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Caffeine: Friend or Foe? by Dave Milner 08.01.03Elana Mayer, the South Africa-born women's world record holder for the half-marathon, recently tested positive for a banned performance-enhancing substance. The substance? Not steroids, EPO, or growth hormones, but caffeine. So as I sit here in Bongo Java coffeehouse, slugging my fourth coffee of the day, and contemplating the track workout that is just a few hours away, I pose the rhetorical question: Am I gaining an unfair advantage on my training partners? I certainly hope so!
Don’t expect to run into an espresso machine at an aid station during your next race, but there’s a growing wealth of research indicating caffeine can improve your performance. Athletes in all disciplines of Track & Field have been using caffeine as an ergogenic (performance enhancing) aid for decades. It was one of the first substances to be used as a doping agent and, according to Weight (2003), it remains probably the cheapest and easiest chemical to find and to use.
Indeed, Once thought to be a nutritional no-no for athletes, caffeine has taken center stage in the past few years as a legitimate aid to performance. This benefit has been recognized by the makers of sports nutrition products like energy gels.
But what exactly is caffeine? Caffeine is a mild stimulant that occurs naturally in at least 63 plant species. It is part of the Methylxanthine family.
Sources of caffeine are, by no means, limited to coffee and tea drinks. Various concentrations of caffeine are also found in several types of soft drinks (Coke, Mountain Dew, Mello Yello, etc), energy bars (Clif Bar, Power Bar), and the gel packets commonly used by marathoners (Clif Shot, PowerGel, GU, CarbBoom, etc), or may be found in more concentrated pill-forms (e.g. No-Doze).
Acording to Metcalfe (1999), a number of studies conducted by Dr Terry Graham at University of Guelph, Ontario, have proven caffeine's performance-enhancing power, some yielding 10-15% improvements in endurance, but these studies have been in laboratories, not real-life competitive settings.
Whether, and how, it actually improves performance in the real world is an arguable point. But presumably it does, otherwise it wouldn’t be a substance on the IOC’s banned list, right? Hmmm... well, marijuana is also on the banned list, but we don't see the fleet-footed East Africans tokin' on a fatty prior to their 10Ks, do we?
One reason endurance athletes ingest caffeine is because it increases or accelerates the release of fatty acids from storage in adipose tissue into muscle where it can be used as fuel.
According to Noakes (1991), caffeine ingestion causes free-fatty acid concentrations in the blood to rise, reaching peak values after approximately an hour, but remaining 300-400% higher than normal values for up to 4 hours (Bellet et al., 1968; Weir, et al., 1987). This effect is delayed for the first 2 hours if sugar is taken with the caffeine (as in caffeinated energy gels), but after 4 hours, sugar intake does not affect blood free-fatty acid concentrations.
As there is a plentiful supply of fat in even the leanest of athletes, and a limited stock of carbohydrate, this would certainly seem to improve the situation for those engaging in prolonged periods (1 hour plus) of exercise and at moderate intensities. It is not going to make any real difference in events of shorter duration and higher intensity (a 5K, for example) as the body can burn fat fast enough to provide the levels of energy required at close to maximal running speed. But in a marathon, a healthy does of caffeine may help, which may serve to explain Frank Shorter's and Bill Rodgers' penchant for drinking flat Coke back in the 70's.
However, there is research to suggest that caffeine offers no such metabolic effect, at least in runners who have carbohydrate loaded and eaten breakfast prior to a race (Weir et al., 1987). So it may be prudent to choose one or the other, rather than carbo-loading and java-loading.
According to Metcalfe (1999), over 100 million American adults drink coffee every day, tossing back an average of 3.1 cups each. And that's just the tip of the caffeine-consumption iceberg. The average American also drinks more than a gallon of soda. Not to mention the pint a day, on average, consumed by the tea drinkers among our caffeine-guzzling population. Many sodas and all but decaffeinated coffees and teas contain varying amounts of caffeine.
"Caffeine makes your heart race, your muscles twitch, your head buzz, your hands shake, your pupils dilate and your bladder full. So why would anyone take it to make them run faster?" asks Weight (2003). And what is all this caffeine doing to our health? Here's a quick run-down of the pros and cons of caffeine consumption.
Although early studies produced possible links between caffeine consumption and heart disease, as well as certain cancers (especially breast cancer), more recent studies have shown no support for those links. And the American Medical Association now states that there is no relationship whatsoever between caffeine intake and cancer.
Caffeine can boost perceived levels of energy. Caffeine stimulates the central nervous system, which can lead to greater productivity. For example, a 150-pound man who drinks as little as one cup of coffee is likely to feel more alert, energetic, and clear-headed.
Caffeine is well-known as a diuretic, therefore, it’s reasonable athletes would have concerns about its effects on hydration. However, several studies have concluded that no changes occurred in core temperature, sweat loss, plasma volume, urine volume or body hydration status during exercise following caffeine ingestion.
As little as 2 cups of coffee a day can raise your blood pressure. The increase isn't big enough to induce hypertension, but if you already have high blood pressure, it may be advisable not to exceed 2 cups of coffee (or its equivalent of other caffeinated beverages) per day.
The FDA recommends that women who are pregnant or are hoping to become pregnant avoid or limit caffeine intake. High caffeine consumption can hinder conception and may lead to miscarriage or low birth weight. Since caffeine will make its way into breast milk, nursing mothers should likewise exercise caution.
