Caffeine and carbohydrate are known to independently improve certain aspects of athletic performance. However, less is understood about physiological and performance outcomes when these compounds are coingested in a rehydration and carbohydrate-replacement strategy.
A number of studies have convincingly demonstrated that ingesting compounds and solutions containing caffeine provides an ergogenic benefit to performance during prolonged exercise. There is also recent evidence that these performance benefits may be extended to intermittent high-intensity team sports.
Carbohydrate – (CHO) and fluid-replacement strategies are central to maintaining performance throughout exercise in field sports such as soccer. In addition to replenishing CHO and fluid, caffeine has potential to further enhance human performance when ingested in the correct dose. Integrating caffeine with existing fluid- and fuel-replacement strategies may provide an effective and practical supplementation regimen during training and competition. Supporting this suggestion are findings that show that caffeine, when coingested with a sports drink, provides an ergogenic benefit greater than that afforded by the CHO, fluid, or electrolyte components alone.
Furthermore, the magnitude of performance enhancement when caffeine is coingested with CHO appears comparable to that seen only with larger doses of caffeine alone.
Several studies have specifically examined the influence of caffeinated CHO solutions on high-intensity exercise performance. Maximal strength after 135 min of cycling appeared to be better maintained by the addition of 195 mg/L caffeine to a 6% CHO solution. Similarly, maximal cycling power and voluntary force production during 120 min of cycling have been shown to improve when 6 mg/kg body mass of caffeine is added to a 6% CHO solution.
The performance improvements observed during these studies were largely attributed to caffeine’s influence on the central nervous system, without any detectable alterations in substrate utilization occurring during exercise.
The modification of perceptual responses, particularly perceived effort sense, is consistent with the known actions of caffeine and may account for a large component of the ergogenic effects of caffeinated CHO drinks. Nevertheless, it is also possible that the combination of caffeine and CHO affords some metabolic benefit to exercise above that of caffeine alone. Recently caffeine has been shown to increase exogenous CHO oxidation rate during exercise and may also increase rates of glycogen resynthesis during recovery from exercise.
Despite the mounting evidence regarding the ergogenicity of caffeinated CHO solutions, there remains a dearth of knowledge concerning the outcome of caffeine ingestion on motor-skill performance and other more specific measures of athletic ability that are central to success in team sports such as soccer. Caffeine ingestion alone has been shown to enhance soccer passing skill, and CHO ingestion is known to offset the decline in soccer skill and sprinting performance that occurs during prolonged match play.
Given these findings it seems possible that ingesting CHO and caffeine influences soccer skill and high-intensity performance in a cumulative fashion.
I say that, adding a moderate dose of caffeine (3.7 mg/kg body mass) to a 6% CHO electrolyte solution improves sprinting performance and CMJ height and enhances the psychological status of players during 90 min of simulated soccer activity. Athletes’ ratings of pleasure–displeasure (Feeling Scale) is also influenced favorably during exercise by the ingestion of caffeine.
Previous research has shown that CHO ingestion during prolonged soccer activity positively influences the affective states of players compared with energy-free solutions and demonstrate that caffeine may have a further additive effect on this phenomenon. The enjoyment derived from physical activity is a strong intrinsic motivator of athletic performance, and these factors are likely to be important in maintaining self-selected performance during intermittent exercise.
My documentation support the notion that a caffeinated sports drink is as effective as a traditional formulation at maintaining hydration status when ingested before and during prolonged intermittent sports.
The most likely explanation for performance enhancements are altered subjective perceptions of exercise intensity and fatigue. It also appears that this caffeine-ingestion strategy has just a placebo influence on soccerpassing skill or fluid balance.
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