Arterial and Venous Pressure Dynamics in Blood Flow Restriction Versus Traditional Strength Training

Abstract

Strength training responses are influenced by sets, repetitions, and mechanical load, whereas Blood Flow Restriction (BFR) training adds the variable of temporarily restricting blood flow via a tourniquet. This has intensified scientific discussions regarding the vascular responses and thereby safety of the BFR method. To address these concerns, we investigated intravascular pressure changes during low-load (LL-RT), low-load with BFR (LL-BFR-RT), and high-load (HL-RT) exercise. Ten healthy men (26.8 ± 4.59 years) performed unilateral biceps curls to failure in a randomized cross-over design: (1) LL-RT (30% 1RM), (2) LL-BFR-RT (30% 1RM, 50% LOP), and (3) HL-RT (75% 1RM). Total workload was significantly higher in LL-RT (692 ± 251 kg) compared to LL-BFR-RT (378 ± 58.7 kg) and HL-RT (327 ± 65.1 kg, p < 0.001). In terms of mean values, LL-BFR-RT resulted in higher diastolic and mean arterial pressures during rest periods between sets compared to other conditions (p ≤ 0.02). Both LL-RT and LL-BFR-RT led to longer durations spent at increased diastolic (above 90 mmHg, LL-RT: ~419 s vs. LL-BFR-RT: ~356 s vs. Hl-RT: ~122 s), systolic (above 140 mmHg, LL-RT: ~437 s vs. LL-BFR-RT: ~336 s vs. HL-RT: ~199 s), and mean arterial pressures (above 107 mmHg, LL-RT: ~451 s vs. LL-BFR-RT: ~384 s vs. HL-RT: ~168 s) compared to HL-RT (p ≤ 0.028). Relative to total exercise time, LL-BFR-RT resulted in higher proportion of time spent at elevated diastolic (above 90 mmHg, LL-RT: ~56.5% vs. LL-BFR-RT: ~68.7% vs. Hl-RT: ~33.5%) and mean arterial pressures (above 107 mmHg, LL-RT: ~60.8% vs. LL-BFR-RT: ~74.0% vs. HL-RT: ~45.7%) compared to HL-RT (p ≤ 0.034). Peripheral venous pressure was significantly higher in LL-BFR-RT compared to other conditions (p < 0.001), with both absolute and relative time spent at higher pressures (above 75 mmHg, LL-RT: ~57.0 s and ~ 9.12% vs. LL-BFR-RT: ~424 s and ~ 81.7% vs. HL-RT: ~36.0 s and ~ 8.99%, p ≤ 0.002). Our results suggest that BFR training performed to failure imposes greater arterial and venous stress in the exercising limb compared to high-load training without BFR, particularly due to prolonged exposure to elevated pressures. Further research is needed to assess the potential risks of elevated local arterial and venous pressure responses by frequent BFR use, particularly in populations with pre-existing medical conditions.

Keywords: Kaatsu training; arterial hypertension; vascular adaptation; venous hypertension.

FIGURE 1

Study design. 1RM = one‐repetition‐maximum, LOP = limb‐occlusion‐pressure, HL‐RT = high‐load resistance exercise session, LL‐BFR‐RT = low‐load‐blood‐flow‐restrcition resistance exercise session, LL‐RT = low‐load resistance exercise session.

FIGURE 2

Intravascular pressure during low‐load resistance exercise (LL‐RT), LL‐RT with blood flow restriction (LL‐BFR‐RT), and high‐load resistance exercise (HL‐RT). (A) diastolic blood pressure, (B) systolic blood pressure, (C) mean arterial pressure, (D) peripheral venous pressure. ^«Significantly different from baseline within LL‐RT (p < 0.05), ⁺Significantly different from baseline within LL‐BFR‐RT (p < 0.05), ^¤Significantly different from baseline within HL‐RT (p < 0.05), ^§significant difference between LL‐RT and LL‐BFR‐RT within the respective time point (p < 0.05), ^#significant difference between HL‐RT and LL‐BFR‐RT within the respective time point (p < 0.05), ^&significant difference between LL‐RT and HL‐RT within the respective time point (p < 0.05).

FIGURE 3

Intravascular pressure concentration (left) and distribution (right) profiles expressed as absolute duration [s] during low‐load resistance exercise (LL‐RT), LL‐RT with blood flow restriction (LL‐BFR‐RT), and high‐load resistance exercise (HL‐RT). (A) diastolic blood pressure, (B) systolic blood pressure, (C) mean arterial pressure, (D) peripheral venous pressure. Data are presented as mean values (line plots) with standard deviations (shaded areas). The gray‐shaded areas in the background indicate the specific zones for each intravascular pressure parameter (see Table 1). ^§significant difference between LL‐RT and LL‐BFR‐RT within the respective pressure zone (p < 0.05), ^#significant difference between HL‐RT and LL‐BFR‐RT within the respective pressure zone (p < 0.05), ^&significant difference between LL‐RT and HL‐RT within the respective pressure zone (p < 0.05).

FIGURE 4

Intravascular pressure concentration (left) and distribution (right) profiles expressed as relative proportion of the total training time during low‐load resistance exercise (LL‐RT), LL‐RT with blood flow restriction (LL‐BFR‐RT), and high‐load resistance exercise (HL‐RT). (A) diastolic blood pressure, (B) systolic blood pressure, (C) mean arterial pressure, (D) peripheral venous pressure. Data are presented as mean values (line plots) with standard deviations (shaded areas). The gray‐shaded areas in the background indicate the specific zones for each intravascular pressure parameter (see Table 1). ^§significant difference between LL‐RT and LL‐BFR‐RT within the respective pressure zone (p < 0.05), ^#significant difference between HL‐RT and LL‐BFR‐RT within the respective pressure zone (p < 0.05), ^&significant difference between LL‐RT and HL‐RT within the respective pressure zone (p < 0.05).