Stacie Urbina

Effects of ingestion of a commercially available thermogenic dietary supplement on resting energy expenditure, mood state and cardiovascular measures.

BackgroundIncreasing metabolism is a primary focus of many commercially available dietary supplements marketed to support weight management. Caffeine (e.g. anhydrous and herbal) and green tea are key ingredients in such products, augmenting resting energy expenditure (REE) and improving reported mood states (alertness, fatigue, focus, etc.). The purpose of this study was to evaluate the effects of a thermogenic dietary supplement (DBX) on REE, respiratory exchange ratio (RER), reported measures of alertness, focus, energy, concentration, fatigue, and hunger, as well as the general safety of the product based on electrocardiogram (ECG) and hemodynamic responses in habitual caffeine consumers.MethodsSix male and six female subjects (mean ± SD; 22.50 ± 3.22 years; 76.94 ± 14.78 kg; 22.7 ± 9.5% body fat), physically active (≥12 months), and moderate habitual caffeine consumers (<200 mg/day) received either two capsules of DBX containing 340 mg of total caffeine plus green tea extract, yerba mate extract, carnitine tartrate and other active ingredients or a placebo (PLC) in a double-blinded, crossover design. Heart rate (HR), blood pressure (BP), REE, RER and perceived mood states were measured at baseline and then hourly for four hours after ingesting either treatment.ResultsResting energy expenditure was significantly increased at all four time points and significant increases were determined for perceived alertness (p = 0.026) and focus (p = 0.05) at hour 1 and for energy at 1 and 2 hours after treatment for the DBX group (p = 0.008 and p = 0.017, respectively). Additionally, perceived fatigue was decreased at the hour 1 assessment (p = 0.010). No significant differences were seen between DBX and placebo for hunger, anxiety, HR, BP, ECG patterns or RER.ConclusionsThe results of this investigation support that the proprietary blend of this thermogenic aid is capable of increasing REE for four hours post-ingestion while supporting increased focus, alertness, and energy as well as decreasing fatigue without promoting anxiety or causing significant changes in HR, BP, or ECG measurements in habitual caffeine consumers.

Acute effects of a commercially-available pre-workout supplement on markers of training: a double-blind study.

BackgroundPre-workout supplements containing numerous ingredients claim to increase performance and strength. Product-specific research is important for identifying efficacy of combined ingredients. The purpose of this study was to evaluate the effects of a proprietary pre-workout dietary supplement containing creatine monohydrate, beta-alanine, L-Tarurine, L-Leucine, and caffeine, on anaerobic power, muscular strength, body composition, and mood states.MethodsIn a double-blind, randomized, matched-pair design, twenty male subjects (mean ± SD; 22.4 ± 9.5 yrs, 76.9 ± 11.2 kg, 22.7 ± 9.5% body fat), consumed either 30 g of a pre-workout supplement (SUP) or maltodextrin placebo (PLC) 30 minutes before a resistance training workout, after completing baseline testing. Body composition was determined via dual-energy x-ray absorptiometry (DEXA). Subjects completed 12 vertical jumps for height (VJ) and one repetition maximum (1RM) and repetitions to failure lifts on bench (BPM) and leg press (LPM). Finally, subjects completed a Wingate power test on a cycle ergometer [mean power (WMP) and peak power (WPP)]. After baseline testing, participants completed eight days of supplementation and four split-body resistance-training bouts. Side effect questionnaires were completed daily 30 minutes after consuming the supplement. Subjects completed post-supplement testing on Day 8. Data were analyzed utilizing a 2 × 2 repeated measures ANOVA [treatment (PLC vs SUP) × time (T1 vs T2)] and ninety-five percent confidence intervals.ResultsThere were no significant treatment × time interactions (p > 0.05). There were no significant changes in %body fat (%BF; ∆-0.43 ± 0.58; p = 0.920), fat mass (∆-2.45 ± 5.72; p = 0.988), or lean body mass (LBM; 10.9 ± 12.2; p = 0.848). 95% CI demonstrated significant LBM increases for both groups. There was a main effect for time for WPP (∆100.5 ± 42.7W; p = 0.001), BPM (∆8.0 ± 12.9 lbs; p = 0.001), and LPM (∆80.0 ± 28.8 lbs; p = 0.001), with no significant differences between treatments. There was no significant difference in mood states between groups or over time.ConclusionThe proprietary pre-workout blend combined with eight days of training did not significantly (ANOVA) improve body composition or performance. While not significant, greater gains in LPM were demonstrated in the SUP group for lean body mass and lower body strength. Future studies should evaluate more chronic effects of proprietary pre-workout blends on total training volume and performance outcomes.

