You might not want to hear it, but alcohol has a negative effect on your training progress. No big news. But to what extend does alcohol effect your training progress? Good news: the take home message will not be “never drink again”. After reading this article, you will know exactly what the effect of alcohol is. You can therefore make your own rational decision.
Several scientific studies show a positive relation between being an athlete and alcohol consumption. Now I’m not talking about the “positive relation” you would expect. They found that athletes are more likely than the general population to drink alcohol to excess. When drinking alcohol to excess, one study reported a mean of 12 standard drinks (!) per person.
To make sure this article is relevant for all of you, we look at a scientific study where participants combine strength, endurance and peak power sprints. Since most sports have a mix of those three ingredients, this workout represents most training sessions. In chronological order:
- warm-up (10x leg extension, 50-60% of 1 repetition maximum)
- resistance exercise (8×5 reps leg extension, 80% 1RM)
- 5 minute recovery
- continuous exercise (30 min cycling at ~70% VO2max)
- 2 minute recovery
- high intensity intervals (10×30 seconds at 110% peak power output with 30 seconds recovery in between)
There were 3 experimental trials. Participants did all 3 experiments, with 2 weeks recovery in-between.
- Post-exercise ingestion of alcohol & carbohydrate (ALC-CHO)
- Post-exercise ingestion of alcohol & protein (ALC-PRO)
- Post-exercise ingestion of protein (PRO)
Carbohydrates or proteins (25 grams per serving) were consumed immediately after exercise and 4 h later. Alcohol consumptions were based on the previous mentioned scientifically reported amount of drinks when athletes drink to excess. Participants started consuming alcohol 1 h post-exercise. There were 6 alcohol servings within 3 hours. The alcohol servings contained 60 mL vodka, which I would personally call a “double shot”. Good luck with that.
Fast forward to the results. If you want to recover and get fitter after exercise, you want your muscles to recover and grow strong. Your body does this by increasing muscle protein synthesis (production). The researchers measured muscle protein synthesis via muscle biopsies – pieces of muscle tissue removed from the participants. This is what happens:
When comparing to an ideal situation (PRO), alcohol reduced muscle protein synthesis by 24% (ALC-PRO). When you combine alcohol with carbohydrate instead of protein (ALC-CHO), muscle protein synthesis is even reduced by 37%. For those of you who are not shocked, I would like to address two more things.
First, we are missing a fourth experiment in which participants are only consuming alcohol (ALC). Chances are that the muscle protein synthesis would then drop below muscle protein synthesis before workout. This means you are better off not exercising then exercise with post-exercise alcohol consumption.
Second, this study only looked at protein synthesis. If you want the full results you need to look at protein breakdown as well. With no food intake and no exercise, the protein syntheses before workout was positive, but definitely not greater than the protein breakdown, resulting in a negative muscle protein balance. Often, exercise itself does not even increase protein synthesis above protein breakdown. It is quite clear alcohol decreases potential protein synthesis. Chances are it also increases protein breakdown. Then again you would be better off not exercising then exercise with post-exercise alcohol consumption. If this would be the case, a graph like this would be more realistic:
Summary and personal thoughts
Athletes are more likely than the general population to drink alcohol to excess. Excessive drinking post-workout probably diminishes all positive muscular effects, regardless of workout type. You could expect less negative effect when drinking less alcohol, but the effect will still be there. Should you never drink again? That is all up to you. But if you do, try to combine it with proteins and accept a decrease in (potential) fitness progress. Cheers. 
Founder of Molab, Human Movement Scientist and Freelance Content Marketer.