A glass of wine in the evening, a beer after the match – for most people that is not something to think about for long. Anyone who trains regularly does notice at some point, though, that the session the next day goes differently. This article explains matter-of-factly what happens in the body as soon as alcohol arrives: why metabolism puts everything else on hold, what that means for muscle building, recovery and sleep, how much energy is in a glass and how to put that in a realistic context. This is not about a ban, but about an honest calculation.
What happens when alcohol arrives
The course puts it in a single, very clear sentence: «Alcohol is toxic for every cell of the body. The body wants to break the poison down as quickly as possible, in the course of which it neglects digestion and other metabolic processes and brings about a short-term relaxation of the stomach muscles.»
This sentence comes from the chapter that dismantles the myth «schnapps helps with digestion» – and it simultaneously explains why this myth is so persistent. The short-term relaxation of the stomach muscles creates the feeling of now digesting a heavy meal better. In reality, digestion is being slowed down in the process, because the body puts it to one side. The digestive schnapps is thus one of those fitness and nutrition myths that survive because what you feel is the opposite of what is happening.
The principle behind this carries everything else: breaking down the alcohol takes priority. It happens in the liver, at a largely fixed speed, and can neither be accelerated nor skipped. As long as it is running, other metabolic processes recede into the background – not because they are unimportant, but because detoxification has priority.
The energy nobody counts in
Alcohol is a supplier of energy. The course lists it alongside carbohydrates, fats and proteins as an additional energy carrier, while at the same time noting that its significance in quantitative terms is small in a healthy person. For daily nutrient supply that is true – for the energy balance when losing weight it looks different.
Alcohol supplies around 7 kilocalories per gram. That puts it between the macronutrients: carbohydrates and protein each provide about 4 kilocalories per gram, fat has the highest energy density at 9. A calculation makes this tangible:
- 1 decilitre of wine at 12 per cent by volume contains around 9.5 grams of pure alcohol – about 65 kilocalories from that alone, without the residual sugar.
- 5 decilitres of beer at 5 per cent by volume contain around 20 grams of alcohol, that is, about 140 kilocalories – plus the carbohydrates.
Two glasses of wine in an evening therefore roughly correspond to a snack that appears in no food diary. On top of that comes a second effect: as long as the body is busy with the breakdown, the use of the rest of the energy taken in recedes into the background. Anyone who plans a calorie deficit and does not count the alcohol is calculating past reality. How the body supplies energy at all and in what order it does so is described in the article on energy supply; the basics of counting are in the article What actually are calories?.
Muscle building: the metabolism that gets displaced
Muscle building is not a state but a constant balance. The musculature is subject to permanent build-up and breakdown; whether anything is added on balance is decided by whether protein synthesis outweighs protein breakdown. Strength training alone does raise the synthesis rate, but without a supply of protein it still leads to a negative balance – only the interplay of the training stimulus and sufficient essential amino acids tips it into positive. These connections are described in the article on protein synthesis.
This is exactly where the prioritisation described by the course takes hold. While the body is breaking down alcohol, it puts other metabolic processes on hold – and the building of new muscle proteins is one of the processes that has to wait. The effect is qualitative, not dramatic: one glass does not wipe out a training session. But of all times, it is in the hours after the session, when the synthesis rate is elevated and the stimulus is being processed, that the breakdown of alcohol competes with what you actually want. An after-work beer straight after strength training therefore hits the least favourable moment.
Recovery and sleep
Adaptations do not take place during the load but in the recovery – recovery is therefore a plannable component of training and not what is left over. Alcohol intervenes in this recovery at two points.
Firstly through sleep. Alcohol makes many people fall asleep more quickly, but it worsens the second half of the night: sleep becomes more restless and less restorative. Because sleep is the single strongest recovery factor, this weighs more heavily than the calories. Secondly through the metabolic work itself: a body that is detoxifying at night is not at the same time recovering maximally from a hard session.
