The Effect of Creatine Nitrate and Caffeine Individually or Combined on Exercise Performance and Cognitive Function: A Randomized, Crossover, Double-Blind, Placebo-Controlled Trial

Abstract

This study examined the effect of creatine nitrate and caffeine alone and combined on exercise performance and cognitive function in resistance-trained athletes. In a double-blind, randomized crossover trial, twelve resistance-trained male athletes were supplemented with 7 days of creatine nitrate (5 g/day), caffeine (400 mg/day), and a combination of creatine nitrate and caffeine. The study involved twelve resistance-trained male athletes who initially provided a blood sample for comprehensive safety analysis, including tests for key enzymes and a lipid profile, and then performed standardized resistance exercises-bench and leg press at 70% 1RM-and a Wingate anaerobic power test. Cognitive function and cardiovascular responses were also examined forty-five minutes after supplementation. Creatine nitrate and caffeine that were co-ingested significantly enhanced cognitive function, as indicated by improved scores in the Stroop Word-Color Interference test (p = 0.04; effect size = 0.163). Co-ingestion was more effective than caffeine alone in enhancing cognitive performance. In contrast, no significant enhancements in exercise performance were observed. The co-ingestion of creatine nitrate and caffeine improved cognitive function, particularly in cognitive interference tasks, without altering short-term exercise performance. Furthermore, no adverse events were reported. Overall, the co-ingestion of creatine nitrate and caffeine appears to enhance cognition without any reported side effects for up to seven days.

Keywords: caffeine; cognitive function; creatine nitrate; dietary supplements; ergogenic aids; exercise performance; resistance training; sports nutrition.

Figure 1

Diagram depicting the consolidated standards for reporting trials in the study.

Figure 2

Study process overview. Panel (A) illustrates the study’s timeline, detailing the familiarization period followed by four treatment phases, each separated by a washout period of one week. Panel (B) provides a detailed sequence of assessment and intervention activities conducted during each treatment phase.

Figure 3

The mean change (with a 95% confidence interval) in the number of bench press repetitions to failure at 70% of 1RM from the initial measurement. Statistically significant findings (p < 0.05) are indicated by confidence intervals that do not cross zero. * denotes a significant difference (p < 0.05) compared to the baseline. We use the following notation to indicate statistical differences between treatments: (a) a significant difference compared to PL (p = 0.04).

Figure 4

The graph illustrates the mean change (95% CI) from baseline to follow-up for the Stroop test-related treatment. Statistically significant findings (p < 0.05) are indicated by confidence intervals that do not cross zero. * denotes a significant difference (p < 0.05) compared to the baseline. Statistical significance is shown as follows: (a) significant difference compared to CAF (p = 0.04).