Acute Effects Of A Multi-ingredient Pre-workout Supplement On 5-km Running Performance In Recreationally-trained Athletes

Abstract

PURPOSE: The purpose of the present study was to examine the effects of an acute dose of a multi-ingredient, thermogenic, pre-workout supplement on 5-km running performance and subjective measures of fatigue. METHODS: Twenty aerobically-trained, college-aged males (n = 10, mean ± SD = 80.8 ± 6.1 kg) and females (n = 10, 64.5 ± 6.6 kg) completed two 5-km running races for time. During the first session, the subjects were randomly assigned to ingest the supplement or placebo 30 minutes prior to running a 5-km race as fast as possible. The supplement contained multiple ingredients including caffeine anhydrous (150 mg), beta alanine (1.6 g), arginine AKG (1.0 g), as well as tyrosine, L-carnitine, green coffee bean extract, and velvet bean extract at unspecified quantities. The placebo was a non-caloric mix that was matched for flavor and consistency. Subjects also completed a 5-point Likert scale (1 = low, 5 = high) questionnaire to determine feelings of fatigue immediately prior to ingesting the substance (baseline), 30 minutes post-ingestion (immediately pre-race), and 5 minutes post-race. For the second session, subjects ingested the opposite substance (supplement or placebo) and underwent the same testing procedures (including time of day) as the first session. Race times were compared between the supplement and placebo conditions using a paired-samples t-test. In addition, a two-way ANOVA with repeated measures was used to compare the feelings of fatigue among the conditions (supplement vs. placebo) at the common time points (baseline, pre-race, post-race). RESULTS: The results indicated there was no significant (P > 0.05) difference in 5-km race time between the supplement (23.62 ± 2.08 min) and placebo (23.51 ± 1.97 min) conditions. For the feelings of fatigue, there was no significant condition x time interaction or main effect for condition, but there was a main effect for time. Specifically, the marginal means (collapsed across conditions) for fatigue were significantly (P < 0.05) greater post-race (3.3 ± 0.8) than at baseline (2.3 ± 0.7) and pre-race (2.4 ± 0.6). CONCLUSIONS: The findings of the present investigation indicated that the pre-workout supplement provided no ergogenic effect on 5-km race time or feelings of fatigue when administered on an acute basis in recreationally-active males and females.