Combined effects of blood flow restriction training and nutritional intervention on muscle adaptations: a systematic review and meta-analysis

BackgroundBlood flow restriction (BFR) training induces muscle hypertrophy and strength gains under low-load conditions by restricting blood flow. While BFR reduces mechanical stress on joints, the associated metabolic stress and discomfort may limit training performance. Certain nutritional supplements may enhance BFR training effects, but the existing evidence remains inconclusive.ObjectiveTo systematically evaluate the combined effects of BFR training and nutritional interventions on maximal strength, muscular endurance, and muscle hypertrophy in healthy adults.MethodsA systematic search was conducted in PubMed, Web of Science, Embase, Cochrane Library, and Scopus databases from January 2015 to December 2025, following PRISMA guidelines. Randomized controlled trials comparing BFR combined with nutritional interventions versus BFR alone (or BFR plus placebo) were included. Standardized mean differences (SMD) and 95% confidence intervals (CIs) were calculated using a random-effects model.ResultsNine studies involving 181 healthy adults were included. Meta-analysis showed no clear additional effect of nutritional interventions on maximal strength (SMD = −0.09; 95% CI: −0.37, 0.20; p = 0.55) or muscle hypertrophy (SMD = 0.31; 95% CI: −0.14, 0.77; p = 0.18). Nutritional interventions were associated with improvements in muscular endurance (SMD = 0.90; 95% CI: 0.55, 1.25; p < 0.00001), although the limited number of studies and small sample sizes warrant cautious interpretation. Subgroup analyses indicated no significant influence of supplement type, participant training status, or intervention duration on maximal strength.ConclusionCurrent evidence suggests that nutritional interventions may support fatigue resistance and enhance muscular endurance under BFR training conditions, but do not provide a clear additional benefit for maximal strength or hypertrophy. These findings should be interpreted cautiously due to the limited number of studies, small sample sizes, and heterogeneity in supplementation protocols. Further high-quality research is needed to explore long-term effects, mechanisms, and population-specific responses, including female and elderly participants.