Joseph P. Weir

Eight weeks of supplementation with a multi-ingredient weight loss product enhances body composition, reduces hip and waist girth, and increases energy levels in overweight men and women

BackgroundNumerous natural products are marketed and sold claiming to decrease body weight and fat, but few undergo finished product-specific research demonstrating their safety and efficacy.ObjectiveTo determine the safety and efficacy of a multi-ingredient supplement containing primarily raspberry ketone, caffeine, capsaicin, garlic, ginger and Citrus aurantium (Prograde Metabolism™ [METABO]) as an adjunct to an eight-week weight loss program.MethodsUsing a randomized, placebo-controlled, double-blind design, 70 obese but otherwise healthy subjects were randomly assigned to METABO or a placebo and underwent 8u2009weeks of daily supplementation, a calorie restricted diet, and exercise training. Subjects were tested for changes in body composition, serum adipocytokines (adiponectin, resistin, leptin, TNF-α, IL-6) and markers of health including heart rate and blood pressure.ResultsOf the 45 subjects who completed the study, significant differences were observed in: body weight (METABO -2.0% vs. placebo -0.5%, Pu2009<u20090.01), fat mass (METABO -7.8 vs. placebo -2.8%, Pu2009<u20090.001), lean mass (METABO +3.4% vs. placebo +0.8%, Pu2009<u20090.03), waist girth (METABO -2.0% vs. placebo -0.2%, Pu2009<u20090.0007), hip girth (METABO -1.7% vs. placebo -0.4%, Pu2009<u20090.003), and energy levels per anchored visual analogue scale (VAS) (METABO +29.3% vs. placebo +5.1%, Pu2009<u20090.04). During the first 4u2009weeks, effects/trends for maintaining elevated serum leptin (Pu2009<u20090.03) and decreased serum resistin (Pu2009<u20090.08) in the METABO group vs. placebo were also observed. No changes in systemic hemodynamics, clinical blood chemistries, adverse events, or dietary intake were noted between groups.ConclusionsMETABO administration is a safe and effective adjunct to an eight-week diet and exercise weight loss program by augmenting improvements in body composition, waist and hip girth. Adherence to the eight-week weight loss program also led to beneficial changes in body fat in placebo. Ongoing studies to confirm these results and clarify the mechanisms (i.e., biochemical and neuroendocrine mediators) by which METABO exerts the observed salutary effects are being conducted.

Effects of 6 Weeks of Aerobic Exercise Combined With Conjugated Linoleic Acid on the Physical Working Capacity at Fatigue Threshold

Abstract Jenkins, NDM, Buckner, SL, Baker, RB, Bergstrom, HC, Cochrane, KC, Weir, JP, Housh, TJ, and Cramer, JT. Effects of 6 weeks of aerobic exercise combined with conjugated linoleic acid on the physical working capacity at fatigue threshold. J Strength Cond Res 28(8): 2127–2135, 2014—The purpose of this study was to examine the effects of conjugated linoleic acid (CLA) supplementation in conjunction with 6 weeks of aerobic exercise training on the physical working capacity at the fatigue threshold (PWCFT), timed sit-ups, and the standing long jump. Thirty-three untrained to moderately trained men (mean ± SD; age = 21.6 ± 2.8 years) participated in this double-blind, placebo-controlled study and were randomly assigned to either a CLA (Clarinol A-80; n = 17) or placebo (PLA; sunflower oil; n = 16) group. Before and after 6 weeks of aerobic training (50% V[Combining Dot Above]O2peak for 30 minutes, twice per week) and supplementation (8 ml CLA or PLA per day), each subject completed an incremental cycle ergometer test to exhaustion to determine the PWCFT, maximal number of sit-ups in 1 minute, and the standing long jump. There were no differences (all p ≥ 0.23) between the CLA and PLA groups for the analysis of covariance–adjusted posttest mean values for PWCFT, sit-ups, or standing long jump. The PWCFT increased from pre- to posttraining in the CLA (p = 0.003) and PLA (p = 0.003) groups. There were no differences (p > 0.05) from pre- to posttraining for sit-ups and standing long jump in either the CLA or PLA groups. There was no effect of CLA on the training-induced increases in PWCFT, nor were there any effects of CLA or aerobic training on the maximum number of sit-ups or standing long jump. Thus, CLA had no ergogenic benefits on this model of aerobic training–induced improvements in neuromuscular fatigue, or on field tests of muscle endurance and power.

Motor unit control strategies of endurance- versus resistance-trained individuals

Introduction: We examined motor unit (MU) control properties of resistance‐trained (RT) and endurance‐trained (ET) individuals. Methods: Five RT (age 25u2009±u20094 years) and 5 ET (age 19u2009±u20091 years) subjects participated. Surface electromyography (EMG) data were recorded from the vastus lateralis during isometric trapezoid muscle actions at 40% and 70% of maximal voluntary contraction. Decomposition and wavelet transform techniques were applied to the EMG signals to extract the firing events of single MUs and EMG intensity across the frequency spectrum. Results: There were significant differences between RT and ET for the mean MU firing rate and derecruitment threshold versus recruitment threshold relationships and EMG intensity at various wavelet bands during the linearly increasing, steady force, and linearly decreasing segments of the trapezoid contraction. Conclusions: MU behavior is altered as a function of training status and is likely the result of differences in the physical properties of the MU. Muscle Nerve 52: 832–843, 2015

A prospective report on the prevalence of heart rate and blood pressure abnormalities in veterans with spinal cord injuries.

