The Truth About Alcohol and Cycling

By Josephine Allen | Cycling Camp San Diego

Source: ACTIVE

Glass of Beer

Glass of Beer

“I’m carb loading” is a joke I often hear (and use!) when reaching for that frosty glass of beer. However deep down we all know this isn’t the truth and while there are energy calories in alcohol (a whole 7 Kcal/g versus 9 Kcal/g in fat and 4 Kcal/g in carbohydrates), alcohol is pretty useless as a short-term energy source, in addition to the fact that it is devoid of any nutrients.

So, let’s look at this simplified explanation of what happens when you drink a few beers:

More: Alcohol: The Benefits and Risks

Toxin alert!

Most of the alcohol in the beer heads into your bloodstream and is immediately treated as a toxin by your body. Where do toxins end up? In the liver!

Feeling Tipsy?

The liver gets to work straight away metabolizing the alcohol using powerful enzymes, but there’s only so much enzyme capacity in there, so any excess alcohol circulates your blood stream waiting for its time to come to be metabolized. In the meantime it plays havoc with your heart, brain, other tissues and organs (legs muscles go a bit wobbly, brain a bit more relaxed, reaction time not so cat like…sound familiar?).

More: Alcohol, Athletes and the Pressure to Drink

Glycogen Replenishment Halts

In addition to the alcohol consumed there’s also a good dose of carbohydrates in beer. “No problem! That’s my recovery fuel” I hear you say. Sadly—no, it doesn’t work this way. Since the liver enzymes are working at full speed to rid your body of the alcohol toxins they aren’t available to be used for normal energy metabolism functions and glucose conversion to glycogen grinds to a halt (glycogen being the stored form of glucose in your muscles).

Fat Stores

In the same way that the body doesn’t like a heap of alcohol to be swimming around in your blood it also won’t tolerate a load of excess glucose in there either. So, your body goes all out to lower the blood glucose levels too, but since the excess glucose can’t be metabolized into glycogen…where does it go? Fat stores, I’m afraid.

More: What Does Your Sweat Taste Like?

Got the Munchies?

Only once all the alcohol has been dealt with can your body return to normal and start slowly tapping into those fat stores and replenishing glycogen depleted muscles. The body metabolizes alcohol at roughly 7g-15g of alcohol/hour and a 12-ounce bottle of beer will have somewhere between 10g and 14g of alcohol in there. That means if you have a few beers it could be 3-4 hours before your body can even start to deal with the carbohydrate you consumed in the beer and even longer before it gets around to dealing with that burrito that seemed like such a good idea afterwards.

More: Eat Like a Champion

Sleep Patterns Affected

The low blood glucose levels caused by the alcohol in your body can have a serious effect on sleep patterns too. REM sleep is disturbed and this is the sleep cycle where you consolidate and commit to long-term memory everything that happened during the day.


Antidiuretic hormones which normally prevent too much urine being created are reduced in the body when you drink alcohol, the resulting effect being excess urine production, dehydration… and of course several trips to the bathroom in the night which compound your already disturbed sleep!

Dehydration continues well after alcohol consumption and since as little as a 2-percent decrease in body water weight can have a significant impact on performance this is certainly going affect your Strava time the following day.

More: What Does Your Sweat Taste Like?

Muscle Growth is Affected

Lack of sleep not only turns me into the human equivalent of a caged tiger being poked with a big stick but the double whammy here is that less sleep equals less HGH being produced by the body. What does HGH do? Exactly what the name Human Growth Hormone suggests—builds muscles. Reducing what is naturally produced in the body to build muscle is clearly a performance decreasing strategy.

Cortisol Production Increases

Cortisol (a useful “fight or flight” hormone which increases with stress levels) increases when you drink alcohol. While you may be having a merry old time while you’re in the pub, the aftermath on your system can be dramatic. Increased cortisol negatively affects testosterone levels and being in a prolonged and unnecessary state of “I’m ready to flee from an attacking rhinoceros” can’t be good for anyone.

Testosterone Production is Reduced

Studies have shown that consuming alcohol leads to a dip in testosterone (i.e. post-riding drinking could really affect that period of muscle growth after a training ride). And don’t be fooled by thinking testosterone is only a guy issue. Sadly this isn’t the case; girls need it too for muscle development.

Oh dear, this really is kind of depressing isn’t it? So, what’s the answer? Never letting a drop pass your lips again? Maybe—but remember life’s for having fun and sometimes the mood-enhancing benefits of a few drinks with good friends can far outweigh the physical downsides. I’m a great believer in “all things in moderation” and while I can’t claim that drinking is going to improve performance most of us aren’t competing at a pro level and the odd drink or two isn’t going to ruin our lives.

More: Fluid Facts for Athletes

So here’s a few “real world” suggestions as an alternative to giving it up entirely:

  1. Avoiding unnecessary drinking e.g. the “It’s 6 p.m. and a fancy a beer because the day ends in Y” type drinking. Save it for memorable occasions.
  2. Avoid post- or pre-ride alcohol and if you are going to drink after a ride make sure you get some useful carbs into your system first to kick off the recovery process.
  3. Go for light beers or something like a gin and low cal tonic.
  4. Drink a glass of water between every alcoholic drink.
  5. Try to avoid drinking the night before a hard / hot training ride or if you are suffering a bit the morning after a few drinks make sure you eat a good breakfast and drink lots of water before and during exercise.

I should also note that there is research out there which puts a positive spin on drinking, such as heart benefits of red wine, plus studies that suggest low quantity/high frequency drinking subjects are leaner than non drinkers. However, I’m inclined to believe that anything that your body treats as a toxin really can’t be that good for you and it’s best to consider the occasional beer/wine as a treat rather than a nutritional must have.

More: Running on Empty Bottles