Increasing set volume relative to baseline does not augment skeletal muscle adaptations when compared to maintenance of baseline training volume in recreationally trained individuals.

Purpose: This study compared the effects of prescribing an increased number of sets relative to baseline (ITV) to a maintenance of baseline training volume (BTV), in previously trained individuals.

Methods: Forty-two adults with more than 6 months of elbow flexion resistance training experience had each arm randomized to either the ITV or BTV condition. Participants performed 2-weekly sessions of unilateral standing dumbbell elbow flexion exercise for 12 weeks, 8 of which were supervised.

Caffeine Abstinence in Habituated Users: Cardiovascular Responses to Exercise With Blood Flow Restriction.

Context: Blood flow restriction resistance exercise studies often require caffeine abstinence to avoid cardiovascular effects that could change the blood flow restriction stimulus. However, effects may be attenuated for habituated users.

Objective: To compare cardiovascular responses to blood flow restriction resistance exercise when habituated users consume or abstain from caffeine.

Comparing the acute responses between a manual and automated blood flow restriction system.

Unlabelled: The purpose of this study was to compare acute responses between manual and automated blood flow restriction (BFR) systems.

Methods: A total of 33 individuals completed this study. On visit 1, arterial occlusion pressure (AOP, mm Hg), cardiovascular responses, and discomfort (RPE-D) were measured with each BFR system at rest.

Post-occlusive reactive hyperemia in habituated caffeine users: Effects of abstaining versus consuming typical doses.

Background: Post-occlusive reactive hyperemia (PORH) typically requires caffeine abstinence. For habitual users, it is unknown if abstinence affects PORH.

Objective: Compare PORH after habitual users consume or abstain from caffeine.

Associations Between Estimates of Arterial Stiffness and Cognitive Functioning in Adults With HIV.

Background: Vascular aging, a precursor of arterial stiffness, is associated with neurocognitive impairment (NCI) and cardiovascular disease. Although HIV is associated with rapid vascular aging, it is unknown whether arterial stiffness mediates changes in cognitive function. We explored whether estimated markers of vascular aging were associated with NCI indices in HIV-positive individuals.

Skeletal Muscle Adaptations to High-Load Resistance Training With Pre-Exercise Blood Flow Restriction.

Hammert, WB, Moreno, EN, Martin, CC, Jessee, MB, and Buckner, SL. Skeletal muscle adaptations to high-load resistance training with pre-exercise blood flow restriction. J Strength Cond Res 37(12): 2381-2388, 2023-This study aimed to determine if blood flow restriction (BFR) could augment adaptations to a high-load training protocol that was inadequate for muscle growth.

Does muscle growth mediate changes in a nonspecific strength task?

The purpose of this study was to determine if muscle growth mediates increases in a strength task which was not directly trained. One hundred fifty-one participants were randomized into control, one-repetition maximum training (1RM-TRAIN), or traditional training (TRAD-TRAIN). Training groups performed isotonic elbow flexion 3x/week for 6 weeks.

A narrative review of the effects of blood flow restriction on vascular structure and function.

Blood flow restriction is growing in popularity as a tool for increasing muscular size and strength. Currently, guidelines exist for using blood flow restriction alone and in combination with endurance and resistance exercise. However, only about 1.

A comparison of variability between absolute and relative blood flow restriction pressures.

Introduction: Recommendations are that blood flow restriction (BFR) be applied relative to arterial occlusion pressure (AOP) to provide a similar stimulus.

Purpose: Compare variability of the change in blood flow, shear rate and discomfort between recommended relative pressures and an absolute pressure.

Methods: During one visit, brachial arterial blood flow was measured in 91 participants using pulse-wave Doppler ultrasonography.

Does performing resistance exercise to failure homogenize the training stimulus by accounting for differences in local muscular endurance?

The prescription of resistance exercise often involves administering a set number of repetitions to be completed at a given relative load. While this accounts for individual differences in strength, it neglects to account for differences in local muscle endurance and may result in varied responses across individuals. One way of potentially creating a more homogenous stimulus across individuals involves performing resistance exercise to volitional failure, but this has not been tested and was the purpose of the present study.

A Retrospective Analysis to Determine Whether Training-Induced Changes in Muscle Thickness Mediate Changes in Muscle Strength.

Objective: To investigate the role of muscle thickness changes on changes in strength following 6 weeks of unaccustomed resistance training, via retrospective analysis.

Methods: 151 participants completed 6 weeks of no intervention (CONTROL), one-repetition maximum training (1RM-TRAIN), or traditional resistance training (TRAD-TRAIN). Groups were assigned by covariate adaptive randomization.

The acute muscular response to passive movement and blood flow restriction.

