How can your body yearn for a beverage that sabotages your efforts?
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For years, I've often felt an odd craving after I work out: The desire to drink. Not water. Not a protein shake. Not a sugary, electrolyte-laden sports drink. Alcohol. The stuff that poisons the liver and dulls the mind, but in the form of an ice-cold IPA or a crisp gin and tonic nevertheless refreshes the spirit.
It's a craving that I find difficult to resist, and one that, as a certified fitness professional, is more than a little disconcerting. How can my body, which I condition daily to become fitter, faster, and stronger than the day before, rebel against my programming and yearn for a beverage that can sabotage my efforts?
That's not a rhetorical question. I've asked it many times to many people with many more abbreviations after their names than I have—some of whom, like Jakob Vingren, PhD, CSCS, FACSM, have devoted their careers to answering it. And the most comforting response I've received thus far is that I'm not alone. "The research is pretty clear," says Vingren, an associate professor of exercise physiology and biological sciences at the University of North Texas, and perhaps the world's foremost authority on the effect of alcohol on athletic performance. "People who are physically active tend to drink more than people who are not."
The first time I heard that, I called bullshit. It flies in the face of common sense. Healthy habits beget healthy habits, after all, so if someone exercises regularly, it stands to reason that they're also going to eat more healthfully, sleep more adequately, and not drink fucking alcohol after they work out. But Vingren assures me that I'm wrong.
There are plenty of possible explanations for why exercising might inspire drinking. If you're a team player, the social pressures associated with group behavior might push you to the bottle, for example. It's also possible that since alcohol and exercise activate the same reward mechanism in the brain, working out regularly increases the likelihood that you'll seek a similar "fix" through drinking. "But the reality is that no one has been able to prove a direct cause and effect," Vingren says.
What science has been able to prove with a fair degree of certainty is that exercise frequency tends to influence drinking volume—the more consistently you sweat, the more likely you are to be a tippler than a teetotaler. You're also more likely to imbibe on days that you work out than on days that you don't, according to scientists at Pennsylvania State University. And that's where the problem lies—drinking after you exercise.
For guys, there might be a relatively simple explanation: Consuming alcohol after you hit the gym can elevate testosterone levels. That might sound positive—testosterone, after all, is an anabolic (i.e., growth promoting) hormone—until you understand what's behind it. "The reason we see an elevation in testosterone might be because alcohol interferes with the ability of testosterone to bind to its receptors on muscle cells," Vingren says.
If testosterone can't bind to its receptors, then it can't signal cells to regulate protein synthesis (aka muscle growth), and more of it circulates uselessly in the blood. The effect isn't trivial: In a study of Australian athletes, researchers found that drinking alcohol after strength training can reduce muscle protein synthesis by 37 percent.
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It gets worse: Alcohol can also interfere directly with cells' ability to manufacture proteins. "So it suppresses both the signal that helps to regulate protein synthesis and the translation of that signal," Vingren says. For those of you keeping score, that's two strikes against drinking when it comes to building muscle—if you're a guy.
"With women, it's different," adds Vingren, who has conducted one of the only studies investigating the effects of alcohol ingestion on training adaptations in both men and women. "We either see no effect or a slight increase in concentric strength with alcohol consumption during the recovery period."
Vingren doesn't have a good explanation for the gender difference. "It's one of those areas where more research is needed," he says, admitting that the results from his single, relatively small study might be off. "But the bottom line is that if you're a guy, and you're going to go out and drink, you might be better off not going to the gym beforehand because your recovery is going to be delayed."
The female advantage disappears with cardiovascular exercise. Drinking alcohol after a run (or a bike ride, or a swim, or any other aerobic endeavor) will hamper your recovery regardless of whether you have a Y chromosome or two Xs. The reason is that alcohol appears to interfere with the body's ability to replenish supplies of its primary fuel source—glycogen, Vingren says. The longer it takes to restock glycogen (the stored form of glucose, which your body creates from carbs), the longer you'll need to recover between workouts.
At this point, you might understandably assume that you're screwed any way you look at it. If you exercise regularly, you're more likely to drink—especially on the days that you work out. And if you drink after you work out, you're essentially engaging in self-sabotage, erasing any sweat equity you earned that day. But here's the thing: All of the studies mentioned above—indeed, nearly every study that seems to condemn post-workout imbibing—involve binge drinking, not responsible tippling. The athletes in the Australian study, for example, knocked back 12 extra-strong screwdrivers after they worked out (six immediately after exercise, and six more four hours later).
"There definitely seems to be a dose-dependent relationship," Vingren says. "Drinking a glass of wine with dinner likely won't cause any major issues." The problem occurs when you regularly have two or more drinks after working up a sweat. "Each time you drink after going to the gym, your gains will be slightly diminished, and that can add up over time," says Vingren. "That doesn't mean you have to give up alcohol—just moderate your intake."
A post-workout shake can also help. That same Australian study found that when subjects consumed protein (in the form of 25 grams of whey powder) prior to consuming alcohol, muscle protein synthesis was reduced by 24-percent instead of 31 percent. A 13-percent difference might not sound like much, but in the weight room, it can mean the difference between benching as usual and throwing a couple more plates on the bar.
"Blood alcohol concentration also seems to be important," Vingren says. "If you have five drinks, but you spread them out over five or six hours, that will have less of an effect than if you drink them all in ten minutes."
Noted. But if you're like me, that's not even an issue. My bender days are long behind me, and the thought of drinking 12 screwdrivers in an evening—or trying to match an Aussie footballer drink-for-drink under any circumstance—makes my stomach turn. But I'll tell you this: If I occasionally feel like having Highland IPA or a gin highball after I work out, I'm not going to deny myself. I'm just going to make sure I have a protein shake first.
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