Alcohol is a tricky subject, even for people who've been seriously working on their fitness for years. Alcohol (and its stimulant counterpart caffeine) is a central part of Western social and business life. In our Kenzai programs we stay away from alcohol for a simple reason; it packs in a lot of calories in liquid form. The brain is exceedingly bad at understanding how much energy we're consuming when we take it in as a liquid. You can easily drain 500 calories of alcohol (roughly 3 beers) while, if you ate 500 calories of food, (a burger and fries) you'd feel quite full.
Beyond calories, there's another insidious effect of alcohol. When you go to sleep with alcohol in your system, your body isn't truly resting.
Your heart rate is elevated and your liver is working hard to purge the toxin from your blood. This alone will chop off an hour or two of rest and repair function. But the problems only get deeper from there.
You might feel that you drop into a deep sleep after a few drinks, but research shows that alcohol induced sleep is of the lowest quality.
The brainwaves of someone sleeping after a few drinks is similar to someone under anesthesia. You're not going through the normal stages of sleep (stage 1, stage 2, delta sleep and REM), you're just knocked out cold. This means your body isn't activating the usual pattern of tissue clean up and muscle cell buffering. You're also not getting the memory and learning boosts of REM sleep. Sleep is supposed to be a time of rejuvenation and intellectual growth. Alcohol robs you of those benefits.
If you want to avoid the worst effects of alcohol, keep the "one drink one hour" rule. It takes your body about an hour to metabolize one unit of alcohol (1 beer, 1 glass of wine, or 1 serving of hard liquor). So if you have 3 glasses of wine you know that your body will be dealing with that input for at least three hours. Above all else avoid an alcohol consumption that pushes your metabolization past your bedtime. For example if you want to go to sleep at 11, you'd need to finish your third and final glass of wine by 8 pm.
However, even following the "one drink one hour" rule, you'll still have reduced quality sleep, with more frequent awakenings and shortened REM for up to TEN hours past your last drink. This means that if you want to have a drink and guarantee the highest-quality sleep, you need to get your alcohol down before 1 pm (with an 11 pm bedtime)! As sleep expert Matthew Walker tells his college students, all things considered, if you're going to drink, it's healthier to have your drinks in the morning. Have fun explaining that to your boss!
Alcohol presents so many problems for sleep health and tissue repair that it's really hard to justify, especially when you're trying to change your body for the better. Take a hard line against it and indulge sparingly.
A beer, wine, or cocktail is served to you with a smile, but it's no friend of your body!