A Sports Cardiologist Explains When—and Why—to Cut Out Alcohol So You Can Run Stronger on Race Day

Waiting until you cross the finish line to toast with your running buddies can set you up for better sleep, more energy, and faster splits.

By Morgan Petruny, Mallory Creveling, CPTPublished: Sep 07, 2026 2:56 PM EDT

Whether you’re racing the mile or the marathon, dozens of factors can influence how you perform on race day. One thing that almost certainly won’t help you clock a faster finish: alcohol.

To understand how drinking can affect your training and running performance, we spoke with Tamanna Singh, MD, director of Cleveland Clinic’s Sports Cardiology Center and codirector of its Women’s Integrated Sports, Exercise, and Research (WISER) Center, RRCA-certified run coach, and marathoner.

Singh explains exactly why and when you’ll want to cut out booze as you prepare for a race, so you show up on the starting line ready to run your best. You’ll also learn how alcohol affects two essential tools for recovering well and racing strong.

When Should You Cut Out Alcohol Before a Race?

According to Singh, there’s no hard cutoff for when you need to stop drinking before a race. That said, she explains that there are specific times during your training cycle when alcohol can be especially detrimental to your performance.

“If you’re following a 12- to 16-week training cycle for a marathon, lay off the alcohol from about weeks six to nine, or nine to 12 [respectively],” she says.

Those three to four weeks just before your taper, when you’re hitting those 18- to 20-mile long runs, are when you really want to be prioritizing your recovery, Singh explains. That includes getting high-quality sleep, adequate hydration, and ensuring good heart-rate recovery and variability—all things that alcohol can significantly impair.

Most runners will usually taper for about two to three weeks before their race, Singh adds, and that’s also a time you’ll want to avoid booze. “During that time, you really want to have a good reset for your body so it can focus on muscle repair, synthesis, and recovery,” she says. Because alcohol affects all those factors, many people won’t drink during that time—and plenty of athletes just don’t drink at all during their entire training cycle. This allows you to train hard, recover well, and show up fresh and ready to race!

How Does Alcohol Affect Your Energy?

The days leading up to your race are a key time to focus on getting enough carbohydrates, fluids, and electrolytes. Doing so helps prime your body to hit that starting line strong, explains Singh. Physiologically, having a beer during this time can interfere with your efforts to stay adequately fueled and hydrated.

“Alcohol is metabolized by the liver, and essentially the liver is the organ that’s responsible for getting rid of all of the body’s toxins,” Singh says. When you drink, the liver needs to clear that alcohol first, which requires your body to use glucose. The problem is that you also need that glucose for energy to run well and hit your goal race paces.

“If you have alcohol in your system, your liver is going to prioritize breaking down that alcohol instead of providing glucose for you to utilize for energy,” Singh says. With less glucose available to fuel your working muscles, maintaining your usual pace can feel noticeably harder.

So, instead of having a drink in the days or weeks leading up to your race and risking more fatigue than you want on your big day, wait until you cross the finish line to celebrate with a postrace beverage, Singh says.

How Does Alcohol Affect Recovery?

Booze can also wreak havoc on your sleep, which many experts consider the single most powerful tool runners have to improve their recovery.

“Alcohol impairs the ability for the body’s muscles to repair, synthesize, and recover while we sleep,” Singh says. “It actually inhibits growth hormone, which is responsible for all of that muscle recovery.”

Not only does alcohol lower your sleep quality, but it can also cause insomnia for some individuals, which can mean sleep quantity suffers, too. In order to perform well day after day in training, you really need both good sleep quality and adequate sleep quantity, adds Singh, or you won’t be able to perform.

Even one night of poor sleep can affect your running the next day. In a study published in Physiology & Behavior, researchers asked 20 runners to complete a 12-minute, self-paced time trial after getting eight hours of sleep and again after getting just four hours. After the night of less shuteye, the runners covered 6 percent less distance and reported a higher rate of perceived exertion, more fatigue, and worse overall mood.

Finally, alcohol can also lower your heart rate variability (HRV). HRV reflects the balance and activity of your sympathetic (“fight or flight”) and parasympathetic (“rest and digest”) nervous systems as your body responds to changing demands throughout the day. A higher HRV generally indicates that those systems are well-regulated, which can signal better recovery and cardiovascular fitness, Singh explains.

All things considered, alcohol delivers a harsh double whammy to your running recovery and your overall fitness. When you’re preparing for a race, it can be a huge benefit to eliminate booze from your training plan entirely. You might just find yourself crossing the finish line a little faster and stronger—which will make that postrace toast with your running buddies all the sweeter.