Alcohol is particularly detrimental for athletes as it interferes with many of the processes so vital to success (3,5). Focus, performance, recovery and rebuilding are all affected. Given that alcohol's effects can linger on for days an athlete would be wise to refrain from its use when competing.
Although alcohol is absorbed rapidly it is metabolized very slowly and its effects may still impact athletic performance up to 48 hours after the last drink.
Assuming the athlete is performing within 48 hours of its consumption, as little as two to three standard drinks can directly:
Decrease strength
Impair reaction time
Impair balance and eye/hand coordination
Impair fine motor and gross motor coordination
Increase fatigue: Liver function is significantly impacted following the ingestion of alcohol. Up to 48 hours after the last drink the liver may still be metabolizing alcohol at the expense of glycogen (metabolized carbohydrate).
Given that glycogen is vital for most of the body's cellular functions, body fatigue, cognitive decline and loss of strength will result when it cannot be used efficiently. Reaction time, balance, coordination are also impacted by this process in addition to the direct aforementioned neurochemical effects alcohol has on the brain.
Interfere with body temperature regulation
Cause dehydration: Alcohol has an impact on kidney function, which interferes with the regulation of electrolytes and fluids in the body (7). Cellular waste removal and nutrient supply are the main functions of fluid and electrolytes, which are controlled through kidney function.
The kidneys filter large amounts of water from many parts of the body, including the brain, to break down alcohol. This causes dehydration and can cripple an athletes performance.
Deplete aerobic capacity and negatively impact endurance for up to 48 hours after the last drink
Impact cellular repair: Protein metabolism is negatively impacted when alcohol is in the system. This has obvious implications for muscle repair.
Impacts the cardiovascular system: Alcohol consumption raises blood pressure and this can result in the heart having work harder to pump blood through the body (8). An abnormally fast heart beat (tachycardia) can also result from alcohol consumption. Further, alcohol increases the synthesis of cholesterol and this can increase the risk of coronary heart disease.
Disrupt sleep: Alcohol significantly interferes with restful sleep (4). It can make falling to sleep easier to begin with due to its sedative effects but the quality of sleep (particularly rapid eye movement) will be disturbed.
Cause vitamin and mineral depletion: Vitamins and minerals so necessary for our health have their absorption interfered with, while the body's own supply are slowly depleted, when alcohol is consumed. Even one or two drinks per day (supposedly the "recommended" amount) can have this effect. B vitamins, which have important enzymatic and metabolic functions are depleted extra rapidly (8).
This deleteriously effects the heart, liver, thyroid and kidneys. Vitamin A is also depleted and this interferes with the body's ability to fight disease. Vitamin C depletion makes one susceptible to anemia. Also, when alcohol is ingested the body excretes calcium at twice the normal rate, thus impacting on bone growth and wound healing.
Cause cognitive impairment: cognitive impairment (disruption of thought processes and brain damage) occur through a number of mechanisms (6,7). Alcohol related sleep disruption contributes to the insufficient restoration of ones neural processes. The effects of GABA-A stimulation, as explained, have been shown to contribute to neural death.
Lack of glycogen to the brain, as a result of alcohol metabolism, causes slow, disoriented, thinking. These are just some factors. There are many more. The implications of cognitive impairment are severe for athletes: loss of motivation, focus and desire in addition to lessened perspicacity and even neuromuscular response.
The effects outlined here are just some of the more obvious ones. There are many others, and it would probably take a book to outline and explain them in sufficient detail.
Conclusion
Even though alcohol will greatly impact performance 25 to 48 hours after the last drink, it has longer lasting, more indirect, effects. The reduction in quality of training and sleep in the period after its consumption, may cause a reduction in performance over the days following this period.
So it is probably best to stay away from alcohol completely when training and competing to win. Indeed, the only real way to avoid alcohol's effects is to refrain from its use completely.
References
What's Your Poison.(1997). [On line] http://www.abc.net.au/quantum/poison/alcohol/alcohol.htm
Aguayo LG. Ethanol potentiates the GABAA activates Cl- currents in mouse hippocampal and cortical neurons. Eur J Pharmacol 1990;187:127-130.
Bloomfield, J. Fricker, P.A. & Fitch, K.D.(1992). Textbook of Science and Medicine in Sport. Blackwell Scientific Publications: Australia.
Walsh J K. Sedative effects of ethanol at night. Journal of Study on Alcohol, 1991, 6, pp. 597-600.
Burke, L.(1992). The Complete Guide to Food for Sports Performance. Allen and Unwin: Australia.
Dodes. L. M.(2002).The Heart of Addiction: A New Approach to Understanding and Managing Alcoholism and Other Addictive Behaviors: Quill, USA.
Hunt WA. Are binge drinkers more at risk of developing brain damage? Alcohol 1993;10:559-561.
Science in Africa.(2004). Alcohol and the Inevitable Hangover From Over Consumption. [On line] http://www.scienceinafrica.co.za/200...ber/drinks.htm
