Effects of Sex and Cuff Pressure on Physiological Responses during Blood Flow Restriction Resistance Exercise in Young Adults

Abstract

PurposeThe purpose of this study was to examine the physiological responses resulting from an acute blood flow restriction resistance exercise bout with two different cuff pressures in young, healthy men and women.MethodsThirty adults (18–30 yr) completed a bilateral leg extension blood flow restriction bout consisting of four sets (30–15–15–15 repetitions), with cuffs applied at pressures corresponding to 40% and 60% of the minimum arterial occlusion pressure (AOP) needed to completely collapse the femoral arteries. During each of these conditions (40% and 60% AOP), physiological measures of near-infrared spectroscopy (NIRS) and EMG amplitude (EMG AMP) were collected from the dominant or nondominant vastus lateralis. After each set, ratings of perceived exertion (RPE) were collected, whereas only at baseline and at the end of the bout, mean arterial pressure (MAP) was assessed. Separate mixed-factorial ANOVA models were used to examine mean differences in the change in EMG AMP and NIRS parameters during each set. The absolute RPE and MAP values were also examined with separate ANOVAs. A P value ≤0.05 was considered statistically significant.ResultsRegardless of sex or cuff pressure, the change in EMG AMP was lower in set 1 (14.8%) compared with the remaining sets (22.6%–27.0%). The 40% AOP condition elicited the greatest changes in oxy[heme] and deoxy[heme], while also providing lower RPEs. For MAP, there was an effect for time such that MAP increased from preexercise (87.5 ± 4.3 mm Hg) to postexercise (104.5 ± 4.1 mm Hg).ConclusionsThe major findings suggested that the 40% AOP condition permitted the greatest amount of recovery during the interset rest. In addition, there did not seem to be any meaningful sex-related difference in this sample of young healthy adults.

Innovations in the Assessment of Skeletal Muscle Health: A Glimpse into the Future

“…the BFR pressure applied which has been demonstrated to alter the physiological responses [41,43] and discomfort (e.g., higher pressures result in greater discomfort). Therefore, it is imperative that TAOP is determined accurately and precisely.…”

“…Specifically, the safety and effectiveness of BFR exercise has been routinely demonstrated with the implementation of the standard 75 repetition (1 × 30, 3 × 15) scheme [28,40]. Additionally, the exercise is performed at 30 % of 1RM (i. e., a low weight/ resistance) and with the small, inflated cuff set to a pressure corresponding to 40-80 % of arterial occlusion pressure (i. e., approximately 40-80 % of systolic blood pressure) [41,42].…”

“…Typically, this necessitates trained personnel to operate and interpret ultrasound-based readings (i. e., arterial and venous blood flow) with the concomitant modulation of pneumatic pressures. Theoretically, minute variations in the determination of TAOP changes the BFR pressure applied which has been demonstrated to alter the physiological responses [41,43] and discomfort (e. g., higher pressures result in greater discomfort). Therefore, it is imperative that TAOP is determined accurately and precisely.…”

Sex‐specific microvascular and hemodynamic responses to passive limb heating in young adults

“…Investigations of sex differences in microvascular function continue to garner substantial interest, 1–5 especially findings resulting from vascular occlusion tests (VOT) in which near‐infrared spectroscopy (NIRS) devices are used to assess skeletal muscle tissue oxygenation (StO 2 , %) 6–9 . Related to NIRS‐VOT, previous data from our laboratory, 6 as well as from others, 8 have indicated that following transient ischemia, males exhibit faster rates of reoxygenation and greater maximal values (StO 2max ) than females.…”