When it comes to building muscle and improving fitness, what you consume matters just as much as how you train. While many fitness enthusiasts are aware of the importance of protein and rest, the effects of alcohol on muscle growth often go overlooked. I hate to be the bearer of bad news but even occasional alcohol consumption is enough to blunt muscle growth.

In this article, we’ll break down how ethanol (alcohol) impacts your body’s muscle-building processes, explaining the complex processes that occur too.

When you drink alcohol, your body breaks it down into byproducts that create something called reactive oxygen species (ROS). These are unstable molecules that can damage your cells, a process which youve probably heard of called ‘oxidative stress’. 

https://pmc.ncbi.nlm.nih.gov/articles/PMC6668865/#:~:text=Alcohol%20also%20stimulates%20the%20activity,ROS%20(i.e.%2C%20antioxidants).

Your body subsequently turns on a repair process called autophagy, a cellular process that breaks down damaged components, including the mitochondria. Mitochondria are the powerhouses of your cells – they convert the food you eat into energy + many more processes.

One of the pathways in muscle growth is a protein complex called mTOR (short for mechanistic target of rapamycin). Think of mTOR as your body’s growth switch – it helps your muscles grow by regulating hormones like growth hormone and IGF-1 (insulin-like growth factor 1). 

Alcohol inhibits mTORC1 on of the two types of mTOR, which means your body can’t build muscle as effectively. This is especially problematic for anyone trying to recover after a workout because alcohol blocks the boost in mTORC1 activity that usually happens post-exercise. This occurs regardless of whether your a regular consumer of alcohol.

https://pmc.ncbi.nlm.nih.gov/articles/PMC9855961/#:~:text=Overall%2C%20acute%20alcohol%20impairs%20and,the%20alcohol%2Dmediated%20pathway%20inhibition.

There are also hormonal pathways too:

Alcohol reduces the production of gonadotropin-releasing hormone (GnRH), which leads to lower levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These are the two main hormones essential for testosterone production. 

https://pmc.ncbi.nlm.nih.gov/articles/PMC6761906/#:~:text=Together%2C%20the%20available%20evidence%20suggests,alcohol%20itself%2C%20reduces%20GnRH%20secretion.

Drinking alcohol increases the production of a hormone called adrenocorticotropic hormone ACTH, which leads to higher levels of cortisol (the stress hormone) and aldosterone. Aldosterone is a hormone that can lead to problematic water retention, which is why many alcoholics look constantly bloated.

https://pubmed.ncbi.nlm.nih.gov/11912073/#:~:text=Blood%20samples%20were%20drawn%20from,sexual%20maturity%20of%20the%20individual.

High cortisol levels break down muscle tissue, making it harder to gain strength.

For those who wish to continue drinking, albeit too a lesser degree, how long does this inhibited muscle growth last for, so I can better plan my weekends while keeping on track with my fitness goals.

Inhibited recovery: Even a single night of heavy drinking can block muscle protein synthesis (the creation of new muscle) for up to 12 hours.

The last thing to factor in is a heavy session of alcohol can block REM sleep that night of the drinking, so the day after you may want to train lighter and later. Consider booking in a consultation to schedule alcohol consumption without inihibiting muscle growth within your bodybuilding program.