Effects of Acute Preworkout Supplement Ingestion on Hemodynamic Responses, Cognitive Function, and Exercise Performance in Resistance‐Trained Males
Authors: Koozehchian Majid S. , Hosseini Seyyed Vahid , Eynavi Hafez , Mabrey Gina , Owlia Gholamali , Chandler Jeff 
Published: April 2020

PURPOSE

The use of multi‐ingredient preworkout supplements (PWS) has been shown to increase among athletes due to their purported ergogenic benefits. The purpose of this study was to examine the efficacy of acute PWS ingestion to improve hemodynamic responses, cognitive function, and exercise performance in resistance‐trained males.

METHODS

We recruited eight apparently healthy resistance‐trained males with at least six months immediate prior history of resistance training (19±1.1 yr, 173±2.6 cm, 66±2.9 kg, and 13.6±3% body fat) to participate in a randomized, double‐blind, crossover, and placebo‐controlled manner. We instructed participants to maintain their current diet and training regimens throughout the study. Supplements were a 6.5 g maltodextrin placebo (PL) and a commercially available PWS containing 1.6 g beta‐alanine, 1.0 g creatine nitrate, 1.0 g arginine alpha‐ketoglutarate, 321 mg explosive energy blended (including 160 mg caffeine anhydrous, l‐tyrosine, Tea Cor, tetramethyluric acid), 250 mg ascorbic acid, 30 mg niacinamide, 500 mcg vitamin B6, 150 mcg folate, and 20 mcg vitamin B12. In the first and second testing sessions interspersed with a seven‐day washout period, heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP), and visual and auditory reaction time (RT) were measured immediately before and 30 min after ingesting the assigned supplement (i. e., at minutes 10, 20, and 30). Then, the exercise testing protocol was initiated, and strength was assessed as a bench and leg press volume, defined as repetitions to fatigue during set three following two sets of 10 reps at 70% of 1RM for each lifting movement. Additionally, the Wingate test was performed to measure the anaerobic peak and mean power. Repeated‐measures ANOVA, Bonferroni test, and Student’s t‐test were used to analyze data. Results are expressed as mean±SD.

RESULTS

No significant differences were observed in the HR, SBP, and DBP at any point between treatments (p>0.05). There were also no significant differences in the visual and auditory RT at any point between PWS and PL treatments (p>0.05). Nevertheless, a significant improvement was seen in the bench press (PL 1,313±186 kg; PWS 1,463±238 kg, p=0.001), and the leg press performances only in the PWS, not the PL treatment (PL 5,566±616 kg; PWS 6,212±503 kg, p=0.001). Moreover, there was a significant improvement in the Wingate peak power (PL 906±40 Watt; PWS 993±52 Watt, p=0.001) and mean power (PL 473±42 Watt; PWS 510±31 Watt, p=0.001) after ingesting the PWS. The percent changes by ingesting the supplement were 12.62%, 12.66%, 9.61%, and 8.15% for bench press, leg press, peak power, and mean power, respectively.

CONCLUSION

The PWS formula used in this study appears to improve exercise performance, but did not affect hemodynamic responses and cognitive function. It may suggest that a more extended period of study is necessary to determine the potential ergogenic benefits of such a supplement regimen on hemodynamic responses and cognitive function.