at least three times per week.
* Competed in basketball within the last six months.
* No major injuries that limit their training session routines.

Exclusion Criteria:

* History or presence of cardiac, pulmonary, or metabolic conditions.
* Presence of vascular disorders in the upper or lower limbs.
* Individuals with coagulation disorders or those undergoing anticoagulant therapy.
* Recent surgeries or chronic conditions contraindicating Blood Flow Restriction (BFR) training.