Supplement synergy: Creatine nitrate paired with caffeine may amplify cognitive benefits

“The co-ingestion of creatine nitrate and caffeine improved cognitive function, particularly in cognitive interference tasks, without altering short-term exercise performance,” the researchers wrote. “Furthermore, no adverse events were reported."

The study, published in the journal Nutrients​, brought together researchers from Jacksonville State University (USA), Islamic Azad University (Iran), Brandon University (Canada) and Qatar University (Doha).

Synergistic supplements for performance​

The use of dietary supplements to enhance sporting performance has been a well-established practice in athletes, with both caffeine and creatine among the most extensively independently studied ingredients demonstrating ergogenic properties.

Studies have shown the significant benefits of caffeine for sporting performance​ through improving maximum strength and muscular endurance through interactions with the central nervous system, whilst increasing heart rate and blood pressure, and enhancing cognitive function.

Creatine has been shown to rapidly replenish adenosine triphosphate (ATP) levels​ during anaerobic exercise, boosting short-term power output to improve strength, sprinting ability and muscle mass.

Yet, there has been limited investigation into their combined use, with findings remaining contradictory. Thus, the present study sought to investigate the effects of caffeine and creatine nitrate supplementation, both together and independently, on intense intermittent exercise performance and mental focus.

Study details​

The researchers recruited 12 resistance-trained male athletes for the double-blind, randomised crossover trial. The seven-day study involved four treatments: creatine nitrate [CN: (4 g creatine; 1 g nitrate), 5 g/d + 0.675 g/d maltodextrin)], caffeine (CAF: 400 mg/d + 5 g/d maltodextrin), a combination of both CN and CAF (CO: 5 g/d creatine nitrate + 400 mg/d caffeine), and a placebo (PL: 5.4 g/d maltodextrin). Bulk Supplements (Henderson, NV, USA) produced the CAF and maltodextrin, and the CN was sourced from APS Distribution, Inc. (Norcross, GA, USA).

Baseline blood samples were obtained from the subjects prior to the intervention, as well as anthropometric, heart rate and blood pressure readings. Supplements were administered 45 minutes prior to experimental testing. Subjects then completed the Stroop Word-Colour test to assess cognitive function, followed by exercise performance assessments which included standardized resistance exercises—bench and leg press at 70% 1RM—and a Wingate anaerobic power test. Cardiovascular measures were obtained following the exercises.

The researchers reported that performance on cognitive tests assessing attention, processing speed and executive function were significantly greater following co-supplementation, however, no significant benefits to exercise performance were noted following co-ingestion.

Co-intake complexities​

Despite that lack of effect shown for exercise performance following caffeine and creatine co-supplementation, the researchers highlighted that the research provides significant evidence to suggest a complex interplay between the two supplements.

They noted that previous studies suggest that caffeine "may diminish the effectiveness of creatine even though some performance benefits are noted with their combined use".

"This underscores the subtle complexities of how supplements interact and the consequential effects on exercise performance," they wrote.

"Furthermore, the enhanced cognitive performance in the CO group could suggest a synergistic effect of creatine when combined with CAF. This hypothesis is supported by research indicating that the co-supplementation of creatine with CAF may amplify cognitive benefits, with changes potentially related to increased activation in the prefrontal cortex, an area of the brain critical for executive functions." 

Source: Nutrients​
doi: 10.3390/nu16060766​ 
"The Effect of Creatine Nitrate and Caffeine Individually or Combined on Exercise Performance and Cognitive Function: A Randomized, Crossover, Double-Blind, Placebo-Controlled Trial"
Authors: G. Mabrey et al.