Alcohol and training: what a business dinner costs your fitness
Alcohol does not cancel a training session, but it slows what happens afterwards. It disrupts sleep in the second half of the night, increases fluid loss, adds seven kilocalories per gram and, in large amounts, reduces muscle repair after exercise. The United Kingdom's Chief Medical Officers advise adults not to drink more than 14 units a week on a regular basis, spread over three days or more, with several drink-free days. One unit is 10 millilitres of pure alcohol: multiply the volume of the drink in millilitres by its strength in per cent and divide by 1,000. A 175-millilitre glass of wine at 13% is 2.3 units, so a bottle shared between two at dinner is about five units each. No level of drinking is free of risk; the guideline describes low risk, not safety.
Count your units
Enter your usual drink and how many you have in a week. One unit is 10 ml of pure alcohol.
- Units in one drink
- 2.3
- Units per week
- 22.8
- UK low-risk guideline
- Above the 14 units a week
The UK guideline of 14 units a week describes low risk, not safety.
Counting what you actually drink
Most people who drink at business dinners underestimate their intake, because glasses are refilled and measures at home are generous. The unit system removes the guesswork.
Units = volume in millilitres × strength in % ÷ 1,000.
- A 175 ml glass of wine at 13%: 2.3 units.
- A 750 ml bottle of wine at 13.5%: about 10 units.
- A 330 ml bottle of beer at 5%: 1.7 units.
- A 50 ml double measure of spirits at 40%: 2 units.
- A flute of champagne, 125 ml at 12%: 1.5 units.
The calculator above works out the units in your usual drink and multiplies them by how often you have it. Two glasses of wine at five dinners a week is 23 units, well above the guideline, without a single evening that felt excessive.
What the guideline says
The low-risk drinking guidelines published by the UK Chief Medical Officers apply equally to men and women.
- Not more than 14 units a week on a regular basis.
- If you do drink that much, spread it over three days or more.
- Have several drink-free days each week.
The guideline is explicit that the risk of several cancers rises with any regular drinking, and that there is no level that can be called safe. Fourteen units is the level at which the lifetime risk of dying from an alcohol-related condition is judged to be low, about one in a hundred.
Sleep: the largest effect on next-day performance
Alcohol makes people fall asleep faster, which is why it is mistaken for a sleep aid. As it is metabolised during the night, sleep becomes lighter and more fragmented, with more awakenings in the early hours. The result is a night that looks long enough and restores poorly.
For someone training the next morning, this matters more than any direct effect on muscle. See sleep for executives.
Recovery and adaptation
Training produces its benefit afterwards, when the body repairs and adapts. Heavy drinking after exercise has been shown in controlled studies to reduce muscle protein synthesis even when protein is consumed alongside it. Moderate amounts have a much smaller effect.
Two other mechanisms are simpler.
- Fluid. Alcohol increases urine output. After a session in which you have sweated, it delays rehydration. See hydration.
- Energy. A bottle of wine contains about 600 kilocalories, and alcohol loosens restraint over what is eaten with it. See calorie needs.
The morning after
A hard session with a hangover is poor training and carries some risk. Heart rate is higher at a given effort, coordination is reduced and you start dehydrated. In the heat, the risk of heat illness rises. See training in the heat.
The sensible choice after a heavy evening is an easy walk, plenty of water and food, and the hard session moved by a day.
Managing a week of dinners
People whose work involves entertaining cannot avoid the situation. They can manage it.
- Decide before you sit down. One glass, two, or none, chosen in advance, is easier to hold than a decision made at the third refill.
- Keep your glass full of water. Waiters refill empty glasses.
- Order first. Sparkling water with lime looks like a drink and ends the conversation about what you are having.
- Alternate. One glass of water for each glass of wine halves the pace.
- Fix the drink-free days. Choose them at the start of the week, around your hardest training sessions.
- Stop early. Alcohol finished three to four hours before bed disturbs sleep less than a digestif at midnight.
In many business settings in the Gulf, not drinking is unremarkable and requires no explanation. Elsewhere, "I'm training in the morning" is rarely questioned.
Who should not drink at all
Alcohol is to be avoided during pregnancy, with certain medicines, with liver disease, and by anyone who finds that limits do not hold. If you drink more than you intend to, regularly, that is worth discussing with a physician rather than with a coach.
What a coach can and cannot do
A coach will notice the pattern before you do: flat sessions on Thursday mornings, a resting pulse that is higher after certain evenings. See resting heart rate. What to do about it is your decision; the data make it easier to take.
The 14-unit figure is a guideline for low risk, not a recommended amount. Drinking less is better for health at every level.
Questions
How many units of alcohol are in a glass of wine?
Multiply the volume in millilitres by the strength in per cent and divide by 1,000. A standard 175 ml glass at 13% contains 2.3 units, a large 250 ml glass 3.3 units, and a 750 ml bottle about 10 units. Restaurant pours and glasses refilled at the table often exceed the standard measure without your noticing.
Can I train the day after drinking?
After one or two drinks, yes, with little effect. After a heavy evening, replace the hard session with easy activity: you are dehydrated, your heart rate is higher for the same effort, and coordination is poorer, which raises the risk of injury and, in hot weather, of heat illness. Move the demanding session to the following day.
Does alcohol stop muscle growth?
Large amounts taken after training reduce muscle protein synthesis, even when protein is eaten at the same time. One or two drinks have a much smaller effect. The indirect effects weigh more over time: alcohol fragments sleep, slows rehydration and adds energy without nutrients, all of which limit what you gain from training.