Publications by authors named "Robert Spitz"

Purpose Of The Review: The role of leptin in regulating cardiac function is still controversial with conflicting results in clinical and preclinical studies. However, most previous studies have not considered leptin's powerful cardiac effects that are mediated via activation of central nervous system (CNS) leptin receptors (LepRs) which, in turn, elicit major improvements in cardiac metabolism. In this review, we focus mainly on the role of leptin in regulating cardiac function via its CNS LepRs and downstream signaling pathways, such as the brain melanocortin system.

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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.

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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.

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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].

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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.

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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).

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VT-1598 is a novel fungal CYP51 inhibitor and 1-tetrazole-based antifungal drug candidate with improved selectivity minimizing off-target binding to and inhibition of human CYP450 enzymes. Data are presented from this first clinical study in the evaluation of the safety and pharmacokinetic (PK) of single ascending doses of 40, 80, 160, 320, and 640 mg VT-1598, comprising a 160 mg cohort in both fasting and fed states. Eight healthy adults per dose were randomized to receive either oral VT-1598 or placebo (3:1).

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Article Synopsis
  • The study aimed to investigate the asymmetrical transfer of strength between dominant and non-dominant limbs during unilateral training, challenging the prevailing belief in the dominance of this effect.
  • A thorough literature search identified only three relevant studies, which provided limited evidence to support the hypothesis that training one limb significantly strengthens the other.
  • The findings suggested a minimal effect of training the dominant limb on the non-dominant limb's strength, indicating the need for more comprehensive research to clarify this relationship.
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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.

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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..

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Article Synopsis
  • The study investigated how different levels of ischemic preconditioning pressures (110% and 150% of arterial occlusion pressure) affected pain sensitivity (measured as pressure pain threshold) and resistance exercise performance in 39 subjects.
  • Both ischemic preconditioning pressures increased pain thresholds compared to a control and sham group but caused more discomfort, especially at 150%, without affecting overall exercise performance metrics like total work or peak torque.
  • The researchers concluded that the changes in pain sensitivity did not translate to improvements in exercise performance, suggesting that a higher threshold of pressure might be necessary for potential benefits of ischemic preconditioning.
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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.

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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.

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Article Synopsis
  • * The study aims to review existing research on how regular exercise training affects exercise-induced hypoalgesia and explore possible mechanisms behind any changes.
  • * There is a lack of thorough randomized controlled trials in this area, making it unclear how exercise training might enhance exercise-induced hypoalgesia; future research should include relevant control groups and standardized exercise protocols.
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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.

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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.

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Lower urinary tract symptoms (LUTS) refer to various urological diseases, and incomplete bladder emptying is common among affected patients. The etiology of LUTS is largely unknown, and investigations of LUTS suggest that bladder fibrosis contributes to pathogenesis of LUTS. MicroRNAs (miRNAs) are short (∼22 nucleotides), non-coding RNAs that repress target gene expression by a combination of mRNA degradation and translation inhibition.

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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.

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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.

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Article Synopsis
  • - Concerns have been raised about the two-sex binary in sports, with the thesis arguing that categorizing athletes based on muscle size instead could eliminate inherent strength advantages between genders.
  • - The study analyzed data from 16 different sets involving 963 participants, matching males and females with similar muscle thickness to evaluate strength performances across various contraction types.
  • - Findings revealed that 76%-88% of strength measurements favored males, even when muscle size was accounted for, suggesting that using muscle mass as a classification in strength sports may not ensure fair competition.
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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.

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Bell, ZW, Spitz, RW, Wong, V, Yamada, Y, Song, JS, Abe, T, and Loenneke, JP. Can individuals be taught to sense the degree of vascular occlusion? A comparison of methods and implications for practical blood flow restriction. J Strength Cond Res 36(12): 3359-3365, 2022-The study objective was to determine whether subjects could be conditioned to a relative blood flow restriction pressure in the lower body and compare 2 separate conditioning methods (unconstrained vs.

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Background: Isotonic exercise is the most common mode of strength training. Isotonic strength is often measured in the movement that was exercised, but isometric and isokinetic movements are also commonly used to quantify changes in muscular strength. Previous research suggests that increasing strength in one movement may not lead to an increase in strength in a different movement.

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It is well-established that a single bout of exercise can reduce pain sensitivity (i.e., exercise-induced hypoalgesia) in healthy individuals.

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To 1) examine whether blood flow restriction would provide an additional exercise-induced hypoalgesic response at an upper and lower limb when it is incorporated with low-load resistance exercise until failure, and 2) examine if increases in blood pressure and discomfort, with blood flow restricted exercise, would mediate the exercise-induced hypoalgesia over exercise without blood flow restriction. Forty healthy young participants completed two trials: four sets of unilateral knee extension exercise to failure at 30% of one-repetition maximum, with and without blood flow restriction. Pressure pain thresholds were assessed before (twice) and 5-min post exercise at an upper and lower limb.

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