Short-Term Effects of a Ready-to-Drink Pre-Workout Beverage on Exercise Performance and Recovery

Abstract

In a double-blind, randomized and crossover manner, 25 resistance-trained participants ingested a placebo (PLA) beverage containing 12 g of dextrose and a beverage (RTD) containing caffeine (200 mg), β-alanine (2.1 g), arginine nitrate (1.3 g), niacin (65 mg), folic acid (325 mcg), and Vitamin B12 (45 mcg) for 7-days, separated by a 7-10-day. On day 1 and 6, participants donated a fasting blood sample and completed a side-effects questionnaire (SEQ), hemodynamic challenge test, 1-RM and muscular endurance tests (3 × 10 repetitions at 70% of 1-RM with the last set to failure on the bench press (BP) and leg press (LP)) followed by ingesting the assigned beverage. After 15 min, participants repeated the hemodynamic test, 1-RM tests, and performed a repetition to fatigue (RtF) test at 70% of 1-RM, followed by completing the SEQ. On day 2 and 7, participants donated a fasting blood sample, completed the SEQ, ingested the assigned beverage, rested 30 min, and performed a 4 km cycling time-trial (TT). Data were analyzed by univariate, multivariate, and repeated measures general linear models (GLM), adjusted for gender and relative caffeine intake. Data are presented as mean change (95% CI). An overall multivariate time × treatment interaction was observed on strength performance variables (p = 0.01). Acute RTD ingestion better maintained LP 1-RM (PLA: -0.285 (-0.49, -0.08); RTD: 0.23 (-0.50, 0.18) kg/kg_FFM, p = 0.30); increased LP RtF (PLA: -2.60 (-6.8, 1.6); RTD: 4.00 (-0.2, 8.2) repetitions, p = 0.031); increased BP lifting volume (PLA: 0.001 (-0.13, 0.16); RTD: 0.03 (0.02, 0.04) kg/kg_FFM, p = 0.007); and, increased total lifting volume (PLA: -13.12 (-36.9, 10.5); RTD: 21.06 (-2.7, 44.8) kg/kg_FFM, p = 0.046). Short-term RTD ingestion maintained baseline LP 1-RM (PLA: -0.412 (-0.08, -0.07); RTD: 0.16 (-0.50, 0.18) kg/kg_FFM, p = 0.30); LP RtF (PLA: 0.12 (-3.0, 3.2); RTD: 3.6 (0.5, 6.7) repetitions, p = 0.116); and, LP lifting volume (PLA: 3.64 (-8.8, 16.1); RTD: 16.25 (3.8, 28.7) kg/kg_FFM, p = 0.157) to a greater degree than PLA. No significant differences were observed between treatments in cycling TT performance, hemodynamic assessment, fasting blood panels, or self-reported side effects.

Keywords: dietary supplement; ergogenic aid; resistance training; sport nutrition.

Figure 1

Protocol Overview.

Figure 2

Data present mean change (95% CI) in bench press (Panel A) and leg press (Panel B) one repetition maximum (1-RM) from baseline. Confidence intervals not crossing zero are statistically significant (p < 0.05). * Represents p < 0.05 difference from baseline, † represents p < 0.05 difference between treatments. ‡ Represents p < 0.05 to 0.10 tendency towards significance between treatments.

Figure 3

Data present mean change (95% CI) in bench press (A); and leg press (B) muscular endurance repetitions to failure at 70% of one repetition maximum (1-RM) from baseline. Confidence intervals not crossing zero are statistically significant (p < 0.05). * Represents p < 0.05 difference from baseline, † represents p < 0.05 difference between treatments. ‡ Represents p > 0.05 to 0.10 tendency towards significance between treatments.

Figure 4

Data present mean change (95% CI) in bench press (A); leg press (B) and total (combined) lifting volume; (C) from baseline. Confidence intervals not crossing zero are statistically significant (p < 0.05). * Represents p < 0.05 difference from baseline, † represents p < 0.05 difference between treatments. ‡ Represents p > 0.05 to 0.10 tendency towards significance between treatments.

Figure 5

Data present mean change (95% CI) in 4 km time-trial performance from baseline expressed in completion time and absolute power output (A); and relative power output (B). Confidence intervals not crossing zero are statistically significant (p < 0.05). * represents p < 0.05 difference from baseline.