Health and Nutrition
Various elements are explored, from nutritional requirements to boost energy levels to the pros and cons of caffeine.
An ABC of nutritional ergogenic aids and dietary supplements.
Where do I find Caffeine in my diet?
The obvious sources of caffeine in the diet are tea and coffee, but there are many other possible sources. Many popular energy drinks contain significant amounts of caffeine, and cold remedies are another common source. The approximate amounts present in some of these products are shown in the table below:
About 70% of UK adults drink coffee and almost 90% drink tea. On average each adult in the UK consumes about 4 cups of coffee a day, and tea consumption per person in the UK is at a similarly high level. Daily caffeine consumption per person in Britain has been estimated at about 400 mg per person. This puts the intake from tea and coffee up in the range of the standard stimulant dose (200mg), and many people exceed this dose by a large amount.
| Foodstuff |
Serving size | Caffeine content (mg |
| Coffee |
150ml |
50-120 |
| Tea | 150ml |
15-50 |
| Hot chocolate |
250ml |
10 |
| Milk chocolate | 50g |
|
Soft drinks: |
||
| Coca Cola |
330ml |
50 |
| Pepsi |
330ml | 40 |
| Jolt | 330ml | 100 |
Tea, coffee and cola drinks are the obvious sources of caffeine in the diet, but many herbal supplements and over-the-counter medicines will supply significant amounts.
Are there any negative effects of Caffeine use?
Caffeine is a drug that induces a low-level addiction in many people, but this in itself is not generally harmful. Caffeine withdrawal for those habituated to its use can, however, produce unpleasant symptoms.
There are a number of potential negative effects associated with the use of caffeine. Caffeine in large doses can disturb the rhythm of the heart, and that is one very good reason for discouraging the use of large amounts of this drug. It is not unusual to experience some cardiac palpitations after a few cups of strong coffee, and again some people are more sensitive to this effect than others. Generally, though, the amounts in the normal diet are entirely safe.
Caffeine is a mild diuretic, acting to stimulate the flow of urine. For this reason, athletes training in hot climates, where sweat losses are large, are often advised to avoid tea, coffee, cola and other caffeine-containing products. This effect is, however, probably over-emphasised, and the negative effects of caffeine withdrawal may be more serious than any possible dehydration that results. Athletes drinking lots of tea, coffee and cola drinks in these conditions will need to be careful to drink lots of other fluids too.
Potential problems with caffeine
Caffeine is a weak diuretic and its use is often discouraged because of this, especially when athletes are living in the heat. This is probably overplayed: the diuretic action is weak in those used to caffeine, and caffeine withdrawal is more of a concern.
People not used to caffeine who take large doses will experience muscle tremor and CNS symptoms.
THE BOTTOM LINE.
Is it worth trying?
Yes, definitely, but the sensible athlete will experiment with different doses of caffeine in training to find their individual response rather than leaving it to race day to experiment and maybe get it wrong.