Fluid balance and blood sugar
Alcohol has a diuretic effect – you excrete more fluid than you take in with the drink. That is more relevant than it sounds: water is the first limiting nutrient and, in many physical activities, the most important performance-limiting factor. A drop in performance can already occur at a water loss of 2 per cent of body weight – at 75 kilograms that is around 1.5 litres. So anyone who drinks the evening before and trains in the morning may be starting with a deficit. For orientation: basic fluid intake for healthy adults is two to three litres per day, with another 0.4 to 0.8 l per hour of sport. More on this in the article Drinking in everyday life.
With blood sugar the same priority mechanism applies. The liver, which otherwise provides glucose when needed, is busy breaking down alcohol and fulfils this task less well. Blood sugar can therefore drop lower than expected – especially in combination with sport, little food and several hours in between. For people with diabetes this is not a marginal topic but belongs expressly in medical advice.
Realistic assessment instead of a ban
The Swiss food pyramid, which the course follows, places alcohol together with sweets and salty things among the indulgence foods: they should be enjoyed in moderation. The further recommendations for a healthy lifestyle also state that smoking and excessive alcohol consumption should be avoided. That is the position – no ban, but no playing down either.
For practice that means:
- Count it in. Alcohol belongs in the energy balance. In the dietary history it is expressly recorded in the course – alongside salty snacks, meat and sausage products.
- Keep a distance from training. Straight after the session it hits recovery hardest. Anyone who drinks is better off doing so on a rest day or with a clear gap.
- Abstain before competitions and hard blocks. In phases where every hour of recovery counts, abstaining is the simplest lever.
- Water alongside. That at least partly compensates for the fluid loss.
Honesty requires one boundary to be drawn: in nutritional counselling this is about reduction as part of a dietary goal – for instance showing the client how much energy actually adds up through sweets, salty foods and alcohol, and working out viable alternatives with them. As soon as consumption is a health problem in its own right, this remit ends. It is no coincidence that the course material lists alcoholism as one cause of an unbalanced diet with corresponding nutrient deficiencies. In such cases the right address is a medical or therapeutic specialist service, not the training plan.
Course tip from update Akademie: If you want to support athletes with nutrition questions, the Sporternährungscoach programme at update Akademie is the right route. It covers energy balance and the individual nutrients, ways of eating, fat loss and muscle building, hydration as well as nutrition around competition – plus evidence-based practice and conversation technique, so that you can handle such topics in a consultation factually rather than moralistically.
Frequently asked questions about alcohol and training
Does a glass of wine ruin my training?
No. A single glass undoes neither a session nor a training week. What is decisive is the quantity, the frequency and the interval before training – not the single glass.
How long should I wait after training?
The bigger the gap, the less the breakdown of alcohol overlaps with the recovery phase. As a workable guide: on intense training days abstain if possible, and drink on rest days, if at all.
Is beer after sport a good recovery drink?
No. Beer does supply fluid and carbohydrates, but at the same time it has a diuretic effect and occupies metabolism with breaking down the alcohol. Alcohol-free beer does not have this disadvantage.
Why is muscle soreness worse after an evening with alcohol?
What is established is that recovery overall goes worse: poorer sleep, a metabolism busy with detoxification and frequently a fluid deficit. How you subjectively feel the next day follows from this sum.
Does alcohol really count as calories, even though it is not a nutrient?
Yes. In technical terms alcohol counts as an additional energy supplier, even if its significance for nutrient supply is small in quantitative terms. In the energy balance it counts at around 7 kilocalories per gram.
Conclusion
Alcohol costs more than what is on the label. The body treats it as a poison to be broken down with priority and puts other metabolic processes on hold for that – digestion, building processes, the provision of glucose. On top of that come the energy that is rarely counted in, the poorer sleep and a fluid deficit that can measurably affect performance the next day. No ban follows from this: as an indulgence in moderation, alcohol has its place. But anyone currently working towards a goal should know that they are spending recovery on it – and not just calories.
