Flying can be a taxing experience, often leading passengers to indulge in a pre-nap cocktail, hoping to catch some much-needed Zs above the clouds. However, a recent study reveals that this common practice may turn your dreams of a relaxing vacation into a heart-pounding nightmare.

Researchers found that consuming alcohol before sleeping on a flight can significantly lower blood oxygen levels and increase heart rates, even in the young and healthy. Yes, even if your abs are Instagram-ready, your heart might not be too thrilled about that in-flight Bloody Mary. The study indicates that the combination of alcohol intake and low cabin pressure challenges the cardiovascular system, potentially exacerbating symptoms in patients with cardiac or pulmonary diseases. In short, that little bottle of wine might be putting your body through an impromptu triathlon while you snooze.

Moreover, blood oxygen saturation can drop to concerning levels when alcohol is consumed before sleeping at flight altitudes, posing a significant risk for individuals with pre-existing medical conditions. Essentially, at 35,000 feet, your body isn’t such a fan of alcohol, making even the most seasoned travelers rethink their in-flight beverage choices.

But wait, it gets better—or worse, depending on how you look at it. The study further reveals that time in REM sleep is reduced and sleep quality is negatively affected when alcohol is consumed before sleeping at flight altitudes. So, while you may think that glass of Chardonnay is helping you drift off to dreamland, it might actually be locking you in a cycle of fragmented sleep and knocking significant time off your REM, the phase when your brain does its essential housekeeping.

The study involved 48 healthy adults who were tested by sleeping in both sea level and altitude-simulated environments over two nights, with and without alcohol intake. This controlled setting provided a thorough look into how alcohol consumption at high altitudes can complicate one’s cardiovascular system.

The findings have significant implications, suggesting that alcohol consumption on board airplanes is an underestimated health risk. Researchers have gone so far as to recommend considering regulatory changes to restrict access to alcoholic beverages on flights. Whether this will lead to a future in which alcohol is as elusive as legroom remains to be seen.

In the heart of this aerial turmoil is the expert advice urging travelers to avoid consuming alcohol on airplanes to prevent potential health risks, including the exacerbation of underlying health conditions. Perhaps the next time you’re reaching for that complimentary champagne, you might want to consider a sparkling water instead.

In hindsight, drinking alcohol to fall asleep on a plane might not be the wisest idea. The study clearly indicates poorer sleep quality overall, with travelers experiencing more fragmented sleep and reduced REM sleep. So, while a pre-flight drink might ease the boredom of waiting at the gate, it turns out that in the air, it might pave the way to sleepless nights and heart-related frights.

Ultimately, the choice is yours: the short-lived joy of a glass of pinot noir at 30,000 feet, or a heart that's rhythmically partying while you're trying to nap. It’s an easy mistake to make—who knew your heart could be such a buzzkill?