Methodological Considerations When Studying Resistance-Trained Populations: Ideas for Using Control Groups.

Hammert, WB, Dankel, SJ, Kataoka, R, Yamada, Y, Kassiano, W, Song, JS, and Loenneke, JP. Methodological considerations when studying resistance-trained populations: Ideas for using control groups. J Strength Cond Res 38(12): 2164-2171, 2024-The applicability of training effects from experimental research depends on the ability to quantify the degree of measurement error accurately over time, which can be accounted for by including a time-matched nonexercise control group.

Investigating the Influence of Limb Blood Flow on Contraction-Induced Muscle Growth and the Impact of that Growth on Changes in Maximal Strength.

Abstract: Changes in skeletal muscle size may be affected by resting blood flow (e.g., nutrient delivery) and this change in size is a hypothesized mechanism for changes in strength.

Does Unilateral High-Load Resistance Training Influence Strength Change in the Contralateral Arm Also Undergoing High-Load Training?

Training one limb with a high-load has been shown to augment strength changes in the opposite limb training with a low-load (via cross-education of strength), indicating that within-subject models can be problematic when investigating strength changes. This study examined if the cross-education of strength from unilateral high-load training could augment the strength changes in the opposite arm undergoing the same unilateral high-load training. 160 participants were randomized to one of four groups: (1) training on the dominant arm followed by the non-dominant arm (D + ND), (2) training on the dominant arm only (D-Only), (3) training on the non-dominant arm only (ND-Only), and (4) a non-exercise control.

The Effect of Isometric Handgrip Training With and Without Blood Flow Restriction on Changes in Resting Blood Pressure.

To investigate the effects of high-intensity contractions and low-intensity contractions with and without blood flow restriction on changes in blood pressure and hemodynamic parameters. A total of 179 participants (18-35 years) were randomly assigned to one of three training groups that exercised 3 times per week for six weeks or a non-exercise control group. The groups are as follows: 1) Control [CON,  = 44]; 2) completed 4 sets of two-minute isometric contractions at 30% maximal voluntary contraction [LI,  = 47]; 3) completed 4 sets of two-minute isometric contractions at 30% maximal voluntary contraction with a 12 cm cuff inflated to 50% of arterial occlusion pressure [LI+BFR,  = 41]; or 4) completed 4 maximal isometric contractions lasting 5 seconds [MAX,  = 47].

Limb dominance does not have a meaningful impact on arterial occlusion pressure.

Introduction: Limb dominancy has been suggested, by some, to influence arterial occlusion pressure (AOP). However, we hypothesized that the differences in AOP between the dominant and nondominant legs were more likely explained by differences in cuff position.

Aims: To determine the impact of limb dominance, composition, and cuff position on AOP in the context of error associated with measuring AOP twice on the same leg.

Progression of total training volume in resistance training studies and its application to skeletal muscle growth.

Progressive overload describes the gradual increase of stress placed on the body during exercise training, and is often quantified (i.e. in resistance training studies) through increases in total training volume (i.

Unilateral high-load resistance training induced a similar cross-education of strength between the dominant and non-dominant arm.

It was previously hypothesized that the cross-education of strength is asymmetrical, where a greater transfer of strength is observed from the dominant to the non-dominant limb. The purpose of this study was to examine if the magnitude of cross-education of strength differed between dominant and non-dominant limbs following unilateral high-load resistance training. One hundred and twenty-two participants were randomized to one of the three groups: 1) training on the dominant arm (D-Only), 2) training on the non-dominant arm (ND-Only) and 3) a time-matched non-exercise control (Control).

Individuals Can be Taught to Sense the Degree of Vascular Occlusion: Implications for Practical Blood Flow Restriction.

Song, JS, Hammert, WB, Kataoka, R, Yamada, Y, Kang, A, and Loenneke, JP. Individuals can be taught to sense the degree of vascular occlusion: Implications for practical blood flow restriction. J Strength Cond Res 38(8): 1413-1418, 2024-It is currently unknown if individuals can be conditioned to a relative arterial occlusion pressure (AOP) and replicate that pressure at a later time point.

Cross-Education of Muscular Endurance: A Scoping Review.

Background: It is well established that performing unilateral resistance training can increase muscle strength not only in the trained limb but also in the contralateral untrained limb, which is widely known as the cross-education of strength. However, less attention has been paid to the question of whether performing unilateral resistance training can induce cross-education of muscular endurance, despite its significant role in both athletic performance and activities of daily living.

Objectives: The objectives of this scoping review were to provide an overview of the existing literature on cross-education of muscular endurance, as well as discuss its potential underlying mechanisms and offer considerations for future research.

Blood flow restriction augments exercise-induced pressure pain thresholds over repetition and effort matched conditions.

We sought to determine the effects of blood flow restriction (BFR) on exercise-induced hypoalgesia, specifically using low-load (LL) resistance exercise (30% 1RM) protocols that accounted for each individual's local muscular endurance capabilities. Forty-four participants completed four conditions: (1) 70% of maximal BFR repetitions with blood flow restriction (LL+BFR exercise); (2) 70% maximal BFR repetitions without LL+BFR (LL exercise); (3) 70% maximal free flow repetitions (LL+EFFORT exercise); (4) time-matched, non-exercise control (CON). Pressure pain threshold (PPT) was measured before and after exercise.