Pre- versus post-exercise protein intake has similar effects on muscular adaptations

The purpose of this study was to test the anabolic window theory by investigating muscle strength, hypertrophy, and body composition changes in response to an equal dose of protein consumed either immediately pre- versus post-resistance training (RT) in trained men. Subjects were 21 resistance-trained men (>1 year RT experience) recruited from a university population. After baseline testing, participants were randomly assigned to 1 of 2 experimental groups: a group that consumed a supplement containing 25 g protein and 1 g carbohydrate immediately prior to exercise (PRE-SUPP) (n = 9) or a group that consumed the same supplement immediately post-exercise (POST-SUPP) (n = 12). The RT protocol consisted of three weekly sessions performed on non-consecutive days for 10 weeks. A total-body routine was employed with three sets of 8–12 repetitions for each exercise. Results showed that pre- and post-workout protein consumption had similar effects on all measures studied (p > 0.05). These findings refute the contention of a narrow post-exercise anabolic window to maximize the muscular response and instead lends support to the theory that the interval for protein intake may be as wide as several hours or perhaps more after a training bout depending on when the pre-workout meal was consumed.

Effects of β-alanine on body composition and performance measures in collegiate women

Abstract Outlaw, JJ, Smith-Ryan, AE, Buckley, AL, Urbina, SL, Hayward, S, Wingfield, HL, Campbell, B, Foster, C, Taylor, LW, and Wilborn, CD. Effects of &bgr;-alanine on body composition and performance measures in collegiate women. J Strength Cond Res 30(9): 2627–2637, 2016—The purpose of this study was to evaluate the effects of &bgr;-alanine (BA) supplementation and resistance training on body composition and performance. In a double-blind placebo-controlled design, 16 untrained collegiate females (mean ± SD: 21.0 ± 2.2 years; 64.8 ± 8.5 kg; 164.5 ± 7.0 cm; 30.1 ± 5.1 percent body fat [%BF]) completed 8 weeks of resistance training while consuming either 3.4 g BA or placebo (PL; 5 g maltodextrin) before training sessions. Training consisted of 4 days per week upper- and lower-body exercises. Lean body mass (LBM), fat mass (FM), and %BF were assessed using dual-energy x-ray absorptiometry. Maximal oxygen consumption (V[Combining Dot Above]O2max), aerobic time to exhaustion, Wingate peak power, bench press and leg press 1RM (BPmax; LPmax), and repetitions at 65% (BPreps; LPreps), vertical jump (VJ), and standing broad jump were assessed using standard National Strength and Conditioning Association guidelines. All measurements were taken at baseline (T1), 4 weeks (T2), and 8 weeks (T3). Repeated-measures analysis of variance and 95% confidence intervals were used to determine significance. Body composition (LBM, FM, and %BF) improved over time (p < 0.01) for both groups. Maximal strength and VJ increased significantly from baseline to T3 (p ⩽ 0.05). There was a significant interaction for LPreps (p = 0.040), with only BA group resulting in significantly greater LPreps (p = 0.041) at T2 and T3. Results from this study suggest that 8 weeks, 4 days per week progressive resistance training and BA supplementation may be effective for improving lower-body muscular endurance. &bgr;-alanine had no additive effects on body composition or maximal strength in collegiate women.

Effects of a weight loss supplement on body composition and markers of metabolism in overweight male and female adults

Background Various weight loss supplements are commercially available and are composed of a wide variety of ingredients. Combined with a low calorie diet, some dietary supplements could possibly lead to changes in metabolism and/ or suppression of appetite that could lead to improved body composition. The purpose of this study was to investigate the effects of ingesting a commercially available dietary supplement and its effects on body composition, resting energy expenditure (REE), hunger, and various blood markers in free-living, overweight individuals. Methods

The effects of ß-alanine on body composition and performance measures in collegiate females

