Caffeine and Creatine Use in Sport

Abstract

Background/Aims: Caffeine and creatine are 2 of the most widely available and used compounds in sport. Although the use of either is not considered a doping infraction, the evidence does suggest ergogenic potential in certain sports. The purpose of this paper is to review the pharmacology and potential mechanism(s) of action of caffeine and creatine as they pertain to possible use as an ergogenic aid in sport. Methods: Previous review articles on caffeine and creatine use in sport were screened for relevant information and references, and studies for review and recent articles (2007 onwards) were obtained and reviewed using a PUBMED search with the terms ‘caffeine AND exercise’, ‘creatine and creatine monohydrate AND exercise’, and appropriate linked articles were evaluated. Results: Caffeine taken before (3–6 mg/kg) or during (1–2 mg/kg) endurance exercise enhances performance, through central nervous system and direct muscle effects. Creatine monohydrate supplementation at higher (approx. 20 g/day × 3–5 days) or lower (approx. 5 g/day × 30 days) doses increases skeletal muscle total and phosphocreatine by 10–20%. Creatine supplementation appears to minimally but significantly enhance high-intensity sport performance and the mass and possibly strength gains made during resistance exercise training over the first few months. Conclusions: Although caffeine and creatine appear to be ergogenic aids, they do so in a sport-specific context and there is no rationale for their simultaneous use in sport. Higher doses of caffeine can be toxic and appear to be ergolytic. There is no rationale for creatine doses in excess of the recommendations, and some athletes can get stomach upset, especially at higher creatine doses.

The effects of different doses of caffeine on performance, rating of perceived exertion and pain perception in teenagers female karate athletes

“…Also, adenosine antagonism in adipocytes clearly leads to increased lipolysis and an increase in plasma free fatty acid (FFA) concentration (Glaister et al, 2014;Tarnopolsky, 2010). Additionally, compared with fast twitch fibers, caffeine may have a greater sensitivity for affecting slow twitch muscle fibers and slow twitch sarcoplasmic reticulum (Davis, Green, 2009).…”

“…Additionally, compared with fast twitch fibers, caffeine may have a greater sensitivity for affecting slow twitch muscle fibers and slow twitch sarcoplasmic reticulum (Davis, Green, 2009). Caffeine increase intracellular cyclic adenosine monophosphate (c-AMP) by phosphodiesterase inhibition (Tarnopolsky, 2010). Increase in c-AMP would lead to a greater lipolysis, and relationship with regulation of adipose tissue (Davis, Grenn, 2009).…”

“…Caffeine by facilitate neuromuscular function at the level of the sarcoplasmic reticulum via release calcium (Ca) on sarcoplasmic reticulum (Davis, Green, 2009;Machado et al, 2010) and caffeine's direct antagonism of adenosine receptors (widely present in human tissue including the brain, skeletal muscle and adipose tissue) (Tarnopolsky, 2010) on the skeletal muscle membrane to enhance excitation-contraction coupling via a greater release of Ca from the sarcoplasmic reticulum and or facilitating Na/k ATPase pump activity (Hendrix et al, 2010). Also, adenosine antagonism in adipocytes clearly leads to increased lipolysis and an increase in plasma free fatty acid (FFA) concentration (Glaister et al, 2014;Tarnopolsky, 2010).…”

An Update on Effects of Creatine Supplementation on Performance: A Review

“…This system acts as a temporal energy buffer, providing the majority of energy for the first 6-8s of muscular work. As PCr stores deplete, and ATP resynthesis diminishes, anaerobic glycolysis becomes the predominant energy source [28]. It has been theorized that the volume of PCr existent within the muscles will significantly influence the amount of energy generated during short periods of high intensity exercise [31,32], with early research by Katz et al [33], stating that fatigue is more closely related to low PCr stores than high lactate content.…”

“…It is also worth noting that once supplementation has ceased, serum CR levels will return to their pre-supplementation level within a 30-day period [22]. Milk (1% Fat) 250 ml/8oz 0.05 Table 1: Creatine content as present in raw food products [28].…”