Pat R. Vehrs

Vehrs, PR, Cox, K, Heyborne, S, Knotes, E, Broberg, C, Clark, J, Swinson, K, Callahan, C, McDougal, H, and Miller, E. B-Strong and KAATSU bands produce similar patterns of blood flow restriction in the leg. J Strength Cond Res XX(X): 000–000, 2026—B-Strong and KAATSU blood flow restriction (BFR) bands are narrow and made of soft, elastic material with multichambered or segmented bladder designs. Research has yet to compare their ability to regulate blood flow at various set pressures in the leg. Ultrasound was used to measure unoccluded blood flow and blood flow at 4 set pressures (200, 300, 400, and 500 mm Hg) in the leg using B-Strong multichambered BFR bands and KAATSU bands in each of 40 healthy young adults (20 male and 20 female subjects). Unoccluded blood flow was measured before the measurement of blood flow at each set pressure. Blood flow at each set pressure was expressed as a percentage of the paired unoccluded blood flow value. A set pressure of 500 mm Hg was unable to occlude superficial femoral artery blood flow using either band in all subjects. Data were analyzed using a linear mixed-effects model. There were no significant main effects for gender ( p = 0.716) or band ( p = 0.750). There was a significant effect for set pressure ( p < 0.001). Further post hoc pairwise comparisons revealed significant differences in relative blood flow between all combinations of set pressures ( p < 0.006). All 2-way and 3-way interactions were not significant ( p values = 0.524–0.981). B-Strong and KAATSU bands resulted in similar blood flow responses to BFR of the superficial femoral artery in both male and female subjects.

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Introduction: The blood flow responses to blood flow restriction (BFR) with “multi-chambered” BFR bands are not well understood. This study investigated the blood flow responses to four set pressures in the arm and leg using B-Strong BFR bands. Methods: Ultrasound was used to measure unoccluded blood flow prior to measuring blood flow at each of four set pressures (200, 300, 400, 500 mmHg) in the arm and the leg in 60 participants (30 males; 30 females). Results: A set pressure of 500 mmHg was unable to occlude blood flow in both limbs in all participants. Blood flow at each set pressure was expressed relative to the paired measure of unoccluded blood flow. There were no significant sex differences in relative blood flow at each set pressure in either the arm ( p = 0.7088) or the leg ( p = 0.9920). There was a main effect for the blood flow responses between set pressures in the arm ( p < 0.0001) and the leg ( p < 0.0001). In both males and females, paired comparisons indicated that blood flow was significantly different between all set pressures ( p < 0.05), except between 300 and 400 mmHg ( p = 0.0752) in the arm and between set pressures of 200 and 300 mmHg in the leg ( p = 0.2518). Discussion: The wide range of blood flow responses to each set pressure in both limbs presents challenges to determining an effective set pressure to use during BFR training and suggests the possibility of diverse outcomes with BFR training with B-Strong bands. Nevertheless, the wide range of blood flow responses does not preclude muscle adaptations as they are the result of multiple factors. The practical use of using elastic “multi-chambered” BFR bands requires further investigation to guide the determination of effective set pressures during exercise.

The use of blood flow restriction (BFR) during low-load resistance training can be efficacious for load-compromised individuals in a variety of clinical, athletic, and fitness settings. Because of the potential benefits to the use of BFR during resistance training, its safe and effective use is of growing interest for practitioners and BFR enthusiasts. The ischemia and hypoxia imposed by partial BFR contributes to the metabolic stress and motor unit recruitment patterns that lead to favorable adaptations in muscle size and strength. There is also a theoretical increased risk of adverse events above that of resistance training without the use of BFR. Organizations such as the National Strength and Conditioning Association and the American College of Sports Medicine have not published position statements or guidelines on the safe and effective use of BFR during training. This article presents a science and research–based practical guide that informs strength and conditioning practitioners how to modify training variables to mitigate the risks associated with resistance training with BFR. Following science-based recommendations and reducing perceived discomfort can improve tolerance to BFR training and adherence to a BFR training program.

Vehrs, PR, Richards, S, Nielsen, JR, Gardner, SD, DeSpain, N, Watkin, JH, Witney, T, Snow, GL, and Hager, RL. Blood flow at different occlusion pressures using multichambered blood flow restriction cuffs in the arm and leg. J Strength Cond Res XX(X): 000–000, 2026—The blood flow responses to increasing cuff pressure when using multichambered blood flow restriction (BFR) cuffs are not well understood. On 2 nonconsecutive days, ultrasound was used to measure unoccluded blood flow and blood flow at 8 cuff pressures in the arm (150–500 mm Hg) and 6 cuff pressures in the leg (250–500 mm Hg) using B Strong multichambered BFR cuffs in 20 healthy young adults (10 men, 10 women). Despite differences in limb circumferences, a cuff pressure of 500 mm Hg was unable to occlude blood flow in both limbs in men and women. Across the range of cuff pressures, there were significant sex differences ( p < 0.0001) in absolute (ml·min ⁻¹ ) and relative (% unoccluded) blood flow in the arm and absolute blood flow in the leg. Inflation of B Strong cuffs was unable to significantly reduce unoccluded absolute blood flow (ml·min ⁻¹ ) in the arm at all cuff pressures ( p = 0.2148–0.99). Relative blood flow in the arm was significantly reduced at all cuff pressures ( p < 0.0001) and a plateau ( p = 0.3771–0.99) occurred at cuff pressures of 200 mm Hg and above in men and 250 mm Hg and above in women. In the leg, only cuff pressures of 400 mm Hg and above ( p < 0.045) for men and 450 mm Hg and above ( p < 0.0001) in women significantly reduced absolute blood flow below unoccluded values. There was a plateau in relative blood flow between cuff pressures of 250–450 mm Hg in men and women ( p = 0.1041–0.99). Because of the wide variability in blood flow responses to increasing cuff pressures, people may have diverse experiences and outcomes with BFR training. This presents new challenges to prescribing exercise with BFR. The practical limitations of using multichambered BFR cuffs require further investigation.

