Lower Extremity Blood Flow Restriction Training in Athletes Significantly Improves Strength‐Related Outcomes in 58% of Studies Compared to Non‐Blood Flow Restriction Control

PURPOSE: To examine the role of lower extremity blood flow restriction (BFR) in the athletic population. METHODS: This study was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines. Searches of Level I and II studies were performed on PubMed, Embase, and Cochrane databases. Article identification was performed in August 2024. Studies related to BFR in the lower extremity in athletic populations were included. The data collected included athlete demographics; treatment groups; BFR training protocols; control training protocol; exercises performed; training duration and frequency; cuff type, size, and pressure; muscles targeted; strength improvement; endurance improvement; muscle growth; and sport-specific metrics (speed, jump height, etc.). RESULTS: Twenty studies were identified for inclusion. Significant within-group strength increases from pre- to post-training in the BFR group were reported in 19 of 20 studies, with at least 1 strength outcome being significantly increased in the BFR group compared to the control group in 11 of 19 studies (58%). Outcomes related to muscle size were reported in 14 studies, with 10 of these studies reporting within-group increases for the BFR group in at least 1 muscle size metric. Sport-specific metrics were reported in 12 studies, and 4 studies reported on endurance outcomes and generally favored the BFR group over the control group. Five of 6 studies comparing low-load exercise with BFR to high-load exercise without BFR reported comparable outcomes between groups. CONCLUSIONS: In this systematic review, we found that 58% of studies reporting on lower extremity BFR use in athletes observed significant strength improvements in the BFR group compared to a non-BFR group. Additionally, when comparing low-intensity exercise with BFR to high-intensity exercise without BFR, 5 of 6 studies reported either improved or comparable outcomes between the BFR and control groups. In general, exercise with and without BFR led to improvements in lower extremity strength, muscle size, endurance outcomes, and sport-specific metrics, and most of the included studies reported greater improvements within the BFR group. LEVEL OF EVIDENCE: Level II, systematic review of Level I and II studies.