Coffee not only helps us get out of bed and function in the morning, it can also help us exercise. New research suggests that drinking coffee prior to a workout can enhance performance, particularly in sports activities where endurance plays a major role, such as running and cycling.
In a small study conducted at CoventryUniversity, scientists believe they have discovered a solid explanation for why caffeine may be beneficial for exercising, as participants who drank a caffeinated beverage were able to work out much longer than those who drank a caffeine-free version of the same beverage.
The findings showed that caffeine seems to impart a physiological as well as a psychological benefit, evidenced by the fact that exhaustion was significantly delayed and participants displayed more eagerness and motivation to continue the activity.
Although the exact mechanism of action is not completely understood, Michael Duncan, a senior lecturer in sports science at the Universityof Exeterin Englandand lead author of the study, believes that caffeine hinders the accumulation of adenosine within muscles during exercise.
Adenosine is a bodily substance that blunts the force of muscle contractions. This means that a reduction in the quantity of this chemical in muscles will enable them to contract more forcefully, thus delaying fatigue.
Aside from adenosine reduction, other mechanisms may be factors as well. A study published in the Journal of Applied Physiology found that participants in team sports performed 16 percent better if they had consumed caffeine beforehand. Scientists found the caffeine seemed to lower the buildup of potassium in the fluid between muscles. Researchers explained that the accumulation of potassium can cause fatigue during anaerobic activity, such as team sports.
In addition to caffeine’s fatigue-delaying effect on muscles, it also influences the central nervous system, enhancing mood, alertness and fine motor coordination during activity. Another recent study found that sports players displayed greater accuracy if they had taken caffeine prior to their game.
A Word of Caution
An expert cautions that the precise dose of caffeine needed to enhance exercise performance has yet to be determined and the drug has adverse side effects, such as nervousness, high blood pressure and restlessness, along with increased heart rate and irritability.
Other significant effects include diuresis, which can lead to dehydration, and insomnia, which is detrimental to health. The MayoClinic cautions that overdosing on caffeine can have serious effects, such as delirium and convulsions. Moderation is essential for healthy caffeine consumption.
While further research is needed, most people can benefit from the positive effects resulting from drinking a cup of coffee before working out.
 Duncan MJ et al. The acute effect of a caffeine containing energy drink on mood state, readiness to invest effort and resistance exercise to failure. J Strength Cond Res. 2011 Nov 23. [Epub ahead of print.]
 Mohr M, Nielsen JJ and Bangsbo J. Caffeine intake improves intense intermittent exercise performance and reduces muscle interstitial potassium accumulation. J Appl Physiol. 2011 Nov;111(5):1372-9.