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Alcohol and Your Muscles

Dr Paul Henning PhD, CSCS, CISSN

Hey, let’s grab a drink after work!  

What the heck, a couple can’t hurt, right?

Often when people want to improve their health and their body, the habitual alcohol intake is the first think that thwarts them.  Then the questions start to get negative, 

“Do I have to shun alcohol for all eternity?”

“Can I never, ever have a drink?…I want to have a life ya know!?” etc. etc.

I’m not here to turn you into a tea-totaler, unless you want to of course.  However, the fact is, most adults drastically underestimate two things.

  1. How much they really do drink and 
  2. The affect alcohol has on their ability to get great results from exercise.

Alcohol requires no digestion and is absorbed directly into the blood stream from the stomach lining or the lining of the small intestine into the portal vein leading to the liver.  We have no storage mechanism for alcohol so once it arrives in the liver the enzymes alcohol dehydrogenase and aldehyde dehydrogenase immediately go to work to metabolize it. 

The metabolic by-products of alcohol cause increased fatty acid production and also decrease oxidation (burning) of fat and fatty acids, which results in a build up of these substances in the liver.  Eventually, fatty liver and elevated triglycerides ensue.

 As if the metabolism of alcohol itself isn’t bad enough, it just gets worst when we take a look at what alcohol does to our metabolism and its affects on the metabolism of energy substrates.

Research has confirmed the consumption of only one drink decreased our ability to metabolize fat and carbohydrates.  It also decreased leptin levels. Leptin is an important hormone that’s responsible for regulating energy intake/expenditure [5].  

While on the topic of hormones, let’s take a look at how some are affected by alcohol.

What are hormones?

Hormones are chemical messengers that coordinate many functions within the body and control four major areas:

  1. production, use, and storage of energy
  2. reproduction
  3. maintenance of the internal environment
  4. growth and development [1]. 

For hormones to function properly; their amount and the timing of their release must be finely coordinated and target tissues must respond to them accurately.  Hormones can be affected by many variables-such as food/drink, type and amount of exercise, stress levels, and sleep. Eating well balanced meals and incorporating the right type and amount of exercise will ensure that you are doing the best to keep healthy levels of hormones (e.g. insulin).  

Hormones & Alcohol

Speaking of food and drink and their effect on hormones, let’s examine one specific recreational drink that clients often ask about.  It usually shows up in questions like these: “Can I get away with it?” or “How much is ok to have?” or “Can I still drink my beer on the weekends and get a great body?” 

That last one is one of my personal favorites!

It’s known that alcohol can impair the functions of hormone-releasing glands and the target tissues, thus causing medical consequences such as malfunction of the gonads and dysfunction of parathyroid.  Long term alcohol abuse causes degeneration of liver cells, which results in carbohydrate disorders [2] and impairs glucose metabolism [3].  In addition, alcohol stimulates hormones (aldosterone and glucocorticoids) which negatively affect skeletal muscle metabolism [4].  

Understanding how hormones are affected from excessive alcohol consumption is important in comprehending how muscle growth could be impaired.  Excessive alcohol consumption for a 70 kg man is considered to be about 5-6 glasses of beer in one sitting that are 4.5 to 6% alcohol content.

So, what DO we know about alcohol consumption, the effect it has on hormones, and how those alterations may alter muscle growth?

Alcohol effects muscle  

Below are some key bullet points on research-based effects of alcohol on muscle growth and protein synthesis.  Remember protein synthesis is the underlying cellular process that builds new muscle proteins to repair and grow muscle!  Of course, we know muscle is a huge metabolic catalyst!

  • Alcohol affects the type II (especially type IIx) muscle fibers, which are more responsive to muscle growth [5].  The type II muscle fibers are the stimulated the most by intense resistance exercise and are responsible for building the muscle.
  • There is a 15-20% decrease in basal protein synthesis in skeletal muscle 24 hours after an acute episode of alcohol intoxication [6].  This is clear evidence that alcohol intoxication depresses our muscle protein building machinery; definitely not ideal!!  
  • Alcohol compromised the ability of insulin and IGF-I to slow proteolysis [6] which is the breakdown of proteins into amino acids.  Basically this means that alcohol negatively affected two hormones ability to stop muscle proteins from being utilized for fuel.

Alcohol effects on hormones

Hormones influence muscle growth.  In fact, our hormonal profile determines whether muscle is built up (protein synthesis) or broken down (protein degradation).  