Blood flow restriction pressure for narrow cuffs (5 cm) cannot be estimated with precision.

Blood flow restriction pressures are set relative to the lowest pressure needed to occlude blood flow with that specific cuff. Due to pressure limitations of some devices, it is often not possible to occlude blood flow in all subjects and apply a known relative pressure in the lower body with a 5 cm wide cuff..

Blood flow restriction augments the cross-education effect of isometric handgrip training.

Introduction: The application of blood flow restriction (BFR) to low-intensity exercise may be able to increase strength not only in the trained limb but also in the homologous untrained limb. Whether this effect is repeatable and how that change compares to that observed with higher intensity exercise is unknown.

Purpose: Examine whether low-intensity training with BFR enhances the cross-education of strength compared to exercise without BFR and maximal efforts.

The Plateau in Muscle Growth with Resistance Training: An Exploration of Possible Mechanisms.

It is hypothesized that there is likely a finite ability for muscular adaptation. While it is difficult to distinguish between a true plateau following a long-term training period and short-term stalling in muscle growth, a plateau in muscle growth has been attributed to reaching a genetic potential, with limited discussion on what might physiologically contribute to this muscle growth plateau. The present paper explores potential physiological factors that may drive the decline in muscle growth after prolonged resistance training.

Improved interference control after exercise with blood flow restriction and cooling is associated with but not mediated by increased lactate.

Background: To evaluate the effects of recumbent sprint interval exercise with and without blood flow restriction and body cooling on interference control and whether the changes in interference control can be explained by the changes in blood lactate.

Methods: 85 participants (22 SD 3 years old) completed 1 familiarization visit and then 5 experimental visits in a randomized order: exercise only (Ex), exercise with blood flow restriction (ExB), exercise with cooling (ExC), and exercise with blood flow restriction and cooling (ExBC), and non-exercise control (Con). Measurements of blood lactate and the Stroop Color Word Test were performed before and after exercise.

Unilateral high-load resistance training influences strength changes in the contralateral arm undergoing low-load training.

Objectives: Within-subject training models have become common within the exercise literature. However, it is currently unknown if training one arm with a high load would impact muscle size and strength of the opposing arm training with a low load.

Design: Parallel group.

Clinical and Magnetic Resonance Imaging Outcomes After Human Cord Blood-Derived Mesenchymal Stem Cell Implantation for Chondral Defects of the Knee.

Background: There is a paucity of literature reporting clinical and magnetic resonance imaging (MRI) outcomes after allogeneic umbilical cord blood-derived mesenchymal stem cell (UCB-MSC) implantation for chondral defects of the knee.

Purpose: To report clinical and MRI outcomes after UCB-MSC implantation for chondral lesions of the knee.

Study Design: Case series; Level of evidence, 4.

Effect of Increased Pressure Pain Threshold on Resistance Exercise Performance With Blood Flow Restriction.

Kataoka, R, Song, JS, Bell, ZW, Wong, V, Spitz, RW, Yamada, Y, and Loenneke, JP. Effect of increased pressure pain threshold on resistance exercise performance with blood flow restriction. J Strength Cond Res 37(6): 1204-1210, 2023-This study aimed to examine whether increasing pressure pain threshold (PPT) through isometric handgrip exercise (HG) affects the number of repetitions completed and discomfort with knee extension exercise (KE) with blood flow restriction (BFR), and examine whether performing additional exercise leads to a further increase in PPT.

Effects of low-intensity resistance exercise with blood flow restriction after high tibial osteotomy in middle-aged women.

Background: High tibial osteotomy (HTO) is an effective surgical method for treating medial compartment osteoarthritis. However, in most cases after surgery, muscle strength is decreased, and rapid muscle atrophy is observed. Therefore, the purpose of this study is to verify the effects of low-intensity resistance exercise (LIE) with blood flow restriction (BFR) on the cross-sectional area (CSA) of thigh muscles, knee extensor strength, pain, and knee joint function and investigate proper arterial occlusion pressure (AOP) in middle-aged women who underwent HTO.

Potential considerations with estimating blood flow restriction pressure in the lower body using a narrower cuff.

Blood flow restriction pressures are typically set as a percentage of the arterial occlusion pressure. For those who do not have the ability to measure the arterial occlusion pressure, estimation equations are available. However, notable considerations are needed when estimating pressure with a narrow cuff (5 cm) in the lower body.

Repair of a large patellar cartilage defect using human umbilical cord blood-derived mesenchymal stem cells: A case report.

Background: Patellar dislocation may cause cartilage defects of various sizes. Large defects commonly require surgical treatment; however, conventional treatments are problematic.

Case Summary: A 15-year-old male with a large patellar cartilage defect due to patellar dislocation was treated human umbilical cord blood-derived mesenchymal stem cell (hUCB-MSC) implantation.