- Alcohol promotes water loss. Alcohol depresses production of the antidiuretic hormone. Increases urination, which increases loss of body fluid increases thirst. For each 10 gm of alcohol consumed (approximately one drink) 4 oz of body fluid is lost.
- Water loss caused by alcohol consumption involves the additional loss of important minerals such as magnesium, potassium, calcium and zinc. These are vital to the maintenance of fluid balance and to nerve and muscle action and coordination.
- Alcohol interferes with the metabolism of fat and glucose. Fats and glucose are diverted into making body fat which accumulates in the liver cells.
- Synthesis of fatty acids is accelerated as a result of the liver's exposure to alcohol. Fat can accumulate in the liver after a single night of heavy drinking.
- The presence of alcohol alters amino acid metabolism in the liver cells. Protein deficiency can develop in heavy drinkers, both from the depression of protein synthesis in the cells and a poor diet.
- Heavy alcohol use can interfere with the intestinal cells' ability to absorb thiamin, folacin, and vitamin B12. Nutrient deficiencies are almost an inevitable consequence of heavy drinking because alcohol directly interferes with the body's use of nutrients, making important water soluble vitamins ineffective even when present in adequate amounts.(Vitamin b12 is important for carbohydrates and fat metabolism).
- Alcohol use can raise blood pressure.
- Two thirds of the calories in beer are alcohol derived (7 Kcal/gm). These calories are used primarily for heat and are not stored as muscle glycogen.
- Use of alcohol causes impaired gluconegenesis and lowers resting muscle glycogen levels.
- Alcohol use results in decreased exercise time to exhaustion and decreased performance in middle-distance running events.
- Athletes engaged in activities that require precise fine motor control, have a perception of reduced tension and increased relaxation as a result of alcohol, but the actual effect is decreased eye-hand coordination and impaired judgment and tracking.
- Metabolism of alcohol interferes with breakdown of lactic acid and can result in build-up of lactic acid in the blood when alcohol is consumed right before or after strenuous exercise.
- Alcohol is a vasodilator: it causes the blood vessels near the surface of the skin to expand and thereby promotes heat loss and lower body temperature.
- The use of alcohol the evening prior to an athletic event may be detrimental to performance. One study showed airline pilots performed consistently worse in task requiring attention and visual-motor coordination skills, 14 hours after igesting enough alcohol to reach a .10-.12 BAC (blood alcohol concentration). This BAC is reached when a 140lb. woman consumes 4-5 drinks in one hour.
- The effects of pot on athletic performance are increased reaction time, decreased finr motor coordination, and increased heart rate. These effects, along with vasodilating effect , cause an athlete to reach maximum heart rate at a lower than normal intensity of exercise, which decreases maximum work capacity.
- Chronic marijuana use has been associated with decreased motivation to perform and to give a maximum effort.
- Cocaine is notable for distorting the user's perception of reality; for example an athlete may perceive increased performance and decreased fatigue in the face of actual decreased performance in both strength and endurance activities.
- Use causes a direct negative effect on glycogenolysis, which affects athletic performance.
- Amphetamines are not known to enhance athletic performance, but enhanced confidence and aggression may lead to 1-2% increase in short-term power activities.
- Use of amphetamines may allow an athlete to tolerate a longer period if anaerobic metabolism, although credible data on this effect are not available.
- Of greater importance are the serious, and sometimes fatal side effects of amphatamine use, such as heatstroke due to shunting of blood away from the skin.
- A more common problem is impaired judgment, which may cause an athlete to participate while injured, possibly leading to worse injury or putting others at risk
Source: UMASS Athletic Health Enhancement Program and Mount Holyoke Health Educator