  • High doses of alcohol (1.5 g/kg) are shown to suppress testosterone by 20-25% after acute ingestion.  This is assuming that a glass of beer is approximately 12 oz (355 ml) and on average its alcohol content is between 4.5 and 6%.  A dose for a 70 kg man would be about 5-6 glasses of beer.
  • A study demonstrated that during a recovery period from heavy resistance exercise, post exercise alcohol ingestion (1 g/kg lean mass) affected the hormonal profile including testosterone concentrations and bioavailability [7].  This means that alcohol negatively affected the testosterone available to bind to its receptor and perform its natural function inside cells.
  • Numerous studies back this up by demonstrating that testosterone levels decrease after alcohol consumption [8-10].
  • There are studies that show an increase in cortisol levels from alcohol ingestion.  Cortisol is a catabolic hormone and chronic elevations in cortisol are not what we want in our bodies when undergoing a physique transformation.  It’s believed that the stressful effects of alcohol into the body may be responsible for the increase in cortisol levels.  

Still asking if you can ‘get away with it’?

  • Main findings in research are that there is a dose dependency in the hormonal response to alcohol consumption.
  • Keep in mind that alcohol negatively affects the bioavailable testosterone.  Again this is not good because this is the testosterone that binds to receptors and cause good things (i.e. gene expression) to happen for muscle growth.  
  • For a 70 kg individual, 1.5 g/kg of alcohol is 136 grams of alcohol. This is approximately 5-6 glasses (12 oz.) of beer containing between 4.5 and 6% alcohol content.
  • Protein synthesis and resulting muscle growth appears to be negatively affected by alcohol.
  • Cortisol levels (stress hormone) increase from too much alcohol which further impairs protein synthesis and causes protein/muscle breakdown.

Recommendations – is it ok to have a few drinks a week?

There are some really negative effects from consumption of alcohol on muscle recovery and body composition results from exercise.  There is no two ways to sugar-coat it so I will answer your question this way…  

If you’re just starting on your transformative health & fitness journey and/or you come from a history of “over-indulgence” then give yourself a fighting chance.  It may be a great idea to ditch the booze for a while as you allow yourself to get use to frequent exercise and this new way (much better) way of eating. As you start seeing results, it might be okay to award yourself occasionally.  Most importantly, as you get better at this you will learn where and when alcohol may fit into your new high-performance lifestyle! 

References

1. Riddle, R.C. and T.L. Clemens, Insulin, osteoblasts, and energy metabolism: why bone counts calories. The Journal of clinical investigation, 2014. 124(4): p. 1465-7.

2. Wolszczak, B., E. Zasimowicz, and J. Juchniewicz, [The effect of ethanol on the endocrynic system]. Polski merkuriusz lekarski : organ Polskiego Towarzystwa Lekarskiego, 2014. 36(211): p. 45-7.

3. Siler, S.Q., et al., The inhibition of gluconeogenesis following alcohol in humans. The American journal of physiology, 1998. 275(5 Pt 1): p. E897-907.

4. Reichman, M.E., et al., Effects of alcohol consumption on plasma and urinary hormone concentrations in premenopausal women. Journal of the National Cancer Institute, 1993. 85(9): p. 722-7.

5. Andersen, J.L. and P. Aagaard, Myosin heavy chain IIX overshoot in human skeletal muscle. Muscle & nerve, 2000. 23(7): p. 1095-104.

6. Hong-Brown, L.Q., R.A. Frost, and C.H. Lang, Alcohol impairs protein synthesis and degradation in cultured skeletal muscle cells. Alcoholism, clinical and experimental research, 2001. 25(9): p. 1373-82.

7. Vingren, J.L., et al., Postresistance exercise ethanol ingestion and acute testosterone bioavailability. Medicine and science in sports and exercise, 2013. 45(9): p. 1825-32.

8. Kumar, V., et al., Human muscle protein synthesis and breakdown during and after exercise. Journal of applied physiology, 2009. 106(6): p. 2026-39.

9. Rivier, C., Alcohol rapidly lowers plasma testosterone levels in the rat: evidence that a neural brain-gonadal pathway may be important for decreased testicular responsiveness to gonadotropin. Alcoholism, clinical and experimental research, 1999. 23(1): p. 38-45.

10. Selvage, D.J., D.B. Hales, and C.L. Rivier, Comparison between the influence of the systemic and central injection of alcohol on Leydig cell activity. Alcoholism, clinical and experimental research, 2004. 28(3): p. 480-8.



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