Kelley G. Hammond

Effect of the dietary supplement Meltdown on catecholamine secretion, markers of lipolysis, and metabolic rate in men and women: a randomized, placebo controlled, cross-over study

BackgroundWe have recently reported that the dietary supplement Meltdown® increases plasma norepinephrine (NE), epinephrine (EPI), glycerol, free fatty acids (FFA), and metabolic rate in men. However, in that investigation measurements ceased at 90 minutes post ingestion, with values for blood borne variables peaking at this time. It was the purpose of the present investigation to extend the time course of measurement to 6 hours, and to include women within the design to determine if sex differences to treatment exist.MethodsTen men (24 ± 4 yrs) and 10 women (22 ± 2 yrs) ingested Meltdown® or a placebo, using a randomized, cross-over design with one week separating conditions. Blood samples were collected immediately before supplementation and at one hour intervals through 6 hours post ingestion. A standard meal was provided after the hour 3 collection. Samples were assayed for EPI, NE, glycerol, and FFA. Five minute breath samples were collected at each time for measurement of metabolic rate and substrate utilization. Area under the curve (AUC) was calculated. Heart rate and blood pressure were recorded at all times. Data were also analyzed using a 2 (sex) × 2 (condition) × 7 (time) repeated measures analysis of variance, with Tukey post hoc testing.ResultsNo sex × condition interactions were noted for AUC for any variable (p > 0.05). Hence, AUC data are collapsed across men and women. AUC was greater for Meltdown® compared to placebo for EPI (367 ± 58 pg·mL-1·6 hr-1 vs. 183 ± 27 pg·mL-1·6 hr-1; p = 0.01), NE (2345 ± 205 pg·mL-1·6 hr-1 vs. 1659 ± 184 pg·mL-1·6 hr-1; p = 0.02), glycerol (79 ± 8 μg·mL-1·6 hr-1 vs. 59 ± 6 μg·mL-1·6 hr-1; p = 0.03), FFA (2.46 ± 0.64 mmol·L-1·6 hr-1 vs. 1.57 ± 0.42 mmol·L-1·6 hr-1; p = 0.05), and kilocalorie expenditure (439 ± 26 kcal·6 hrs-1 vs. 380 ± 14 kcal·6 hrs-1; p = 0.02). No effect was noted for substrate utilization (p = 0.39). Both systolic and diastolic blood pressure (p < 0.0001; 1–16 mmHg), as well as heart rate (p = 0.01; 1–9 bpm) were higher for Meltdown®. No sex × condition × time interactions were noted for any variable (p > 0.05).ConclusionIngestion of Meltdown® results in an increase in catecholamine secretion, lipolysis, and metabolic rate in young men and women, with a similar response for both sexes. Meltdown® may prove to be an effective intervention strategy for fat loss, assuming individuals are normotensive and their treatment is monitored by a qualified health care professional.

Dietary supplement increases plasma norepinephrine, lipolysis, and metabolic rate in resistance trained men

