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

Abstract

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.

Effects of ingesting a pre-workout dietary supplement with and without synephrine for 8 weeks on training adaptations in resistance-trained males

“…4). However, consistent with findings from Outlaw and colleagues [58], we did not observe a significant improvement in body composition changes in response to training as has previously been reported [56, 69]. This includes when adding 20 mg of synephrine (as Citrus Aurantium) to the formulation.…”

“…However, after 8-weeks of training and supplementation in the present study, all groups observed similar improvements in Stroop Word, Color, and Word-Color counts and no differences were observed in questions related to readiness to perform. These findings are consistent with other studies reporting no overall benefit of PWS supplementation on cognitive function, concentration, and/or perceptions of energy [58, 59] and suggest that the ergogenic value observed may lessen over time. However, it is also possible that since performing the 1 RM and anaerobic sprint capacity tests did not require significant executive or cognitive functioning to perform, there may be benefits on other performance tasks that require more decision making and attention.…”

Dietary Caffeine and Polyphenol Supplementation Enhances Overall Metabolic Rate and Lipid Oxidation at Rest and After a Bout of Sprint Interval Exercise

“…Accompanying this thermogenic response was a 4% decrease in RER, corroborating a 10% increase in FO rate. These results correspond with previous reports of enhanced EE REST and lipid oxidation with caffeinepolyphenol supplementation of various dosage combinations (10,29,32). In fact, Hursel et al (19) conducted a meta-analysis that elucidated the importance of combining caffeine and polyphenol catechins to stimulate a thermogenic response that accompanied an increase in FO.…”

“…Although sympathomimetic substances such as caffeine and polyphenol catechins are known cardiovascular stimulants, especially in nonhabitual users, the dosage administered during this study may have precluded a detectable response. A recent randomized controlled trial examining physiological responses to a thermogenic supplement containing similar caffeine and green tea extract dosages indicated no significant hemodynamic or HR changes compared to a placebo treatment (29). The lack of a significant hemodynamic response to the administered dose may suggest that the experimental combination of caffeine and polyphenols accompanies minimal risk for individuals with cardiovascular contraindications to sympathomimetic use at least during rest.…”

Current perspectives of caffeinated energy drinks on exercise performance and safety assessment

“…Additionally, the studies described above reported that daily and pre-exercise consumption of EDs or PWSs for up to 10 weeks during training was well tolerated and not associated with any serious adverse effects. 11,33,37,[47][48][49][50][51][52][53][54][55][56] Nevertheless, a few studies have reported that acute ingestion of ES, ED, and/or PWS caused a short-term increase in resting systolic and/or diastolic blood pressure generally in the 2-5 mmHg range. 29,57,58 However, the reported changes were typically less than observed from standing up or light walking, and most studies have found that acute 36,50,58,59 Nutrition and Dietary Supplements downloaded from https://www.dovepress.com/ by 44.224.250.200 on 12-Jul-2020 For personal use only.…”