Bodybuilders who like to drink should consider the effects of alcohol on both muscles and hormones. A 1989 study of alcohol found that heavy alcohol consumption damages the heart muscle in one third of the subjects, and skeletal muscles in half of them. It’s very clear that alcohol’s toxic effects on muscles are significant and far more widespread than anyone thought.

The study also found that muscle weakness is proportional to the amount of alcohol consumed. But the study also noted that such detrimental effects occurred over a sustained period of heavy drinking. Nonetheless, the study concluded that alcohol is a toxin for striated muscle, regardless of where it is.

A 1983 British study found that three years of heavy alcohol drinking had a negative effect on Type 2B muscle fibers. This is significant because these particular fibers are most subject to hypertrophy or muscular growth. The study further noted that this myopathy (muscle disease) was reversible if the drinking stopped.

Another British study found that alcohol directly inhibited protein synthesis in the quadriceps muscles. Alcohol also interferes with interaction of muscle contractile proteins, and the enzyme that controls the sodium pump mechanism in muscle, causing a localized swelling or edema in muscle tissue.

Consider the effects of alcohol on the endocrine system. Large amounts of alcohol increase the liver breakdown of testosterone 2 – 5 times normal. Alcohol also prevents the conversion of Vitamin A into an active form in the testes. This may cause sterility. Even a single bout of heavy drinking raises cortisol levels (an adrenal stress hormone) enough to cause a significant drop in blood testosterone. Large amounts of alcohol decrease the binding of luteinizing hormone from the pituitary to its receptors in the testes. Luteinizing hormone normally stimulates the testes to synthesize testosterone.

Chronic alcohol intake eventually decreases LH receptors in the testes, thereby making the testes insensitive to LH and lowering testosterone production. Alcohol also interferes with several enzymes in the testes that manufacture testosterone.

By products of alcohol metabolism, such as ecetaldehyde, may exert direct toxic effects on the structure of the testes. In 20% of severe male alcoholics, alcohol lowers testosterone production enough to cause gynecomastia (enlarged breasts). Alcohol also causes impotence or reduced sex drive in 70 – 80% of alcoholic men. Alcohol lowers growth hormone levels, and blunts the normal growth hormone response to decreased blood sugar levels. This may contribute to the higher incidence of hypoglycemia in people who drink, since growth hormone is a body safeguard against hypoglycemia.

While alcohol consists of empty calories, it also decreases the rate of fat burning. In a recent Swiss study, eight healthy young men consumed 96 grams of pure alcohol a day. That equals about 7 cans of beer. This amount of alcohol comprised 25% of their calories. In the first part of the study, the alcohol was added to the men’s usual calorie intake. Later, the alcohol replaced fat and carbohydrate in the men’s diets, equaling the same number of calories. In both instances, alcohol reduced the rate of fat burning in the men by one third.

In addition, the researches found that large quantities of ingested alcohol increase the acetate pool of the body. The significance here is that this excess acetate by product is shunted to peripheral tissues of the body, where it often suppresses fat burning and promotes increased fat deposition.