Abstract / Summary
Background Blood flow restriction (BFR) training is used to partially restrict limb blood flow during exercise. Practical blood flow restriction (pBFR) applications often rely on subjective pressure scales; however, the extent to which perceived compression levels influence arterial blood flow remains unclear. This study aimed to examine changes in popliteal artery blood flow velocity across different subjective compression levels during pBFR. Methods This cross-sectional observational study included 42 healthy physically active adults (18–37 years). pBFR was applied to the dominant thigh using a 5 cm elastic band wrapped twice around the proximal thigh. Participants reported perceived compression as free flow (0/10), light (3–4/10), moderate (6–7/10), and high (9–10/10). Popliteal artery blood flow velocity and vessel diameter were measured using Doppler ultrasound. Repeated-measures ANOVA was used to compare outcomes across compression levels. Pearson correlation analyses were performed to examine associations among blood flow velocity, thigh circumference, and skinfold thickness. Analyses were conducted using pooled male and female data. Results Blood flow velocity progressively decreased with increasing compression. Significant differences were observed between all compression levels (p < 0.001). Blood flow velocity values were significantly correlated across compression levels. No significant associations were found between anthropometric measures and blood flow velocity. Complete arterial occlusion was not observed in any participant. Conclusions Subjective pBFR compression levels were associated with graded reductions in popliteal artery blood flow velocity under the present experimental conditions. These findings reflect acute hemodynamic responses at rest and should not be generalized to exercise adaptations. Anthropometric characteristics were not associated with blood flow responses. Further research is needed to determine the translational relevance of subjective compression levels during exercise.