BackgroundDietary supplements targeting fat loss and increased thermogenesis are prevalent within the sport nutrition/weight loss market. While some isolated ingredients have been reported to be efficacious when used at high dosages, in particular in animal models and/or via intravenous delivery, little objective evidence is available pertaining to the efficacy of a finished product taken by human subjects in oral form. Moreover, many ingredients function as stimulants, leading to increased hemodynamic responses. The purpose of this investigation was to determine the effects of a finished dietary supplement on plasma catecholamine concentration, markers of lipolysis, metabolic rate, and hemodynamics.MethodsTen resistance trained men (age = 27 ± 4 yrs; BMI = 25 ± 3 kg· m-2; body fat = 9 ± 3%; mean ± SD) ingested a dietary supplement (Meltdown®, Vital Pharmaceuticals) or a placebo, in a random order, double blind cross-over design, with one week separating conditions. Fasting blood samples were collected before, and at 30, 60, and 90 minutes post ingestion and were assayed for epinephrine (EPI), norepinephrine (NE), glycerol, and free fatty acids (FFA). Area under the curve (AUC) was calculated for all variables. Gas samples were collected from 30–60 minutes post ingestion for measurement of metabolic rate. Heart rate and blood pressure were recorded at all blood collection times.ResultsAUC was greater for the dietary supplement compared to the placebo for NE (1332 ± 128 pg·mL-1·90 min-1 vs. 1003 ± 133 pg·mL-1·90 min-1; p = 0.03), glycerol (44 ± 3 μg·mL-1·90 min-1 vs. 26 ± 2 μg·mL-1·90 min-1; p < 0.0001), and FFA (1.24 ± 0.17 mmol·L-1·90 min-1 vs. 0.88 ± 0.12 mmol·L-1·90 min-1; p = 0.0003). No difference between conditions was noted for EPI AUC (p > 0.05). For all variables, values were highest at 90 minutes post ingestion. Total kilocalorie expenditure during the 30 minute collection period was 29.6% greater (p = 0.02) for the dietary supplement (35 ± 3 kcal) compared to placebo (27 ± 2 kcal). A condition main effect was noted for systolic blood pressure (p = 0.04), with values increasing from 117 ± 2 mmHg to 123 ± 2 mmHg with the dietary supplement, while remaining unchanged for placebo. No other hemodynamic changes were noted (p > 0.05).ConclusionThe dietary supplement results in an acute increase in plasma NE and markers of lipolysis, as well as metabolic rate. This occurs without altering hemodynamic variables in a clinically significant manner. Intervention studies to determine the impact of this dietary supplement on weight/fat loss are warranted.

Muscle Activation During Various Hamstring Exercises

Abstract McAllister, MJ, Hammond, KG, Schilling, BK, Ferreria, LC, Reed, JP, and Weiss, LW. Muscle activation during various hamstring exercises. J Strength Cond Res 28(6): 1573–1580, 2014—The dorsal muscles of the lower torso and extremities have often been denoted the “posterior chain.” These muscles are used to support the thoracic and lumbar spine and peripheral joints, including the hip, knee, and ankle on the dorsal aspect of the body. This study investigated the relative muscle activity of the hamstring group and selected surrounding musculature during the leg curl, good morning, glute-ham raise, and Romanian deadlift (RDL). Twelve healthy, weight-trained men performed duplicate trials of single repetitions at 85% 1-repetition maximum for each lift in random order, during which surface electromyography and joint angle data were obtained. Repeated measures analysis of variance across the 4 exercises was performed to compare the activity from the erector spinae (ES), gluteus medius (GMed), semitendinosus (ST), biceps femoris (BF), and medial gastrocnemius (MGas). Significant differences (p ⩽ 0.05) were noted in eccentric muscle activity between exercise for the MGas (p < 0.027), ST (p < 0.001), BF (p < 0.001), and ES (p = 0.032), and in concentric muscle activity, for the ES (p < 0.001), BF (p = 0.010), ST (p = 0.009), MGas (p < 0.001), and the GMed (p = 0.018). Bonferroni post hoc analysis revealed significant pairwise differences during eccentric actions for the BF, ST, and MGas. Post hoc analysis also revealed significant pairwise differences during concentric actions for the ES, BF, ST, MGas, and GMed. Each of these showed effect sizes that are large or greater. The main findings of this investigation are that the ST is substantially more active than the BF among all exercises, and hamstring activity was maximized in the RDL and glute-ham raise. Therefore, athletes and coaches who seek to maximize the involvement of the hamstring musculature should consider focusing on the glute-ham raise and RDL.

Structural and functional predictors of drop vertical jump.

