Benefits and Risk Of Caffeine Use

Caffeine is one of the most widely used stimulants by both the general population and sport and fitness athletes. Benefits of caffeine use have been reported to include increased alertness, decreased fatigue, increased energy, decreased rate of perceived exertion, increased reaction times and many more. There are many conflicting studies citing the benefits of caffeine use. Most reports do agree that it has beneficial effects on both the metabolic process and the nervous system (Gonzalez, A., Walsh, A., Ratamess, N., Kang, J., Hoffman, j., 2011).

Moderate doses of caffeine have been shown to have a beneficial effect on performance when taken pre-workout or pre-activity. The means by which caffeine increases performance is still unclear although mounting data suggests causes come from multiple sources and have both metabolic effects and effects on the central nervous system. It has been reported that caffeine taken prior to exercise can spare carbohydrate usage and cause the rate of perceived exertion to be exaggerated and then suppressed as exercise intensity increases. More studies are needed to determine how caffeine provides its pre-exercise/workout benefits (Dean, S., Braakhuis, A., Paton, C., 2009).

Studies also indicate that while moderate doses of caffeine taken prior to exercise can increase performance, doubling the dose provides no additional benefit. It appears that moderate doses of caffeine are more beneficial for performance enhancement than low or large doses (Desbrow, B., Biddulph, C., Devlin, B., Grant, G., Anoopkumar-Dukie, S., Leveritti, M., 2012).

Another reported neural benefit of moderate doses of caffeine is the reduction of muscle pain during exercise. Research does indicate that caffeine may act as an antagonist with adenosine receptors. This may cause a reduction in pain signaling through neurotransmitters as well as other effects on the central nervous system. Again, more research is required to provide definitive answers on the role caffeine plays with the nervous system (Gliottoni, R., Meyers, J., Arngrímsson, S., Broglio, S., Motl, R., 2009).

Caffeine is reported to cause an increase in the amount of neurotransmitters available and has an enhancing impact on motor neurons which may partly explain why performance is increased with moderate doses (Gonzalez, A., Walsh, A., Ratamess, N., Kang, J., Hoffman, j., 2011).

It is generally accepted that low to moderate caffeine intake is safe for healthy adults. One risk factor reported frequently, states that ingesting caffeine prior to activity increases a person’s heart rate. This may be an issue for apparently healthy people who have an unknown heart condition. With this topic, there are also many conflicting reports concerning heart rate elevation. Studies have shown a higher heart rate level exists in people consuming moderate doses of caffeine prior to exercise due to caffeine’s impact on the sympathetic nervous system but no adverse effects have been widely documented (Dean, S., Braakhuis, A., Paton, C., 2009).

References:

Dean, S., Braakhuis, A., Paton, C. (2009). The Effects of EGCG on Fat Oxidation and Endurance Performance in Male Cyclists. International Journal of Sport Nutrition and Exercise Metabolism, 20, 624-644.

Desbrow, B., Biddulph, C., Devlin, B., Grant, G., Anoopkumar-Dukie, S., Leveritti, M. (2012). The effects of different doses of caffeine on endurance cycling time trial performance. Journal of Sports Sciences, 30(2): 115–120.

Gliottoni, R., Meyers, J., Arngrímsson, S., Broglio, S., Motl, R. (2009). Effect of Caffeine on Quadriceps Muscle Pain During Acute Cycling Exercise in Low Versus High Caffeine Consumers. International Journal of Sport Nutrition and Exercise Metabolism, 19, 150-161.

Gonzalez, A., Walsh, A., Ratamess, N., Kang, J., Hoffman, j. (2011). Effect of a pre-workout energy supplement on acute multi-joint resistance exercise. Journal of Sports Science and Medicine 10, 261-266.

Eric Dempsey

NASM Certified Personal Trainer 

& Weight Loss Specialist

Dempsey's Resolution Fitness