Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Feb 1;13(2):167-182.
doi: 10.70252/PHUM1873. eCollection 2020.

Neither a Multi-Ingredient Pre-Workout Supplement nor Caffeine Were Effective at Improving Markers of Blood Flow or Upper-Body Resistance Exercise Performance

Michael S Blake  1 , Nathaniel R Johnson  1 , Kara A Trautman  1 , James W Grier  2 , Sherri N Stastny  1 , Kyle J Hackney  1
Affiliations

Neither a Multi-Ingredient Pre-Workout Supplement nor Caffeine Were Effective at Improving Markers of Blood Flow or Upper-Body Resistance Exercise Performance

Michael S Blake et al. Int J Exerc Sci. .

Abstract

Few studies have measured the effects of multi-ingredient pre-workout supplements on blood flow or heart rate variability or have compared a multi-ingredient pre-workout supplement to a matched single ingredient. This study examined the effects of a multi-ingredient pre-workout supplement, an equivalent amount of caffeine, and placebo on markers of resistance training performance, blood flow, blood pressure, and heart rate variability. The study utilized a randomized, placebo-controlled, repeated-measures, crossover design. Twelve resistance-trained males (22.75 ± 4.51 yrs; 183.4 ± 7.37 cm; 91.05 ± 17.77 kg) completed the study. Resistance exercise performance was defined as total work performed during elbow flexion and extension on an isokinetic dynamometer. Blood flow was calculated using time-averaged mean velocity and blood vessel diameter of the right brachial artery, which were measured via Doppler ultrasound. Heart rate was recorded using an electrocardiogram. Neither a multi-ingredient pre-workout supplement nor caffeine alone improved upper-body resistance exercise performance or markers of blood flow relative to placebo. No differences in heart rate variability were observed across treatments. A multi-ingredient pre-workout supplement was not effective at improving performance or blood flow and did not alter autonomic nervous system function.

Keywords: L-arginine; blood flow; heart rate variability; nitrate; vasodilation.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Mean calculated blood flow of the right brachial artery across different measurement periods. Error bars represent mean ± SD. Blood flow was calculated using TAVM • DIA2 • 0.795. TAVM and DIA were measured via Doppler ultrasound. PRE = multi-ingredient pre-workout supplement. CAF = caffeine supplement. PLA = placebo. Base = baseline. +30 = 30 minutes post supplementation. PostEx = immediately post exercise. +60 = 60 minutes post supplementation.
Figure 2
Figure 2
Performance across time for the three different supplements. Performance was accessed using total work (J) performed during elbow flexion and extension on a Biodex IV Dynamometer for 5 sets of 10 reps at 40% peak isometric force. Error bars represent mean ± SD. PRE = multi-ingredient pre-workout supplement. CAF = caffeine supplement. PLA = placebo.
See this image and copyright information in PMC

References

    1. Anselme F, Collomp K, Mercier B, Ahmaidi S, Prefaut C. Caffeine increases maximal anaerobic power and blood lactate concentration. Eur J Appl Physiol Occup Physiol. 1992;65(2):188–91. - PubMed
    1. Astorino TA, Roberson DW. Efficacy of acute caffeine ingestion for short-term high-intensity exercise performance: A systematic review. J Strength Cond Res. 2010;24(1):257–65. - PubMed
    1. Astorino TA, Terzi MN, Roberson DW, Burnett TR. Effect of two doses of caffeine on muscular function during isokinetic exercise. Med Sci Sport Exerc. 2010;42(12):2205–10. - PubMed
    1. Bailey SJ, Fulford J, Vanhatalo A, Winyard PG, Blackwell JR, DiMenna FJ, et al. Dietary nitrate supplementation enhances muscle contractile efficiency during knee-extensor exercise in humans. J Appl Physiol. 2010;109(1):135–48. - PubMed
    1. Bailey SJ, Winyard P, Vanhatalo A, Blackwell JR, DiMenna FJ, Wilkerson DP, et al. Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans. J Appl Physiol. 2009;107(4):1144–55. - PubMed

LinkOut - more resources