# Psychophysiological Effects of a Single Dose vs. Partial Dose of Caffeine Gum Supplementation on the Cognitive Performance of Healthy University Students: A Placebo Controlled Study

## TL;DR

This study compares the effects of single and partial doses of caffeine gum on cognitive performance and physiological responses in university students.

## Contribution

The study evaluates the psychophysiological effects of caffeine gum in a dual-task setting, comparing single and partial doses.

## Key findings

- Single dose of caffeine gum improved Stroop test performance compared to partial and placebo doses.
- Single dose showed favorable effects on heart rate and perceived exertion ratios.
- No significant changes in reaction time were observed across conditions.

## Abstract

Background: Caffeine has become the psychostimulant with the highest use worldwide by different segments of the population. This is mainly due to the wide variety of benefits it offers in different contexts of use. It is available in various forms, with caffeine chewing gum recently generating great interest due to its characteristics and absorption time. Methods: A placebo-controlled study was conducted in which 20 healthy university students were exposed to three different conditions (single dose, partial dose, and placebo). The intervention consisted of a dual task in which heart rate, perceived exertion, and reaction time were monitored using the Stroop test and choice reaction time test while participants performed two blocks of cycloergometer exercise. Results: A t-test comparison between blocks showed differences in the Stroop test under all conditions, with the single dose having the best performance (Gr.A p < 0.001; Gr.B p < 0.029; Gr.C p < 0.009). The single dose group also showed favorable results for the HR/RPE ratio (p < 0.044) and an increase in the rate of perceived exertion (p < 0.006). No changes in reaction time were observed under any condition of the choice reaction time test. Conclusions: These results suggest that caffeine supplementation has positive effects on variables related to psychophysiological performance during a dual task. A single dose showed the best results in this study; however, longer intervention designs could be considered in the future to see the effect of partial doses of caffeine over time.