If your iron levels are cause for concern, you should know that caffeine can hinder the absorption of iron, particularly if you drink a caffeinated beverage with your meal. Renowned exercise physiologist Dr. Jack Daniels recommends avoiding caffeine for at least 2-3 hours before and after your primary iron intake (whether that is a pill or a steak).
Because caffeine increases blood flow to the kidneys, it acts as a diuretic, making you take more number ones. However, this is more of a problem when one is not exercising. Several studies have indicated that caffeine consumption prior to running does not lead to excessive urination. Scientists are not certain why, but it could be that an increase in adrenaline secretion serves to shut off caffeine's usual effect on the kidneys.
Of course most runners know that caffeine can help elicit number twos as well. Some runners enjoy a cup of joe before a run to clear out their pipes, so to speak. But other runners may find that caffeine, whether in a cup, a can, or a gel packet, can sabotage a run by forcing urgent pit stops. I found this out the hard way when I lived in Seattle. Managing the New Balance store downtown, I was trying to knock out 90-100 mile weeks while working next door to a Starbucks. I spent almost as much time sitting on porcelain as I did running!
Although moderate caffeine consumption can boost perceived energy levels, large levels of consumption - e.g. 10 cups a day for our 150-pound guy or 7 cups a day for a 110-pound woman - may lead to headaches, jittery sensations, nervousness, and irritability.
Under IAAF, the global governing body of our sport, rules the legal threshold for caffeine is 12 ug/ml of urine (The NCAA also limits (15 ug/ml) caffeine usage), yet Elana Meyer stated that all she had “was one cup of coffee at my hotel before the start of the race,” which took place in Bali, Indonesia, during early February this year. “To exceed the limit, Elana would need to have consumed a huge amount of coffee in a very short time, or drunk copious quantites of coke for some hours,” said, Athletics South Africa’s doping specialist, Dr Chris Hattingh. A 175-lb. person could drink seven regular size cups of drip-percolated coffee one hour prior to exercise and would only then approach urinary caffeine limits. Indeed, such a threshold would be hard to exceed without taking caffeine by injection or via a suppository. Vanilla Latte enema, anyone? Anyone?
Elana Meyer is currently consulting the internationally renowned sports doctor, Dr Ryan Kohler, in Cape Town, and is hoping that he will discover just how she arrived at the illegal level of caffeine (15 ug).
Hattingh offered little hope that the A and B samples could have been confused with others because “our testing procedures ensure that there is a ‘custody of the sample’ from the test to the laboratory; it is far more secure than an AIDS test and we all trust them,” Hattingh commented. However, if Elana’s B sample, which is to be tested at the laboratory in Bloemfontein, is also positive it is still unlikely that the elfin star will receive a ban from her federation. More likely is a stern word and a slap on the wrists: “As a first time offender Elana will probably receive a public warning if she is found guilty,” said a spokesperson for Athletics South Africa.
Meyer is not the first high-profile athlete to test positive for caffeine. Back in the late 1990s, Daniel Komen, a Kenyan who broke the 3000m world record also received a slap on the wrists and a brief suspension from competition, despite the fact that the advantages of said stimulant are negligible for the distances at which he was racing.
In the grand scheme of things, with EPO use seemingly on the rise within the upper echelons of our sport and with corrupt governing bodies covering up test results, a few too many cups of coffee may seem like a drop in the ocean of drug abuse. It is, but rules are rules.
Most reading this article are unlikely to ever be frog-marched into a loo, asked to pee into a small plastic container, and give it to an official from USATF, IAAF, or the IOC. Moreover, should we be so requested, most of us are unlikely to ever approach the caffeine levels which might land us in hot water with the powers that be.
Some people have found that caffeine enhances their running performance, but one should use caffeine only in low to moderate doses, especially in the summer (since some water will be lost via elimination). A lot of the improvement associated with caffeine may stem from increased alertness which allows you to focus on a race, rather than through any physiological effect on the muscles propelling you forth at a greater rate.
Since it's use can have potentially time-costly and embarrassing side-effects come race time, I suggest you experiment with caffeine's ergogenic benefits in training first, and chase your java shots with water.
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Caffeine levels in drinks/foods commonly used by runners:
*60mg of caffeine = ca. 1 cup of coffee
For a more comprehensive listing of soft drinks and their caffeine content, click here
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Aldridge, B. (2003). Elana faces up-hill battle. Available at http://www.superrunner.co.za
Bellet, S., Kerschbaum, A., & Finch, E. M. (1968). Response of free fatty acids to coffee and caffeine. Metabolism, 17, 702-707.
Costill, D., Dalsky, G., & Fink, W. J. (1978). Effects of Caffeine Ingestion on Metabolism and Exercise Performance. Medicine and Science in Sports and Exercise, 11 (1), 6-11.
Graham, T. E. & Spriet, L. L. (1991). Performance and Metabolic responses to high Caffeine dose during Prolonged Exercise. Journal of Applied Physiology, 71: 2292.
Metcalfe, E. (1999). Coffee to GO. Available at http://www.runnersworld.com
Noakes, T. D. (1991). Lore of Running. Human Kinetics: Champaign, IL.
Weight, L. (2003). Over The Top. Available at http://www.superrunner.co.za
Weir, J., Noakes, T. D., Myrburg, K., & Adams, B. (1987). A high carbohydrate diet negates the metabolic effects of caffeine. Medicine and Science in Sports and Exercise, 19, 100-105.
National Soft Drinks Association. Caffeine In Soft Drinks. Available at: http://www.nsda.org/SoftDrinks/caffeine.html