PHOTO: ALEKSANDR MARKIN
WENDY SWEET
Time for an energy boost? Caffeine might not be the answer.
Teachers Matter
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or a substance that is naturally produced by plants as a pesticide toward insects, caffeine has certainly found its place in society. Consumption of coffee and energy drinks is on the rise. With the interest in caffeine as an energy booster, there is also an interest in caffeine as an ergogenic potential in sports performance. It’s an accepted ergogenic aid by the International Olympic Committee and athletes have used it for years to enhance performance. So with winter sports already in full flight, it seems timely to remind PE teachers and coaches of not only its mechanisms in exercise performance but also its risks. Caffeine as a performance aid Caffeine enhances endurance performance. It very simply stimulates the central nervous system (CNS) and in technical terms acts as
an adenosine-receptor antagonist throughout the body. Although studies are not entirely clear on the exact mechanism of caffeine as an ergogenic aid, the general consensus is that caffeine stimulates a number of different actions and re-actions at the cellular level. The intake of caffeine triggers an increase in blood circulation, heart rate, urine output, gastric secretions and causes a decrease in glucose metabolism. How does all this happen? Well, as caffeine is metabolised in the liver, it stimulates the release of the adrenal hormone, adrenaline, into the blood-stream. Adrenaline (or epinephrine), helps to “un-lock” fat stored in adipose tissue and/or skeletal muscle, releasing these stored triglycerides out to the general circulation. This process is known as “lipolysis.” Subsequent break-down of these triglycerides means that Free Fatty Acid (FFA) levels are increased in the circulation. These circulating
FFA’s become available as a source for energy production in the early phase of exercise, thus “sparing” the use of glycogen stored in muscles. This “glycogen-sparing” effect of caffeine is critical in sports performance as it helps delay the early onset of fatigue. In endurance-related cardiovascular activities of 30 to 60 minutes, caffeine intake may well reduce the need to use muscle carbohydrate (glycogen). Its effects haven’t been replicated in short-term, high-intensity exercise or in recreational athletes, especially females. On a further note, taking caffeine pills to support weight loss has not been confirmed in any research studies. Most interestingly for athletes, though, is the research identifying caffeine as having analgesic properties. In the context of sports and exercise, it may help to ameliorate pain. Although this isn’t a good thing to