Background s-alanine has ergogenic potential based on its relationship with carnosine. Carnosine is rapidly degraded into s-alanine and histidine as soon as it enters the blood. So there is no advantage to using direct carnosine supplementation. Previous studies have demonstrated that taking s-alanine orally is effective at increasing intramuscular carnosine levels. The resistance training athlete may experience a higher training volume. This proposed benefit would increase work capacity and decrease time to fatigue. Therefore, the purpose of this study is to evaluate recreationally active collegiate females, following an 8 week strength training program while consuming either s-alanine (BA) or placebo (PL) for body composition and performance changes. Methods

Effects of ingesting Dyma-Burn Xtreme, a thermogenic dietary supplement on metabolic rate and subjective measures of mood state

Background Many supplements on the market today contain ingredients that claim to increase metabolism and enhance fat loss. Green tea extract and caffeine have well known thermogenic properties. The purpose of this study was to evaluate the effects of proprietary thermogenic dietary supplement Dyma-Burn Xtreme, containing a blend of ingredients including caffeine, green tea extract, raspberry ketones and L-carnitine, on resting energy expenditure and subjective measures of alertness, focus, energy, fatigue, concentration, and hunger. Methods In a double-blind, crossover design 6 male and 6 female subjects (N = 12, 22 ± 9.5 yrs, 171 ± 11.2 cm, 76.9 ± 11.2 kg, 22.7 ± 9.5), consumed either a 2 capsule serving of Dyma-Burn Xtreme (DBX) or placebo (PLC). Subjects arrived at the lab on a 12 hour fast at 8:00am and had a baseline resting energy expenditure (REE), respiratory exchange ratio (RER), and mood state questionnaire assessed. Subjects then consumed either DBX or PLC and REE and RER were assessed in a supine position for 25 minutes, and questionnaire were assessed at 1-hour (1HR), 2-hours (2HR), 3-hours (3HR), and 4-hours (4HR) post consumption. All data was analyzed utilizing a 2X5 ANOVA and one-way ANOVA’s were used in the case of a significant interaction. A Kruskal Wallis one-way analysis of variance was used for all survey data. A significance value of 0.05 was adopted throughout. Results A significant time effect and group x time interaction effect were observed among groups for changes in REE (p > 0.05). Post-hoc analyses revealed REE levels were

The effects of post-exercise whey vs. casein protein ingestion on muscular strength, muscular endurance, and body composition in older women (50-70 years of age)

Background As humans age, there is a measurable loss of muscle mass that occurs. Termed sarcopenia, this condition not only results in a loss of muscle mass, but also results in a loss of muscular strength and endurance (Bales, 2002). Research has shown that resistance training decreases this loss of muscle mass and muscular strength (Doherty, 2003). However, in older populations, little evidence exists in regards to the addition of whey or casein protein and the effects of each when combined with resistance training. Therefore, the purpose of this study was to examine the effects of whey versus casein protein supplementationcombined with resistance training on muscular strength, muscular endurance and body composition in older females.

A Purported Detoxification Supplement Does Not Improve Body Composition, Waist Circumference, Blood Markers, or Gastrointestinal Symptoms in Healthy Adult Females

ABSTRACT Numerous popular “detoxification” supplements claim to promote the removal of harmful compounds from the body, thereby alleviating gastrointestinal symptoms, improving body composition, and enhancing overall health. The present double-blind, randomized, placebo-controlled trial was conducted to examine the effects of a purported detoxification supplement in healthy young adult females. Participants were randomly assigned to consume a multi-ingredient supplement or placebo daily for four weeks. The supplement contained 1,350 mg/serving of a proprietary blend of papaya leaf, cascara sagrada bark, slippery elm bark, peppermint leaf, red raspberry leaf, fenugreek seed, ginger root, and senna leaf. Body composition, waist circumferences, symptoms of gastrointestinal distress, and blood safety markers were evaluated before and after supplementation. Twenty-two participants completed the study, and data were analyzed via two-way mixed ANOVA and t tests. No beneficial or harmful effects of supplementation were found for body composition, waist circumference, gastrointestinal symptoms, or blood markers. These results indicate that consuming a commercially available dietary supplement that purportedly provides detoxification and body composition benefits is apparently safe in healthy young adult females but does not provide any beneficial effects for body composition or gastrointestinal symptoms.

Correction: Pre- versus post-exercise protein intake has similar effects on muscular adaptations

[This corrects the article DOI: 10.7717/peerj.2825.].