Abstract Objective Decentralized autonomic cardiovascular regulation may lead to increased prevalence of heart rate (HR) and blood pressure (BP) abnormalities in veterans with SCI. In addition, comorbid medical conditions and prescription medication use may increase HR and BP abnormalities. These abnormalities include bradycardia, and tachycardia, hypotension, hypertension as well as autonomic dysreflexia and orthostatic hypotension; the prevalence of which is unknown. Design HR and BP data were measured during a routine annual physical examination in 64 veterans with SCI. Measurements of HR and BP were recorded in the seated and supine positions to document the influence of body position and to document intra-subject variability in these assessments. Results All subjects were chronically injured (20 ± 14 years), 33 subjects were tetraplegic (T: C3–C8), nine had high paraplegia (HP: T1–T6), and 22 had low paraplegia (LP: T7–L2). Regardless of position, the prevalence of bradycardia was increased in the T group, whereas prevalence of tachycardia was increased in the HP and LP groups. Systolic hypotension was more common in the T and HP groups than the LP group and positional effects were most evident in the T group. Systolic hypertension was comparable in the T and HP groups but was twice as prevalent in the LP group. Increased prevalence of individuals with three or more medical conditions and prescribed three or more medications which might influence HR and BP was observed. Conclusion Decentralized autonomic regulation, comorbid medical conditions, and prescription medication use in veterans with SCI result in HR and BP abnormalities; our data suggest that these abnormalities vary depending on the level of injury and orthostatic positioning.

Quantifying the effects of electrode distance from the innervation zone on the electromyographic amplitude versus torque relationships.

The present study applied a log-transformation model to compare the electromyographic (EMG) amplitude versus torque relationships from monopolar EMG signals up to 35 mm proximal and distal from the innervation zone (IZ). Seven men (age = 23 ± 2 year; mass = 82 ± 10 kg) and two women (age = 21 ± 1 year; mass = 62 ± 8 kg) performed isometric ramp contractions of the right leg extensors with an eight-channel linear electrode array positioned over the vastus lateralis with the IZ located between channels 4 and 5. Linear regression models were fit to the log-transformed monopolar EMG(RMS)-torque relationships with the b terms (slope) and the a terms (Y-intercept) calculated for each channel and subject. The b terms for channels 4, 5, and 6 were higher (P ≤ 0.05) than the more distal channels 7 and 8 (P < 0.05). In contrast, there were no differences (P > 0.05) among the a terms of the eight channels. Thus, the shapes of the monopolar EMG(RMS)-torque relationships were altered as a function of distance between the IZ and recording area, which may be helpful for clinicians and researchers who infer changes in motor control strategies based on the shapes of the EMG(RMS)-torque relationships.

Hemodynamic Effects of l-Threo-3,4-Dihydroxyphenylserine (Droxidopa) in Hypotensive Individuals With Spinal Cord Injury

OBJECTIVESnTo determine the effect of an escalating dose of droxidopa (100, 200, and 400 mg) compared with placebo on seated blood pressure (BP) in hypotensive individuals with spinal cord injury (SCI). Secondarily, we aimed to determine the effect of droxidopa on (1) supine BP and heart rate, (2) the change in BP and heart rate when these individuals were transferred from the supine to the seated position, and (3) adverse event (AE) reporting.nnnDESIGNnOpen-label dose titration trial.nnnSETTINGnA Veterans Administration Medical Center.nnnPARTICIPANTSnParticipants with SCI (C3-T12) (N=10) were studied during 4 laboratory visits. Subjects visited the laboratory for about 5 hours on each visit, which incorporated a 30-minute seated baseline, a 30- to 60-minute supine, and a 4-hour seated postdrug observation.nnnINTERVENTIONSnPlacebo on visit 1, droxidopa 100 mg on visit 2, droxidopa 200 mg on visit 3, and droxidopa 400 mg on visit 4.nnnMAIN OUTCOME MEASURESnBP and heart rate changes from baseline to the postdrug period, orthostatic heart rate and BP responses, and subjective AE reporting.nnnRESULTSnSeated BP was significantly elevated with 400 mg droxidopa compared with placebo and 100 mg droxidopa for 3 hours and was elevated for 2 hours compared with 200 mg droxidopa. Increase in supine BP was not worsened following droxidopa, and the expected fall in BP when transferred to the seated position was prevented with droxidopa 200 and 400 mg. There were no significant differences in the heart rate response or AE reporting among the study visits.nnnCONCLUSIONSnOur preliminary findings suggest that droxidopa, at the doses tested, does not cause excessive increases in supine BP and the 400-mg dose appears to be effective at increasing seated BP for up to 3 hours in persons with SCI.

Reminder: RMSSD and SD1 are Identical Heart Rate Variability Metrics.

Assessment of heart rate variability (HRV) is a common approach to examine cardiac autonomic nervous system modulation that has been employed in a variety of settings. Frequently, both the root mean square of successive differences (RMSSD) and SD1, which is a Poincaré plot component, have been used to quantify short‐term heart rate variability. It is not typically appreciated, however, that RMSSD and SD1 are identical metrics of HRV. As a reminder to clinicians and researchers who use and study HRV, we show both empirically and mathematically that RMSSD and SD1 are identical metrics. Because the homology between RMSSD and SD1 is not commonly known, the inclusion of both measures has been reported in many recent publications. The inappropriate use of such redundant data may affect the interpretation of HRV studies. Muscle Nerve 56: 674–678, 2017

CLA Supplementation and Aerobic Exercise Lower Blood Triacylglycerol, but Have No Effect on Peak Oxygen Uptake or Cardiorespiratory Fatigue Thresholds

This study examined the effects of 6xa0weeks of conjugated linoleic acid (CLA) supplementation and moderate aerobic exercise on peak oxygen uptake (

Effects of the innervation zone on the time and frequency domain parameters of the surface electromyographic signal

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