Effects of Blood Flow Restriction and Small-Sided Games on Soccer Passing and Dribbling Stability Under Fatigue

Beijing Sport University40 enrolled

Overview

This study aims to investigate whether applying blood flow restriction (BFR) during small-sided soccer games (SSG) can help soccer players maintain their passing and dribbling stability when they are fatigued. The study includes 40 young male soccer players. Participants will be randomly divided into two groups: One group will wear pressurized BFR cuffs on their legs (80% of limb occlusion pressure) during a 4v4 training game. The other group will act as a control, wearing the same cuffs but without any pressure (0% pressure) during the exact same training game.Both groups will complete a 6-week training program, practicing 3 times a week. Before and after the 6-week period, researchers will test the players' physical and technical skills (such as jumping, passing, and dribbling). Importantly, these tests will be conducted both before and immediately after a tiring 45-minute exercise routine to see which training method is more effective at preventing performance drops caused by fatigue.

This study utilizes a randomized, single-blind, placebo-controlled parallel group design. A total of 40 young male soccer players with systematic training backgrounds will be recruited. Following baseline testing, participants will be randomly assigned to either the BFR-SSG group or the SSG control group.The intervention spans 6 weeks, featuring three standardized 90-minute training sessions per week. The core intervention consists of a 4v4 small-sided game module (4 sets of 4 minutes). During this module, the BFR-SSG group will wear pneumatic cuffs inflated to 80% of their individual Limb Occlusion Pressure (LOP), while the control group will wear uninflated cuffs (0% LOP).Pre- and post-intervention assessments will systematically evaluate physiological adaptations (blood lactate, creatine kinase) , neuromuscular function (Countermovement Jump) , and sport-specific technical stability (Loughborough Soccer Passing Test and a 20m change-of-direction dribbling test). To specifically assess performance under metabolic stress, the technical and neuromuscular tests will be conducted at baseline and immediately following a standardized 45-minute fatigue-inducing protocol (Modified LIST). The primary goal is to quantify the attenuation rate of passing and dribbling performance under fatigue and determine if BFR combined with SSG provides superior chronic adaptations compared to SSG alone

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Interventions

Blood Flow Restriction + Small-Sided Games (BFR-SSG)BEHAVIORAL

The intervention lasts for 6 weeks, with 3 standardized 90-minute soccer training sessions per week. During the core 20-minute intervention module, participants play 4v4 small-sided games (4 sets of 4 minutes, with 2 minutes of rest between sets). Cuffs are inflated to 80% LOP during the exercise phase and fully deflated during the rest intervals.

Small-Sided Games (SSG) ControlBEHAVIORAL

Participants complete the identical 6-week standardized soccer training program (3 sessions per week) and the 4v4 small-sided games module. However, the cuffs worn by the participants remain at 0% LOP (uninflated) throughout the entire duration of the small-sided games.

Eligibility

Sex: MALEMin age: 18 YearsMax age: 30 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Young male soccer players. Possess a systematic soccer specific training background and maintain a stable competitive state. Cleared by the Physical Activity Readiness Questionnaire (PAR-Q), confirming that cardiovascular and metabolic systems can tolerate high-intensity physical testing and blood flow restriction interventions. Exclusion Criteria: * Any recent history of neuromuscular or musculoskeletal system injuries. Current smoking habit. Consumption of any sports nutrition supplements or drinks that could significantly affect muscle performance or neural excitability (e.g., creatine, caffeine, beta-alanine) within 3 months prior to the start of the study and throughout the experimental period.

Outcomes

Primary Outcomes

Loughborough Soccer Passing Test (LSPT) Performance

The LSPT assesses passing skill and stability. The score is the total time (in seconds) required to complete 16 passes, plus penalty time added for passing errors. To evaluate passing stability under fatigue, the performance attenuation rate is calculated by comparing scores obtained before and immediately after a standardized 45-minute fatigue-inducing protocol (Modified LIST).

Time frame: Baseline (Week 0) and immediately post-intervention (Week 6). At both time points, the test is performed pre-fatigue and immediately post-fatigue.

20m Change-of-Direction Dribbling Test Technical Deficit

This test evaluates high-speed dribbling stability over a 20m slalom course. The primary metric is the "technical deficit," calculated by subtracting the time taken to complete the course without the ball (sprint) from the time taken with the ball (dribbling). This isolates technical stability from pure physical fatigue.

Time frame: Baseline (Week 0) and immediately post-intervention (Week 6). At both time points, measured pre-fatigue and immediately post-fatigue.

Secondary Outcomes

Countermovement Jump (CMJ) Height

Maximum vertical jump height (in centimeters) measured using a 3D force plate. It evaluates the attenuation of lower limb neuromuscular function and explosive power under metabolic stress.

Time frame: Baseline (Week 0) and immediately post-intervention (Week 6). Measured pre-fatigue and immediately post-fatigue at both time points.

Yo-Yo Intermittent Recovery Test Level 1 (YYIRT-1) Distance

Total running distance (in meters) completed before exhaustion to assess chronic adaptations in soccer-specific intermittent endurance.

Time frame: Baseline (Week 0) and post-intervention (Week 6). Tests are conducted on a separate day, at least 48 hours apart from the main testing day, to avoid residual fatigu

Creatine Kinase (CK) Concentration

Absolute creatine kinase concentration (U/L) measured from fingertip capillary blood to evaluate skeletal muscle micro-damage and chronic adaptation

Time frame: Fasting baseline (Week 0), 24 hours after the first intervention session (Week 1), and 24 hours after the final intervention session (Week 6).