We don't need a study to tell us that people who work out more drink more (although the studies tell us that anyway). But what, exactly, does imbibing after a workout do to exercise’s benefits? And how much is enough to offset your gains?
According to a small new study, you can completely erase a strength workout's gains if you get drunk. Cap it at a couple of drinks, a glass or two of wine or beer, and you're likely in the clear.
To assess the effects of alcohol on muscles, researchers at the University of North Texas recruited 10 men and nine women, all of whom worked out regularly. On two separate occasions, they took muscle biopsies from the participants before having them complete a rigorous squat routine with weights. After one workout, they were given plain water. After the other, they were quickly fed enough vodka to get them drunk. Depending on body size, it took four to eight drinks to get everyone’s blood alcohol level to 0.11, exceeding the legal driving limit.
Then, three and five hours after each strength workout, the researchers took an additional tissue sample from each volunteer. This allowed them to compare what would normally happen within the muscles following intense strength training versus what happens with lots of alcohol in the mix.
They discovered that in the men, but not the women, booze interfered with the mTORC1 signaling pathway, which is instrumental in muscle repair and growth. “When the men drank only water, the activation of this pathway increased, which is what you’d hope to see after exercise,” says lead study author Jakob Vingren. “But after consuming alcohol, there was no increase in activation. So basically, alcohol prevented it from rising above rest.”
It’s unclear why the women’s muscle recovery wasn’t hindered in this way, but Vingren says it may have to do with testosterone. Men, of course, generally have more of this hormone than women. “We know for sure that testosterone affects the mTORC1 pathway,” he says. “We know for sure that exercise affects the mTORC1. So it’s reasonable that testosterone may be involved somehow.” Vingren believes alcohol might mess with testosterone receptors, blocking the hormone from stimulating muscle repair via that pathway.
Although this particular study didn’t look at the effects of only one or two drinks after strength training, Vingren says it shouldn’t be a problem. “We only really see these effects after large doses of alcohol,” he says. “So if you’re planning on going out on the town and drinking a lot, I wouldn’t recommend heavy-duty lifting beforehand, or vice versa. But having one or two beers or glasses of wine after strength training is probably okay.”
A few drinks also shouldn’t hinder your strength-training performance the next day, Vingren adds. “The evidence suggests alcohol may hinder aerobic performance and endurance, but it doesn’t have much effect on strength or power,” he says. “This is all good news for people who like a drink after the gym — alcohol is not as bad for your muscles as the rap it gets.”