Discussion
thermogenic beverage formulation, alertness
SECONDARY
The purpose of the present study was to determine the acute effect of an RTD thermogenic beverage formulation on REE, RQ, hemodynamic function, and subjective ratings of energy, focus, concentration, alertness, and mood. The primary findings were that acute consumption of the RTD beverage significantly elevated REE compared to PL without negatively affecting hemodynamic variables. Though REE significantly increased post-ingestion, no statistical interactions were present for RQ, suggesting the increase in REE was due to increases in both carbohydrate and fat oxidation. In addition, the RTD beverage increased subjective measures of energy, focus, concentration, and alertness relative to PL.Multi-ingredient thermogenic products are commonly sought after by individuals aiming to lose body fat and increase energy. These supplements typically contain a blend of active ingredients suggested to increase energy expenditure and promote lipolysis. The RTD beverage employed in the present analysis contained 180 mg per serving of caffeine coming from a blend of caffeine anhydrous, green tea extract, and guarana seed extract (A secondary purpose of this investigation was to determine the impact of a RTD beverage on hemodynamic function. No statistical interactions were present for HR; however, a main effect of condition indicated lower HR in RTD as compared to PL (3.0 ± 0.9 bpm; Finally, in agreement with prior investigations, the RTD beverage influenced subjective outcomes assessed by VAS [A unique characteristic of this study was the strict inclusion/exclusion criteria implemented when recruiting participants. Though limited, prior data demonstrated the potential for training status to affect the metabolic response to caffeine [The present study is not without limitations. Given the strict inclusion/exclusion criteria, the generalizability may be limited to other populations such as endurance-trained individuals or older adults. Therefore, results may differ in populations of a different age, activity level, or health status. In addition, since the current study only included habitual caffeine consumers, the results cannot be extrapolated to non-consumers. Furthermore, we utilized self-reported caffeine intake to determine habitual consumers, which may not be as reliable as more detailed assessment methods. That is, large variability in the caffeine content of commonly consumed beverages have been reported, and as such, an objective measure (e.g. caffeine or metabolite levels) might be more suitable to report caffeine intake [