Are you a caffeine addict?
2004-04-23 11:54
Cape Town - Caffeine has been described as being the most widely ingested psychoactive drug in the world. It is well known that chronic caffeine ingestion can lead to dependence and unpleasant withdrawal symptoms.
Many people tend to drink more coffee or tea when they are doing high volume training - or work - in an effort to 'stay awake'. This caffeine injection sometimes masks their fatigue.
And if you drink more than two cups of coffee or tea a day, there is a good chance that you are addicted to caffeine.
General health
So now you're probably wondering whether caffeine is bad for you. We have summarised what the current literature has to say, and you can judge for yourself.
Blood pressure: Caffeine intake should be limited or avoided by individuals with high blood pressure.
Osteoporosis: To prevent or limit further damage, it is recommended that caffeine intake be limited to less than 150mg per day (as caffeine increases magnesium and calcium excretion in the urine).
Pregnancy: High intakes of caffeine have been linked to spontaneous abortion, and more recently Sudden Infant Death (SIDS) in mothers who ingest large amounts of caffeine during and post-pregnancy (smoking and alcohol consumption have a joint negative effect). It is recommended that pregnant women should not ingest more than one cup of coffee (or caffeine equivalent) a day.
Menopausal 'hot flushes': Caffeine has been found to aggravate menopausal 'hot flushes'. Regular physical activity, a balanced diet, avoidance of alcohol and caffeine, and stress reduction may aid the reduction of these flushes.
Weight reduction: Caffeine is commonly added to thermogenic agents recommended for fat weight reduction. Although these may initially help, the body seems to adapt to the dose, resulting in limited long-term benefits.
Withdrawal symptoms
Cutting back on your caffeine intake may result in some unpleasant withdrawal symptoms, such as an increased frequency and severity of headaches, increase in sleep time or sleepiness (and yawning!), fatigue, a decrease in vigour, and irritability.
Overdosing
If you're getting too much caffeine - as in more than 500mg a day - then you may initially feel some positive effects such as elation, peacefulness and pleasantness.
However, the negative effects will follow sooner or later. These include tension, nervousness, anxiety, excitement, irritability, nausea, palpitations and restlessness.
Caffeine in sport
Caffeine is listed as a stimulant on the International Olympic Committee's (IOC) list of banned substances.
A limited intake is allowed by the IOC, but if your urine contains more than 12 micrograms of caffeine per millilitre of urine, you will test positive for a banned substance.
So how much coffee or other caffeine-containing substances can you consume before the IOC will slap a ban on you? Well, 1200mg of caffeine a day or 500mg in a short time will do the trick, so don't drink 6 to 8 cups of coffee or 10 cans of a cola drink over a short period. Also, don't eat three bars (200g) of chocolate in a short time.
Obviously you are unlikely to drink so much coffee or cola in such a short time, so this shouldn't pose a problem for you. You are more likely to have a positive IOC test through the consumption of 'rave' drinks or thermogenic preparations (used for cutting body fat), as these tend to have high concentrations of caffeine.
Ironically, the beneficial effects of caffeine have been noted in doses below the IOC limit. Higher doping doses of caffeine are probably used more for accentuating the effect of the more potent but more dangerous stimulant, ephedrine, than for any physiological or psychological benefits directly from the caffeine.
Recent research
Due to the amount of caffeine consumed in modern society, there is constant research into the effects of caffeine on sporting performance. Here are a few of the latest findings:
Glucose uptake: A carb-electrolyte solution with 150mg caffeine per litre improves intestinal glucose uptake.
Runners' high: 6mg caffeine per kilogram of body weight 90 minutes before prolonged exercise lowers the threshold for exercise-induced beta-endorphin and cortisol release, meaning the release point will be reached earlier.
This is beneficial to the runner, although the caffeine does not have glycogen-sparing effect.
Improved endurance: Through its wide range of physiological and psychological effects, caffeine improves endurance capacity in well-trained athletes.
Delayed fatigue: Caffeine dosing before exercise delays the onset of fatigue and may enhance performance of high intensity exercise.
No more speed: Caffeine ingestion (6mg/kg) does not improve high intensity sprint performance.
IOC-friendly: Doses of carb-electrolyte solution containing up to 320mg caffeine per litre do not result in urinary excretion higher than the IOC limit.
Anti-creatine: Caffeine nullifies the potential beneficial effects of creatine supplementation.
Glycogen-sparing: 9mg/kg in trained athletes had a glycogen-sparing effect in prolonged aerobic high intensity exercise, but not for untrained athletes.
Mineral loss: Caffeine-containing soft drinks (caffeine content not specified) increases urinary excretion of magnesium and calcium.
Rehydration: Caffeine-containing beverages are not recommended after exercise due to the diuretic effect. It increases urine volume.
Safe use
Caffeine can help your running performance, but only if taken in the correct doses and at the right time.
These seven tips will help you get your caffeine fix so that it will help your performance.
Avoid caffeine if you have high blood pressure (hypertension).
Read product labels carefully or contact the manufacturer or distributor. Elite athletes should request caffeine (guarana and MaHuang/ephedrine) content in writing.
A caffeine intake of 3 to 6mg per kg body mass may improve your endurance performance. To gain potential benefits, refrain from your usual caffeine intake for at least 7 days before the event (preferably avoid it). Then take 3 to 6mg (up to 9mg) per kg body weight at least 90 minutes prior to the event, preferably in the form of coffee, as hot beverages appear to be more effective. Caffeine tolerance varies, so try it out in training first. As a precaution, elite athletes should have pre- and post-run urine samples tested before using this for a major event.
Limit your coffee intake to 1 or 2 cups per day (or the equivalent caffeine content in other products).
Avoid caffeine - and alcohol - if you are using a creatine supplement.
High doses of caffeine (apart from the IOC banning) may be negative for your performance, due to an increase in anxiety, irritability and mild dehydration.
If you have a stomach or duodenal ulcer, preferably avoid an excessive caffeine intake.
What's in a product?
Caffeine content
100g Chocolate sweets 16mg
340ml (can) Cola cold drinks 35mg
Caffeine content per cup (200ml)
Coffee (ground or filter) 116mg
Coffee (instant) 82mg
Decaffeinated coffee 4mg
Tea (leaves) 41mg
Tea (bags) 27mg
Cocoa/Hot chocolate 6mg
Chocolate milk 5mg
Energy drinks
1 can Red Bull 80mg
Other Products
30ml Bioplus 270mg
1 effervescent tablet Guronsan-C 50mg
1 tablet Pynstop 45mg
1 tablet Syndol 30mg
(alkaloid caffeine)
1 tablet Regmakers 150mg
1 tablet 'Lert 180mg