Disclaimer: Drinking alcohol underage is illegal. If you are suffering from alcoholism, consult a medical professional or call 1-800-662-4357.

What if we told you that the headache you experience after a night of drinking is just scratching the surface of alcohol’s effects on your body? From a reduction in endurance to poor recovery, drinking too much alcohol can mess with your swimming goals…big time!

Let’s take a closer look at how alcohol impacts the body, and what it means for your swimming performance.

What is Alcohol?

There are three types of alcohol:

  • Methanol: Found in pesticides and fuel
  • Isopropanol: Found in rubbing alcohol and other cosmetics
  • Ethanol: Found in alcoholic beverages, perfumes, mouthwashes

Related: What Happens To Your Body When You Swim

We’re going to focus on ethanol for the purposes of this post. Ethanol is produced by the fermentation of yeast, sugars and starches, and is the intoxicating agent found in beer, wine and liquor. The chemical formula for ethanol is C₂H₆O

How Alcohol Affects the Body

Alcohol is a central nervous system depressant that slows down parts of the brain and impairs cognitive function. However, alcohol doesn’t affect everyone equally. The severity of effects depends on a few factors:

  • Amount of alcohol consumed
  • Sex
  • Body size
  • Environment
  • Individual tolerance

Alcohol can stay in the body for up to 72 hours after consumption, but the overall time varies depending on the part of the body you’re looking at:

  • Blood: 6 hours
  • Breath: 12-24 hours
  • Urine: 72 hours
  • Saliva: 12-24 hours
  • Hair: Up to 90 days

How Alcohol Impacts Swimming Performance

Consuming alcohol has a laundry list of negative effects on your swimming performance and overall health. Let’s take a look.

Reduces Endurance 

Alcohol impacts the production of ATP, which is our muscles’ primary energy source. If you try to do a really tough workout after a night of drinking, you probably won’t feel 100%.

Related: 5 Ways to Pace for Long Distance Swims

Slower Reaction Time

Alcohol is a sedative that impacts performance for up to 72 hours. If you go for a swim when you’re hungover, you may notice that your reaction time is much slower than usual.

Slows Down Muscle Growth

Alcohol reduces testosterone which is needed for muscle growth and recovery in both men and women. If you want to make big gains, consider reducing your alcohol intake.


Alcohol is a natural diuretic. It inhibits the production of the antidiuretic hormone vasopressin, which plays a role in water excretion. So, when you drink, you might pee more, which can result in dehydration. Keep this in mind if you plan to swim after drinking!

Impacts Recovery & Sleep

Related: Recovery Tips for Swimmers

If you drink alcohol up to six hours before going to sleep, your sleep pattern may be interrupted. This can reduce the amount of Human Growth Hormone (HGH) the body produces, which can impact muscle recovery. And, you’ll feel that sleep deprivation the next morning!

Poor Memory

Most memory formation occurs while you’re sleeping, so if you drink alcohol before bed, your memory might suffer. Alcohol slows the temporal lobe, which is the part of the brain that forms memories. 

Impacts Nutrition Goals

Your muscles can’t use alcohol for fuel because it’s not converted to glycogen the way food is. Instead, your body converts the energy from alcohol into fat.

Related: What Swimmers Should Eat Before, During & After Swimming

One drink here and there won’t totally derail your fitness and nutrition goals, but it’s important to understand what you’re consuming and how it fits into your daily nutrition plan. 

Alcohol has about seven calories per gram, which means that a single, one-ounce shot of vodka has about 65 calories. Combine that with any sugary mixers, and a few drinks can add up quickly.

Brain & Mental Health

Alcohol molecules can easily pass through the blood-brain barrier, which has a major impact on the brain and your mental health.

Alcohol reduces the production of the neurotransmitter GABA in the brain, which helps to regulate the nervous system. 

When alcohol binds to GABA receptors in the brain, you might experience heightened anxiety, slurred speech, loss of motor skills, blurred vision and more.

If you drink consistently, your brain may adapt by reducing GABA receptors, which can result in longer-term anxiety, irritability and other mental health issues.

Affects Your Routine

Many top athletes don’t drink alcohol during their competition season (and some don’t drink at all!). When they do choose to drink, it’s in moderation, because one crazy night of drinking can impact their performance for hours and days into the future. 

Related: Why You Need a Structured Swim Training Plan

Think about it…if you have 168 hours in a week and you start the week with a massive hangover, your performance could suffer for 72 of those 168 hours! That’s 42% of your week. If you’re serious about improving your performance, consider reducing your alcohol intake. 

To perform to the best of your abilities, it’s best not to drink alcohol at least 48 hours before sporting activity or competition.

The Best Way to Hydrate for a Swim Workout

Now that we understand how alcohol impacts the body and how much it can dehydrate you, let’s take a look at the best way to hydrate for optimal performance, according to the American Council on Exercise.

  • Before a Workout: Drink 17 to 20 ounces of water 2 hours before exercise.
  • During a Workout: Drink 7 to 10 ounces of fluid every 10 to 20 minutes during exercise. This is a great opportunity to add electrolytes to your water or drink a sports drink if you sweat a lot. 
  • After a Workout: Drink 16 to 24 ounces of fluid for every pound of body weight lost after exercise.

Your body is made up of 60% water, so make sure to fuel it responsibly! Share your thoughts, tips and tricks in the comments. For more swimming tips, technique videos and customized workouts, download the MySwimPro app!



  1. …” After a Workout: Drink 16 to 24 ounces of fluid for every pound of body weight lost after exercise.”
    So does this mean I’m supposed to weigh myself after every swim to determine how much water to consume??? I don’t lose weight like this. I usually weigh the same amount before/after swimming. Please clarify.

    • Some people do find it helpful to weigh themselves a few times to see if they lose a few pounds of water weight due to sweat, which can help give them a baseline for post-workout hydration. If you aren’t comfortable weighing yourself, just make sure to drink lots of water after a workout!

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