Purpose: To compare the acute effects of passive movement combined with blood flow restriction (PM + BFR) to passive movement (PM) or blood flow restriction alone (BFR).

Methods: A total of 20 healthy participants completed: time control (TC), PM, BFR and PM + BFR (one per leg, over 2 days; randomized). For PM, a dynamometer moved the leg through 3 sets of 15 knee extensions/flexions (90° at 45°/second).

Limb Occlusion Pressure: A Method to Assess Changes in Systolic Blood Pressure.

Unlabelled: Although often used as a surrogate, comparisons between traditional blood pressure measurements and limb occlusion assessed via hand-held Doppler have yet to be completed. Using limb occlusion pressure as a method of assessing systolic pressure is of interest to those studying the acute effects of blood flow restriction, where the removal of the cuff may alter the physiological response.

Purpose: We sought to determine how changes in limb occlusion pressure track with changes in traditional assessments of blood pressure.

The Basics of Training for Muscle Size and Strength: A Brief Review on the Theory.

The periodization of resistance exercise is often touted as the most effective strategy for optimizing muscle size and strength adaptations. This narrative persists despite a lack of experimental evidence to demonstrate its superiority. In addition, the general adaptation syndrome, which provides the theoretical framework underlying periodization, does not appear to provide a strong physiological rationale that periodization is necessary.

A comparison of acute changes in muscle thickness between A-mode and B-mode ultrasound.

Objective: The purpose of this study was to compare acute changes in muscle thickness (MT) between A-mode and B-mode ultrasound before and after four sets of biceps curls.

Approach: Participants visited the laboratory on two separate occasions. The first visit consisted of paperwork and one repetition maximum (1RM) strength assessment.

Assessing differential responders and mean changes in muscle size, strength, and the crossover effect to 2 distinct resistance training protocols.

The objective of this study was to determine differences in 2 distinct resistance training protocols and if true variability can be detected after accounting for random error. Individuals ( = 151) were randomly assigned to 1 of 3 groups: () a traditional exercise group performing 4 sets to failure; () a group performing a 1-repetition maximum (1RM) test; and () a time-matched nonexercise control group. Both exercise groups performed 18 sessions of elbow flexion exercise over 6 weeks.

Blood flow restriction does not augment low force contractions taken to or near task failure.

Low-load exercise performed to or near task failure appears to result in similar skeletal muscle adaptations as low-load exercise with the addition of blood flow restriction (BFR). However, there may be a point where the training load becomes too low to stimulate an anabolic response without BFR. This study examined skeletal muscle adaptions to very low-load resistance exercise with and without BFR.

Perceptual changes to progressive resistance training with and without blood flow restriction.

The purpose was to examine changes in the perceptual responses to lifting a very low load (15% one repetition maximum (1RM)) with and without (15/0) different pressures [40% (15/40) and 80% (15/80) arterial occlusion pressure] and compare that to traditional high load (70/0) resistance exercise. Ratings of perceived exertion (RPE) and discomfort were measured following each set of exercise. In addition, resting arterial occlusion pressure was measured prior to exercise.

Is muscle growth a mechanism for increasing strength?

Skeletal muscle hypertrophy commonly occurs with repeated bouts of resistance exercise as well as following the administration of exogenous drugs. This increase in muscle size is thought to be mechanistically important for the increase in muscle function. However, at present, there is no experimental evidence that would support any paradigm in which muscle hypertrophy is a mechanism for increasing strength with exercise.

High-pressure blood flow restriction with very low load resistance training results in peripheral vascular adaptations similar to heavy resistance training.

Objective: To investigate vascular adaptations to eight weeks of resistance exercise, with and without different pressures of blood flow restriction (BFR), in the upper and lower body.

Approach: Forty individuals (men  =  20, women  =  20) completed eight weeks of resistance exercise at very low loads (15% of one-repetition maximum (1RM)), with two levels of BFR (40% arterial occlusion pressure (AOP), 80% AOP), without BFR, and 70% of 1RM. Vascular conductance and venous compliance were measured via plethysmography before and following training in the forearms and in the calves.

Acute hemodynamic changes following high load and very low load lower body resistance exercise with and without the restriction of blood flow.

Objective: To examine the acute changes in blood flow and blood pressure of very low load knee extensor exercise (15% one repetition maximum (1RM)) with and without different levels of applied pressure to determine how these effects might differ from high load exercise. We also sought to examine if this differed between men and women.

Approach: A total of 90 participants (45 men, 45 women) were randomized into a very low load condition with no restriction 15/0, (n  =  21), a very low load condition with 40% arterial occlusion pressure (15/40, n  =  23), a very low load condition with 80% arterial occlusion pressure (15/80, n  =  22), and a traditional high load condition (70/0, n  =  24).