Trainers know that your body doesn’t perform optimally for a couple days after a big night out. A study in rats found that high-dose alcohol consumption depleted their calf and psoas muscles by 20 percent. Their hearts weighed 10 percent less, too! These are rat studies, of course, but the indication is that too much heavy drinking for prolonged periods can hurt muscular and heart function in the long run. That occasional glass of wine is great for heart health and can even boost brain power—but those benefits go out the window when you overdo it.
MORE: How Alcohol Sabotages Your Fitness Goals