ABSTRACT
Products intended to enhance “mental energy” are widely available in the United States, and recently their popularity has increased dramatically. Examples include energy drinks such as Monster® and Red Bull®; energy shots such as 5-Hour Energy™; and a wide variety of dietary supplements such as ginseng and ginkgo biloba (Reissig et al. 2009; Gorby et al. 2010). Other beverages, especially coffee and colas, have long been associated with increased mental energy or related behavioral effects, and their popularity undoubtedly is related to their ability to increase alertness. Over-the-counter caffeine, in pill form, has been available for decades as a performance enhancer. It appears that consumers seek energy beverages and shots to increase their levels of self-perceived energy, and the effects they desire are primarily associated with mental state, not physical energy (Childs 2001; Lieberman 2001, 2006, 2007; O’Connor 2006). Physical energy is a relatively straightforward concept which is well deŠned scientiŠcally. The concept of mental energy is not clearly deŠned and has only recently been the focus of substantial scientiŠc inquiry (Cook and Davis 2006).
