Effects of 8 weeks of Xpand® 2X pre workout supplementation on skeletal muscle hypertrophy,lean body mass,and strength in resistance trained males

Background: xpand® 2x is a proprietary blend comprised of branched chain amino acids,creatine monohydrate,beta-alanine (carnosyn®),quercetin,coenzymated b-vitamins,alanyl-glutamine (sustamine®),and natural nitrate sources from pomegranate and beet root extracts purported to enhance the neuromuscular adaptations of resistance training. however to date,no long-term studies have been conducted with this supplement. the purpose of this study was to investigate the effects of a multi-ingredient performance supplement (mips) on skeletal muscle hypertrophy,lean body mass and lower body strength in resistance-trained males.methods: twenty resistance-trained males (21.3 ± 1.9 years) were randomly assigned to consume a mips or a placebo of equal weight and volume (food-grade orange flavors and sweeteners) in a double-blind manner,30 minutes prior to exercise. all subjects participated in an 8-week,3-day per week,periodized,resistance-training program that was split-focused on multi-joint movements such as leg press,bench press,and bent-over rows. ultrasonography measured muscle thickness of the quadriceps,dual-energy x-ray absorptiometry (dexa) determined lean body mass,and strength of the bench press and leg press were determined at weeks 0,4,and 8 of the study. data were analyzed with a 2 × 3 repeated measures anova with lsd post hoc tests utilized to locate differences.results: there was a significant group-by-time interaction in which the mips supplementation resulted in a significant (p < 0.01) increase in strength of the bench press (18.4% vs. 9.6%) compared with placebo after 4 and 8 weeks of training. there were no significant group by time interactions between mips supplementation nor the placebo in leg press strength (p = .08). mips supplementation also resulted in a significant increase in lean body mass (7.8% vs. 3.6%) and quadriceps muscle thickness (11.8% vs. 4.5%) compared with placebo (group*time,p <0.01).conclusions: these results suggest that this mips can positively augment adaptations in strength,and skeletal muscle hypertrophy in resistance-trained men. © 2013 lowery et al.; licensee biomed central ltd.