Context: It is recommended that arterial occlusion pressure (AOP) should be measured prior to the use of blood flow restriction training. Previous studies have not compared measures of AOP when using 2 methods of cuff inflation commonly reported in the literature. Design: A cross-sectional observational study was used to compare the measurement of brachial artery AOP as measured using pulse wave Doppler ultrasound (PWDOP) and continuous wave Doppler ultrasound (CWDOP) devices when inflating the cuff with a research/clinical-grade Hokanson (HOK) rapid cuff inflation system and manually (MAN) with a hand pump and gauge. Methods: We made simultaneous measures of brachial artery AOP in 20 males and 21 females using PWDOP and CWDOP devices when using HOK and MAN cuff inflation methods. Data were analyzed with a linear mixed model analysis of variance and Bland–Altman plots. Results: There was not a significant main effect for the overall differences in AOP as measured using PWDOP (121.7 ± 14.7 mmHg) and CWDOP (121.3 ± 14.5 mmHg; P = .3641). There was a significant overall main effect for AOP measured using the HOK (122.7 ± 14.6 mmHg) and MAN (120.3 ± 14.6 mmHg) cuff inflation methods (P < .0001) and between males (128.2 ± 13.7 mmHg) and females (115.2 ± 12.5 mmHg; P = .0034). Bland–Altman plots revealed minimal bias and reasonable limits of agreement between PWDOP and CWDOP measures of AOP when using HOK (0.8 mmHg; 95% CI, −4.7 to 3.0 mmHg) and MAN (0.4 mmHg; 95% CI, −5.3 to 4.5 mmHg) cuff inflation methods. Conclusions: The cessation of an audible pulse using CWDOP is in agreement with the complete obstruction of the arterial blood flow observed using PWDOP. Although statistically significant, small differences in PWDOP and CWDOP measures of AOP when using HOK and MAN cuff inflation methods are of little practical significance. A hand-held CWDOP device and a handpump/gauge can be used to measure AOP.

Arterial occlusion pressure (AOP) is influenced by the characteristics of the cuff used to measure AOP. Doppler ultrasound was used to measure AOP of the brachial and superficial femoral arteries using straight and curved blood flow restriction cuffs in 21 males and 21 females. Vessel diameter and blood flow were evaluated as independent predictors of AOP. Overall, there were no significant differences in AOP when using the straight and curved cuffs in the brachial (129 mmHg vs. 128 mmHg) or superficial femoral artery (202 mmHg vs. 200 mmHg), respectively. Overall, AOP was greater (p < 0.05) in males than in females in the arm (135 mmHg, 123 mmHg) and leg (211 mmHg, 191 mmHg). Brachial (0.376 mm, 0.323 mm) and superficial femoral (0.547 mm, 0.486 mm) arteries were larger (p = 0.016) in males than in females, respectively. Systolic blood pressure (SBP) and arm circumference were predictive of brachial artery AOP, whereas SBP, diastolic blood pressure, thigh circumference, and vessel diameter were predictive of superficial femoral artery AOP. Straight and curved cuffs are efficacious in the measurement of AOP in the arm and leg. Differences in vessel size may contribute to sex differences in AOP but this requires further investigation.

Vehrs, PR, Reynolds, S, Allen, J, Barrett, R, Blazzard, C, Burbank, T, Hart, H, Kasper, N, Lacey, R, Lopez, D, and Fellingham, GW. Measurements of arterial occlusion pressure using hand-held devices. J Strength Cond Res 38(5): 873–880, 2024—Arterial occlusion pressure (AOP) of the brachial artery was measured simultaneously using Doppler ultrasound (US), a hand-held Doppler (HHDOP), and a pulse oximeter (PO) in the dominant (DOM) and nondominant (NDOM) arms of males (n = 21) and females (n = 23) using continuous (CONT) and incremental (INCR) cuff inflation protocols. A mixed-model analysis of variance revealed significant (p < 0.05) overall main effects between AOP measured using a CONT (115.7 ± 10.9) or INCR (115.0 ± 11.5) cuff inflation protocol; between AOP measured using US (116.3 ± 11.2), HHDOP (115.4 ± 11.2), and PO (114.4 ± 11.2); and between males (120.7 ± 10.6) and females (110.5 ± 9.4). The small overall difference (1.81 ± 3.3) between US and PO measures of AOP was significant (p < 0.05), but the differences between US and HHDOP and between HHDOP and PO measures of AOP were not significant. There were no overall differences in AOP between the DOM and NDOM arms. Trial-to-trial variance in US measurements of AOP was not significant when using either cuff inflation protocol but was significant when using HHDOP and PO and a CONT cuff inflation protocol. Bland-Altman plots revealed reasonable limits of agreement for both HHDOP and PO measures of AOP. The small differences in US, HHDOP, and PO measurements of AOP when using CONT or INCR cuff inflation protocols are of minimal practical importance. The choice of cuff inflation protocol is one of personal preference. Hand-held Doppler of PO can be used to assess AOP before using blood flow restriction during exercise.