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Wired to Win? - Use of Caffeinated Drinks
Alex M. McDonald, MD

Many athletes use caffeine before and during competition with the goal to boost physical performance. Energy Drinks, coffee
and other products claiming to pack a punch are heavily marketed toward athletes and non-athletes as performance
enhancers. Often these ads and promotions are linked to athletics and extreme sports. As mentioned previously, many of
these products are advertised as able to increase endurance, reaction time and concentration. Although energy drinks claim
the benefit is due to various herbs and substances, any physical or mental effects are most likely due to the caffeine content.
Which begs the question, does caffeine promote athletic performance, particularly endurance athletics?
First off it should be mentioned that caffeine is a drug, not unlike many other controlled substances, and there is potential for
serious health consequences with abuse. Significant sources of caffeine include coffee (12-25mg/oz), tea (0-5mg/oz), cola
drinks (4-8mg/oz), energy drinks (12-26mg/oz) and chocolate (variable levels). The most notable behavioral effects of
caffeine occur after consumption of low to moderate doses (50-300 mg) and include increased alertness, energy, and ability
to concentrate. Moderate caffeine consumption rarely leads to health risks. In contrast, higher doses of caffeine induce
negative effects such as anxiety, restlessness, insomnia, and tachycardia. These effects are seen primarily in a small group
of individuals who are caffeine sensitive. On the other hand, caffeine was considered in one study as a potential drug of
abuse and more recently was described as a "model drug of abuse."
Research has found that consumption of moderate levels of caffeine prior to and during exercise is safe and effective. Most
studies have found that consuming 3-6 mg of caffeine per kg of body mass has the optimal effect to enhance athletic
performance. Consuming more than this level does not seem to result is greater benefit, and may in fact increase the risk of
negative side effects. Caffeine's exact effect on the physiologic machinery is not exactly known, however, it is believed to
act in the brain and possibly on muscles at a cellular level.
There are potential negative effects of caffeine consumption on athletic performance. Caffeine can result in side effects such
as heart-burn, gastric reflux, or simply an upset stomach. Caffeine, especially if consumed in the late afternoon or evening
can result in sleep disturbance and insufficient recovery. Lastly, caffeine and other substances in coffee, chocolate and tea
can interact with other dietary supplements and inhibit the body's ability to absorb certain vitamins and minerals, so vitamins
and caffeine should not be consumed together.
Regular caffeine consumption may cause tolerance or dependence, and abrupt discontinuation may cause irritability, mood
shifts, headache, drowsiness, or fatigue. Often these symptoms are not prolonged and diminish or resolve after a relatively
short period of time. However, this can have an affect on the amount of caffeine required to produce benefit during
athletics. As the body is more accustom to the presence of caffeine, a higher level is required to produce a physiologic
benefit. As a result, many studies suggest a caffeine taper, of 3-7 days, prior to an athletic event. As a result the caffeine
consumption on race day will probably have a greater impact.
There have been limited studies to examine the effect of hydration and electrolytes with respect to caffeine, which can play a
critical factor in endurance and ultra-endurance events. The results of this research are mixed with little evidence to
support that caffeine results in dehydration. However, caffeine has been shown to have a diuretic effect (increase loss of
body water through increased urination). However, the addition of moderate levels of caffeine to a standard sports drink or
while consumed with other forms of electrolytes does not seem to have a negative impact on hydration and athletic
performance. However, the hydration effects of larger quantities of caffeine, such as that found in energy drinks, are not
known and should be avoided during athletics. Additionally, the high sugar content in energy drinks may cause GI problems.
Caffeine is a powerful stimulant and can boost athletic performance when consumed in low to moderate levels. I find a mug of 53x11 coffee (, or caffeinated PowerGels ( will give many athletes the boost they need before a workout, race or as a pick me up during the day.


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