Ferreira, LC, Weiss, LW, Hammond, KG, and Schilling, BK. Structural and functional predictors of drop vertical jump. J Strength Cond Res 24(9): 2456-2467, 2010-This investigation was designed to determine if relatively small manipulations of squat load and the inclusion of selected morphologic variables might augment the explained variance in vertical jump (VJ) displacement. Fifty-two university students (27 women and 25 men) with weight training experience served as subjects. All were assessed for body fat percentage (BF%), height, body weight (BW), leg length (LL), ankle range of motion, and quadriceps angle (Q-angle). Additionally, subjects performed drop vertical jumps (DVJs) and both countermovement jump (CMJ) squats and static jump (SJ) squats at 20, 30, and 40% of their back squat 1 repetition maximum (1RM). A preliminary analysis revealed that DVJcm for all subjects (28.1 ± 6.64; mean ± SD) was most highly correlated with both CMJ @ 30% 1RM (CMJ30PP) and SJ @ 20% 1RM (SJ20PP) (r = 0.84, p < 0.001). Forced multiple regression was then used to determine which variables contributed to VJ displacement. The greatest variability explained (83%) used a CMJ: DVJcm = 20.311 + (0.008) (CMJ30PP) − (0.346) (BW). When the same variables were used to calculate separate gender-based regressions, the explained variance in DVJcm (men = 33.0 ± 5.34 cm; women = 23.4 ± 3.79 cm) was 68% for men and 64% for women. These findings suggest that jump squat peak power at a light load is a good predictor of VJ and that its training-induced augmentation would likely improve VJ. The addition of BW to the equation explained slightly more variability in DVJcm than in BF%. Because excess amounts of either would be an additional load to be moved against gravity (fat in general or skeletal muscle in the upper torso), it follows that relatively high levels of either might be expected to attenuate VJ performance.

Effect of Grip Width on Electromyographic Activity During the Upright Row

Abstract McAllister, MJ, Schilling, BK, Hammond, KG, Weiss, LW, and Farney, TM. Effect of grip width on electromyographic activity during the upright row. J Strength Cond Res 27(1): 181–187, 2013—The upright row (URR) is commonly used to develop the deltoid and upper back musculature. However, little information exists concerning muscle recruitment during variations of this exercise. Sixteen weight-trained men completed 2 repetitions each in the URR with 3 grip conditions: 50, 100, and 200% of the biacromial breadth (BAB). The load was the same for all grip conditions and was equal to 85% of the 1RM determined at 100% BAB. Repeated measures analyses of variance were used to compare the maximal activity of the anterior deltoid (AD), lateral deltoid (LD), posterior deltoid (PD), upper trapezius (UT), middle trapezius (MT), and biceps brachii (BB) during the 3 grip widths for eccentric and concentric actions. Significant differences (p < 0.05) were noted in concentric muscle activity for LD (p < 0.001) and PD (p < 0.001), and in eccentric muscle activity for AD (p = 0.023), LD (p < 0.001), UT (p < 0.001), MT (p < 0.001), and BB (p = 0.003). Bonferroni post hoc analysis revealed significant pairwise differences in the concentric actions from the LD (50% vs. 200% BAB and 100% vs. 200% BAB) and PD (50% vs. 200% BAB and 100% vs. 200% BAB), and eccentric actions of the LD (all comparisons), UT (all comparisons), MT (50% vs. 200% BAB and 100% vs. 200% BAB), and BB (50% vs. 200% BAB), with large-to-very-large effect sizes (ESs). Moderate-to-large ESs were noted for several nonsignificant comparisons. The main findings of this investigation are increased deltoid and trapezius activity with increasing grip width, and correspondingly less BB activity. Therefore, those who seek to maximize involvement of the deltoid and trapezius muscles during the URR should use a wide grip.

Reliability of Goniometry-Based Q-Angle

To establish the stability reliability, precision, and minimum value for detecting real differences for quadriceps angle (Q‐angle) measurements based on standardized protocols and surface goniometry.

Acute effects of VPX Meltdown® on plasma catecholamines, free fatty acids, glycerol, metabolic rate, and hemodynamics in young men and women

Background We have recently reported that the dietary supplement Meltdown® (Vital Pharmaceuticals) increases plasma norepinephrine (NE), epinephrine (EPI), glycerol, and free fatty acids (FFA), as well as metabolic rate in healthy men [1]. However, in that investigation measurements ceased at 90 minutes post ingestion, with values for bloodborne variables peaking at this time. It was the purpose of the present investigation to extend the time course of post ingestion measurement to 6 hours.