Alcohol or ethanol is available in different forms such as beer, spirits and wine. Many athletes consume alcohol, whatever their playing level. The consumption of alcohol generally affects the central and peripheral nervous systems as well as having cardiovascular and metabolic effects. For example, those drinking alcoholic beverages may experience increased blood pressure, heart rate, a decrease in blood glucose levels and muscle glycogen levels as well as alterations in mood levels. Tolerance levels do differ between individuals. Alcohol may also have long term effects on the body such as liver problems (especially when consumed daily and in large quantities).

Alcohol in small doses has been reported to improve hand steadiness in sports which require accuracy, such as archery or shooting. However, this seems to be the only slight advantage and alcohol intake is not recommended in any sports although some argue that it reduces tension and anxiety. Alcohol generally has a negative effect on athletic performance although different studies indicate that small doses may reduce the risk of cardiovascular disease.

Some athletes believe that the energy content of alcohol which is greater than that of carbohydrate is advantageous to their performance. However, alcohol is metabolically broken down in the liver and is not taken up and used by the muscle. Furthermore, alcoholic drinks do not contain large amounts of carbohydrates nor contain nutrients that are useful in aiding sports performance. A small beer may contain 12 grams of carbohydrate (CHO) whereas an equivalent amount in orange juice will contain up to three times as much CHO.

Moderate or large consumption of alcohol will impair many aspects of athletic performance such as endurance, strength, speed, reaction time, judgement, coordination, balance and can lead to dehydration due to alcohol being a diuretic. For example, aerobic metabolism is affected and VO2 Max values of athletes maybe drastically reduced. As well, alcohol intake may lead to an increased loss of vital nutrients such as vitamins and minerals. Notably, alcoholics are often deficient in Vitamin C and Potassium/Magnesium). The diuretic effects of alcohol can be dangerous when exercising in hot and cold conditions.

Drinking very small amounts of alcohol may not have an effect on the following day's playing performance although athletes should abstain from any intake around competition. Drinking larger amounts may lead to reduced exercise capacity as mentioned earlier. Athletes should also avoid drinking alcohol immediately before and after competition (alcohol impedes rehydration).


Athletes use amphetamines (such as cocaine) to try to gain a mental and physical advantage over other competitors. Unfortunately this is not the case. Furthermore, their various side effects may lead to serious health related problems. Amphetamine intake triggers increases in blood pressure, heart rate, breathing rate, body metabolism and blood glucose through increasing the levels of the hormones epinephrine, norepinephrine and dopamine (stimulating the central nervous system).

Using amphetamines can lead to various dangers such as:

- Drug dependency and prolonged use increases drug tolerance which may bring about serious cardiovascular disorders such as hypertension or strokes.
- Headaches, nausea, insomnia, dizziness, confusion, paranoia and psychosis.
- Jeopardising health and safety though inhibiting the body's normal mechanisms for perceiving and responding to fatigue, heat stress and pain. Can also lead to uncontrolled weight loss.

As mentioned earlier, athletes take amphetamines as they believe this will improve their performance levels. Some use them for a psychological "get up" before competition to reduce their nervousness and to boost confidence levels. Others believe that they will improve from a physical point of view - strength, speed, stamina.... Scientific research seems to indicate that physical performance is not enhanced. Amphetamines are banned in sport, are illegal (unless provided with a valid medical prescription) and should not be consumed due to their potential health risks.

Most smokers and non-smokers know about the risks of smoking - the more a person smokes the poorer is their future health status. For example, those smoking have a much greater chance of developing serious lung and heart disease. The risk of dying from heart disease for smokers is double that of non-smokers. Smoking has been found to impair performance especially in strenuous endurance events. Smoking causes an increase in airway resistance and will cause athletes to breath harder. It is preferable for both non-athletes and athletes not to smoke at all. Similarly, someone who smokes marijuana regularly may have many of the same respiratory problems that tobacco smokers have.

Caffeine is found is many products ranging from tea and coffee to chocolate and pharmaceutical drugs. The caffeine from taking several cups of coffee has been shown to improve endurance capacity during cycling and swimming although its effect on running seems less influential. For example, a test on athletes running on a treadmill at 70% of their VO2 Max (similar to the effort required by soccer players) did not enhance performance.

Caffeine stimulates the release of fatty acids from the adipose tissue, sparing limited muscle glycogen and increasing endurance capacity. Three cups of coffee may be enough to stimulate fat utilisation although caffeine when ingested as capsules may be more effective. It also has analgesic effects on the central nervous system, increases blood pressure, resting heart rate and may improve alertness and reaction time.

In general, scientific tests are equivocal in their findings about the usefulness of caffeine. Moreover, caffeine is a diuretic and would increase the loss of fluid and amplifying the risk of dehydration, especially in a hot environment. Caffeine may lead to headaches, insomnia, irritability, nausea and abdominal discomfort. Above a certain concentration in the blood, it is a banned substance.

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